ergospirometry

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CPETCPETCPETCPETCPETVarious fields of application

Special Edition:Cardiopulmonary Exercise Testing

Information, Diagnostics, Essays

Vmax und CardiosoftVmax und CardiosoftVmax und CardiosoftVmax und CardiosoftVmax und CardiosoftCPET made by SensorMedics,ECG made by Marquette Hellige

2 VIASYS info Special Edition CPET, April 2002

Editorial

Table of Contents

Paul ter GroteManaging Director of Erich JAEGER GmbH,

a subsidiary of VIASYS Healthcare

Dear readers,It has always been the wish of mankind to go to the limits ofour capacities. Even the ancient Greeks used to send messagesthrough couriers who were able to run hundreds of miles in acouple of days. If the first marathon runner in history had hadour knowledge and had been trained according to current stan-dards, he would not have collapsed of exhaustion after havingbeen informed of the first Athenian victory over the Persiantroops in 490 b.c. However, despite our medical findings, car-diopulmonary exercise testing is still a fascinating subject forphysicians and researchers of various medical fields.This first special VIASYS info edition is especially aimed atclinicians who wish to be informed about reasons, indicationsand interpretation of cardiopulmonary exercise testing and whoare interested in their collegues' research findings.Apart from its application in athletic performance, cardiopul-monary exercise testing can be used in various medical fields(an overview of which is provided on page 8). Until now, exer-cise testing has only been practiced by experts. Today we seean increasing interest from healthcare providers. We hope toinform you with interesting literature suitable to support youin your daily work. If you are interested in learning more aboutcardiopulmonary exercise testing - please read through our bro-chure or simply refer to the literature references on page 31.

Sincerely Yours,

EssayExercise Testing: The "How" and the "Why"Author: Prof. Brian J. Whipp Ph.D., D.Sc. .............................. 3

Fields of ApplicationCPET - Various Fields of ApplicationIndications and relevance of CPET .......................................... 8

DiagnosticsOxycon ProCPET of the Highest Quality .................................................. 10

Practical GuidelinesCPET- Practical GuidelineAuthor: Wolfgang Mitlehner, M.D. ........................................ 12

DiagnosticsVmax and CardiosoftCPET made by SensorMedics,ECG made by Marquette Hellige ........................................... 20

Oxycon Mobile ....................................................................... 23

EssayClinical Relevance of CPETAuthor: Prof. Karl-Heinz R¸hle, M.D. .................................. 24

EssayEvaluation and Interpretationof a cardiopulmonary exercise testAuthor: Hermann Eschenbacher, Ph.D. ................................. 26

The Last PageLiterature references, Training courses, seminars .................. 31

CPETCPETCPETCPETCPETHistory, approaches and applications

3VIASYS info Special Edition CPET, April 2002

2.2.2.2.2. IntrIntrIntrIntrIntroductionoductionoductionoductionoductionThe tolerable range of work rates in patients with lung disease is constrained by a com-bination of factors, chief of which are:a) impaired pulmonary-mechanical and gas exchange function which increases the de-

mand for airflow and ventilation;b) limitations in response capabilities, either of airflow generation or of lung distensi-

on;c) increased physiological costs of meeting the ventilatory responses, in terms of respi-

ratory muscle work, blood flow and O2 consumption;d) predisposition to 'shortness of breath' or 'dyspnoea' as a consequence of the high

fraction of the achievable ventilation demanded by the work rate, commonly exacer-bated by arterial hypoxaemia; and

e) the often-marked reduction in the range of spontaneously-selected daily activities,which results from the dyspnoea, and further reduces the state of physical training.

Brian J. Whipp, Ph.D., D.Sc.Centre for Exercise Science andMedicine, University of Glasgow,Glasgow, UK

Essay

1.1.1.1.1. AimsAimsAimsAimsAimsTo address the role of exercise testing in elucidating the causes of exercise intolerance,with particular reference to pulmonary disease.To discuss the value of clinical exercise testing, in:a) establishing the limits of system functionb) defining the effective operating rangec) identifying potential causes of exercise intoleranced) evaluating the normalcy of the response with regard to a reference populatione) establishing the normalcy of response with regard to other physiological

functionsf) providing a frame of reference for change with respect to therapeutic

interventions or training, andg) as a means of "triggering" an abnormality.To emphasise the importance of domains of exercise intensity and identifying thedeterminants of an "appropriate" ventilatory response, including considerations of:a) to what extent are the "requirements" met?b) what is the "cost" of meeting these requirements?c) to what extent is the system "constrained" or "limited"? andd) how "intensely" is the response perceived?To establish the physiological basis of the profiles of cardiopulmonary system responsesto incremental exercise performed to the limit of tolerance.To recognise when the value of a particular variable or its response profile reflects anabnormality of system(s) functioning, both with respect to(a) the work rate itself or to other related variables and(b) consideration of responses that are often misrepresented as reflecting systems

behaviour.

Exercise TExercise TExercise TExercise TExercise Testing: The "How" and the "Why"esting: The "How" and the "Why"esting: The "How" and the "Why"esting: The "How" and the "Why"esting: The "How" and the "Why"

Strategies designed to increase exercisetolerance in such patients should thereforeattempt both to increase (where possible) theventilatory limits, reduce the demand forventilation and reduce the intensity of, orattempt to desensitize the subject to, theconsequent dyspnoea.In order to meet the increased demands forpulmonary gas exchange during exercise, thelungs must replenish the O2 extracted fromthe alveoli by the increased flow of moredesaturated mixed venous blood. Thispreserves alveolar, and hence arterial, O2partial pressure. The lungs must also provideto the alveoli diluting quantities of CO2-free(atmospheric) air at rates commensurate withthe increased delivery rate of CO2 in themixed venous blood. This maintains alveolar,and hence arterial, PCO2. However, themetabolic (chiefly lactic) acidosis of high-intensity exercise requires that alveolar andarterial PCO2 be reduced to provide acomponent of respiratory compensationwhich constrains the fall of arterial pH.The pulmonary system is therefore confron-ted by different demands for blood-gas andacid-base regulation during exercise. Thereare competing ventilatory demands for alve-olar PO2 and PCO2 regulation when the re-spiratory exchange ratio differs from unity,and also for arterial PCO2 and pH regulationwhen the exercise results in a metabolic aci-dosis. In patients with lung disease, this pro-cess is further complicated by pulmonary gasexchange inefficiencies which result in of-ten-marked differences between alveolar(either ëidealí or ërealí) and arterial gas par-tial pressures. Consequently, the impairedpulmonary gas exchange in patients withchronic lung disease further increases theventilatory demand during exercise; the im-paired pulmonary mechanics, however, cons-trains or even limits the ability to meet thedemands.


However, as ATL estimation does not requiresuch efforts, it therefore provides:a) an index of the functional status of the

respiratory-circulatory-metabolic inte-gration that allows exercise to besustained aerobically;

b) an index of sustainability for a particulartask;

c) a frame of reference for optimizing train-ing protocols;

d) an index of the efficacy of physical train-ing, rehabilitation and drug interventions;and

e) an essential component of decision-mak-ing strategies for elucidating the domi-nant system(s) responsible for exertionaldyspnoea and exercise intolerance.

Essay

"The challenge is to select exercise tes-"The challenge is to select exercise tes-"The challenge is to select exercise tes-"The challenge is to select exercise tes-"The challenge is to select exercise tes-ting procedures that optimize the stressting procedures that optimize the stressting procedures that optimize the stressting procedures that optimize the stressting procedures that optimize the stressprofile..."profile..."profile..."profile..."profile..."

"There is no generally-agreed upon pro-"There is no generally-agreed upon pro-"There is no generally-agreed upon pro-"There is no generally-agreed upon pro-"There is no generally-agreed upon pro-cedure for normalizing work intensitycedure for normalizing work intensitycedure for normalizing work intensitycedure for normalizing work intensitycedure for normalizing work intensity..."..."..."..."..."

Therefore ATL has proven to be a useful in-dex of the onset of an exercise-induced me-tabolic acidaemia. One can forego the neces-sity for serial blood sampling and even, inmany cases, enhance the discriminability ofATL by utilizing a particular cluster of venti-latory and pulmonary gas-exchange, whichprovides noninvasive estimation of ATL. ATLdiscriminability, however, under "complica-ting" conditions such as chronic hyperventi-lation syndromes, progressive exercise-in-duced hypoxaemia, or impaired peripheralchemosensitivity with an associated high air-way resistance, for example, remain to be es-tablished.Although there is no generally-agreed uponprocedure for normalizing work intensity,most would concede that moderate exercisemay be sustained for long periods but heavyor severe exercise may not. The measured orappropriately-estimated degree of metabolic

acidaemia can be used as a defensible indexof exercise intensity.That is, three intensity domains may usefullybe identified:a) moderate - work rates below ATL, with

no increase in arterial blood [lactate] or[H+] and steady states of ventilation andpulmonary gas exchange being achiev-able;

b) heavy - that range of work rates aboveATL, for which [lactate] and [H+] are ele-vated, and can achieve a steady state;and

c) severe - even higher work rates, for which[lactate] and [H+] increase inexorablythroughout the test, and steady states ofventilation and gas exchange are notachieved, V'O2 being set on a trajectoryto V'O2 max.

5. 5. 5. 5. 5. TTTTTest Designest Designest Designest Designest DesignThe appropriateness of the integrated syste-mic responses to the tolerable range of workrates are best studied utilizing incrementalexercise testing, as this allows:a) determination of whether the pattern of

response of particular variables is nor-mal with respect to other variables or towork rate;

b) the establishment of a subjectís limitingor maximum attainable value for physi-ological variables of interest; and

c) the establishment of exercise intensitydomains, such as the transition betweenmoderate and heavy intensity exercise.It does this by providing a progressive,gradational stress that spans the tolerab-le work rate range. This minimizes or ob-viates the effects of sudden and large in-crements (that would be less well tolera-ted by many patients).

Although exercise testing should ideally betask-specific, laboratory exercise testing isusually confined to treadmill and cycle-ergometer exercise. Regular and accuratecalibration is important. The motor-driventreadmill imposes progressively increasingstress through various combinations of speedand grade incrementation. An advantage ofthe treadmill over the cycle ergometer is therecruitment of a larger muscle mass whichcauses more marked system stress, withV'O2max being some 5-10% higher than forthe cycle ergometer. A major disadvantageof the treadmill is the difficulty of accuratelyquantifying the power. This reflects thedifficulty of providing a metabolic equivalentof the grade and speed profile, coupled withindividual variations in body weight, walkingefficiency, pacing strategy and thecontribution from holding on to the treadmillhandrails. These factors can substantially

3. Exer3. Exer3. Exer3. Exer3. Exercise cise cise cise cise TTTTTestingestingestingestingestingThe principle that underlies strategies ofclinical exercise testing is that system failuretypically occurs while the system is understress. The challenge is to select exercisetesting procedures that optimize the stressprofile. A major objective of exercise testing,therefore, is to observe the patient and makemeasurements of ventilation and gasexchange to distinguish among thepathophysiological mechanisms causingdyspnoea and exercise intolerance. A widevariety of tests are available, each being moreor less suitable as a stressor of a particularcomponent of the patientís pathophysiology.However, the appropriateness of theintegrated systemic responses is best studied(at least, for the initial exercise evaluation)by means of an incremental test, as thisprovides a smooth gradational stress whichspans the entire tolerance range.

4. Exer4. Exer4. Exer4. Exer4. Exercise cise cise cise cise TTTTTolerance and Exerolerance and Exerolerance and Exerolerance and Exerolerance and ExerciseciseciseciseciseIntensityIntensityIntensityIntensityIntensityWhile the tolerable duration of a given workrate is known to depend upon the intensityof the exercise being performed, there is todate no generally-agreed scheme for charac-terizing work intensity. Two widely-used pro-cedures fail to meet the demands of criticalscrutiny in this regard: the "met" incrementand the "percentage" of the maximal O2uptake (V'O2max). The onset of the metabo-lic (lactic) acidaemia of exercise (i.e. the lac-tate threshold ATL) does not occur at a com-mon "met" increment in different individu-als. Consequently, different subjects at thesame "met" level can have markedly diffe-rent degrees of metabolic acidaemia. Simi-larly, while in normal individuals ATL oc-curs at approximately 50% of V'O2 max, thedistribution is very large, with the normalrange extending from 35% to at least 80%.Consequently, if the exercise intensity is as-signed to a particular percentage of V'O2 max(e.g. 70%), then one subject could be exerci-sing at a sub-ATL) work rate and be "com-fortable" whereas another could exhaust atV'O2 max.Often, however, patients may not be able toattain a V'O2 max in the conventional sense(or the investigator may not wish to stressthem to these levels) because of limitationby some system-related perception (e.g. an-gina, dyspnoea, claudicating pain).

"A"A"A"A"ATTTTTLLLLL has proven to be a useful index of has proven to be a useful index of has proven to be a useful index of has proven to be a useful index of has proven to be a useful index ofthe onset of an exercise-induced meta-the onset of an exercise-induced meta-the onset of an exercise-induced meta-the onset of an exercise-induced meta-the onset of an exercise-induced meta-bolic acidaemia..."bolic acidaemia..."bolic acidaemia..."bolic acidaemia..."bolic acidaemia..."


modify the metabolic rate up to anunpredictable degree.

discriminate threshold behavior. More rapidrates of change impose greater strengthdemands, and introduce complexities ofthreshold discrimination resulting fromtransients of CO2 stores wash-in.A range of protocols are available fortreadmill testing. However, therecommendation is for tests that incrementthe work rate at constant rate, with smallincrements providing the best discrimination.It is preferable to employ increments intreadmill grade at a constant speed.After an incremental test has been performed,there are circumstances in which theinvestigator may wish to conduct constant-load testing in order to gain additionalinformation about system response kineticsin different intensity domains. Suchadditional tests should, of course, beperformed on separate occasions.

6. Formatting the Outputs6. Formatting the Outputs6. Formatting the Outputs6. Formatting the Outputs6. Formatting the OutputsHaving performed such a test appropriately,the investigator then needs to format theresults in a manner that optimizes the abilityto discriminate essential response features;i.e. to establish "interpretive clusters" of thevariables of interest. The challenge inassessing the normalcy, or otherwise, of thesystem responses to the exercise is to selectthe appropriate response variables that arethemselves reflective of the particularsystem(s) behavior and to display theirprofiles of response either as a function ofwork rate or within the context of theresponse of a related physiological variables.That is, what the response of a particularvariable means and, often as importantly,what it does not mean.

7. Useful Noninvasive Responses7. Useful Noninvasive Responses7. Useful Noninvasive Responses7. Useful Noninvasive Responses7. Useful Noninvasive Responses VVVVVOOOOO22222-WR r-WR r-WR r-WR r-WR relationshipelationshipelationshipelationshipelationshipIn response to a constant work rate challenge,V'O2 increases exponentially to attain a stea-dy state (over the work rate range for whichsteady states are attainable). The magnitudeof the steady-state increase in V'O2 as func-tion of the work rate increment (i.e.DV'O2/DWR) is considered to be the functional sys-tem "gain" (functional is used here as puristsinsist that gain has no units). This gain isfunctionally the inverse of the work efficien-cy, the difference being that in the efficiencycomputation DV'O2 is transformed into itsenergy equivalent by taking into account thesubstrate mixture undergoing oxidation, i.e.the gain is higher for fatty acid oxidation thanfor carbohydrate whereas the actual workefficiency is not different.

For incremental exercise tests of the ramptype, a constant rate of change of WR re-places the constant absolute WR as the chal-lenge. Consequently, this yields a constantrate of change of (i.e. linear with respect totime and therefore WR) after a small lag-phase which reflects the system response ki-netics.The O2 gain has been shown (at least inhealthy subjects) not to differ from that ofthe steady-state response (normally 9-11 ml/min/Watt). The value of V'O2 at any workrate on a ramp test is therefore lower thanthat for the steady state at that work rate, al-though its rate of change is normally thesame. The incremental gain is therefore of-ten used as an index of the work efficiency.However, in many patients with cardiopul-monary diseases, this incremental gain canbe very low (e.g. 8 ml/min/Watt or less). Thismay be interpreted in one of two ways:(a) The intramuscular energy transduction

mechanisms linking ATP production tooxygen utilization have become Ñhyper-efficientì (an unlikely scenario) or

(b) that unlike healthy subjects, the time con-stant of response is not a constant irres-pective of WR but rather may lengthenas WR increases. Remarkably, to date,the criteria that justify the incrementalgain as being reflective of the steady-stategain have never been established, exceptin healthy subjects.

The highest value achieved with good sub-ject effort is termed the "PeakV'O2(VO2peak). In those instances in which V'O2does not continue to increase with furtherincreases in WR (i.e. a plateauing results)yields what is termed the maximal V'O2(V'O2max). Plateaux of V'O2, however, seemnot to be common, such that without evidencefrom other tests that the highest attainedmeets the original criterion for V'O2 max, thevalue should be reported as V'O2 peak. It isimportant to recognise, however, that whileV'O2 max is not different with different rampslopes the maximum work rate attained isprogressively greater the faster the ramp.

Essay

"Electronically-braked cycle ergometry"Electronically-braked cycle ergometry"Electronically-braked cycle ergometry"Electronically-braked cycle ergometry"Electronically-braked cycle ergometrywith a reasonable constant pedaling fre-with a reasonable constant pedaling fre-with a reasonable constant pedaling fre-with a reasonable constant pedaling fre-with a reasonable constant pedaling fre-quency is recommended..."quency is recommended..."quency is recommended..."quency is recommended..."quency is recommended..."

The cycle ergometer has several advantages:lower cost, less space, less prone to move-ment artifacts, and more accurate quantifi-cation of power. A variable contribution tothe oxygen cost of cycling at unloaded pe-daling; i.e. largely a function of the weightof the legs. However, if the pedaling cadenceremains essentially constant throughout thetest, this amount becomes a constant for allwork rates and therefore does not influencethe oxygen cost associated with a particularwork-rate increment. Electrically-braked cy-cle ergometers are becoming increasinglypopular, although the older friction- brakedversions are adequate (recalling, of course,that the power depends on the pedaling rate).The electrically-braked models have the con-siderable advantage that power is indepen-dent of pedaling frequency, typically overquite a wide range, and that work rate cont-rol can be implemented remotely by a com-puter.Technological advances have made itpossible for sufficient density of data forrigorous response-profile discrimination tobe acquired in a test lasting less than 20 min.Such a test should include the followingphases:a) restb) at least 3 min. of unloaded exercisec) incremental exercise (~10-12 min), andd) a recovery periodElectronically-braked cycle ergometry witha reasonably constant pedaling frequency(e.g. 60 rpm) is recommended. Essentiallysimilar results are obtained when work rateis either increased continuously (ramp test)or by a uniform small amount at regular shortintervals (e.g. one-minute incremental test)until the patient can no longer sustain thework rate (e.g. he/she cannot cycle > 40 rpm)or is not able to continue safely. Theincrement size should be set according to thephysical capabilities of the subject, to ensurean incremental phase of ~10-12 min; thiscorresponds to an incrementation rate of ~10to 20 W/min for a healthy sedentary subject,but as little as 5 W/min in a patient. However,further modifications to the protocol designof the protocol may be necessary if, forexample, the subject is severely debilitatedor is highly fit. Slower rates of change, inaddition to inducing boredom and seatdiscomfort, also reduce the ability to

"For incremental exercise tests of the"For incremental exercise tests of the"For incremental exercise tests of the"For incremental exercise tests of the"For incremental exercise tests of theramp type, a constant rate of change oframp type, a constant rate of change oframp type, a constant rate of change oframp type, a constant rate of change oframp type, a constant rate of change ofWR replaces the constant absolute WR replaces the constant absolute WR replaces the constant absolute WR replaces the constant absolute WR replaces the constant absolute WR asWR asWR asWR asWR asthe challenge..."the challenge..."the challenge..."the challenge..."the challenge..."

"... the pattern of the VCO"... the pattern of the VCO"... the pattern of the VCO"... the pattern of the VCO"... the pattern of the VCO22222-VO-VO-VO-VO-VO22222 relati- relati- relati- relati- relati-onship is highly dependent upon the rateonship is highly dependent upon the rateonship is highly dependent upon the rateonship is highly dependent upon the rateonship is highly dependent upon the rateat which the at which the at which the at which the at which the WR is incremented..."WR is incremented..."WR is incremented..."WR is incremented..."WR is incremented..."


V'E-V'CO2 relationship and ventilatoryequivalentsThe ventilatory (V'E) response to exercise asa function of V'CO2 is fundamentally relatedto the regulation of arterial PCO2 (PaCO2)and pH.For alveolar ventilation (V'E) the relationshipis:V'A= 863 x VCO2 /PaCO2

Consequently, to regulate PaCO2, V'A mustchange as an appropriate linear function ofV'CO2. However, with respect to total venti-lation (i.e. V'E) the relationship is complicatedby the ventilation of the physiological deadspace or by the dead space fraction of thebreath (VD/VT) such that:V'E= 863 x VCO2 /[PaCO2 (1 - VD/VT)]High values of V'E/V'CO2 therefore reflecteither a low PaCO2, high VD/VT or both. Nat-urally, if one is known or may be plausiblyassumed, then the high V'E/V'CO2 may be in-terpreted in terms of the other.It should be noted, however, that a high VD/VT does not necessarily reflect abnormal pul-monary function, as it is highly dependenton the pattern of breathing: rapid, shallowbreathing, for example, yields a high VD/VTeven in subjects with normal pulmonaryfunction.V'E has been widely demonstrated to changeas a linear function of over a wide range ofWRs, i.e.: V'E = mV'CO2 + cDifferent investigators use different aspectsof these latter equations to characterise theventilatory response:a) the ratio V'E/ V'CO2 andb) DV'E/DV'CO2 (i.e. m).Clearly, V'E/V'CO2 is important, as it is in-fluenced only by VD/VT and PaCO2. Note thatin cases in which PaCO2 is constant, VE/V'CO2 falls in exact proportion to that of VD/VT. Interestingly, the constant m can be defi-ned as:m =V'E /V'CO2 - c/V'CO2

That is, m may be considered to be theasymptote of the decliningV'E/V'CO2-profi-le; not necessarily its lowest value achievedduring the test. Alternatively, V'E/V'CO2 maybe considered to decline during exercise as aresult of the positive intercept c. For rapid-incremental tests, interestingly, the linearityof the V'E-V'CO2 relationship is maintainedbeyond the lactate threshold; i.e. V'E chan-ges in proportion to the total CO2 load, withno evidence of PaCO2 being reduced to pro-vide respiratory compensation (isocapnicbuffering). The respiratory compensationbegins at higher WR, when both V'E/V'CO2and m begin to increase.

Essay

"...a high V"...a high V"...a high V"...a high V"...a high VDDDDD/V/V/V/V/VTTTTT does not necessarily re-does not necessarily re-does not necessarily re-does not necessarily re-does not necessarily re-flect abnormal pulmonary function, as itflect abnormal pulmonary function, as itflect abnormal pulmonary function, as itflect abnormal pulmonary function, as itflect abnormal pulmonary function, as itis highly dependent on the pattern ofis highly dependent on the pattern ofis highly dependent on the pattern ofis highly dependent on the pattern ofis highly dependent on the pattern ofbreathing..."breathing..."breathing..."breathing..."breathing..."

VCO2-VO2 relationshipThe profile of pulmonary CO2 output(V'CO2) as a function of V'O2 during incre-mental exercise is dependent upon two fac-tors:

the substrate mixture undergoing oxida-tion (i.e. the RQ effect) andthe CO2 storage into from muscle andblood (i.e. the factor that causes RER todiffer from RQ).

Consequently, the pattern of the VCO2-VO2-relationship is highly dependent upon the rateat which the WR is incremented.The typical pattern, however, is one in whichthe V'CO2 response initially lags that of V'O2early in the transient and then increases of-ten as a linear function of V'O2. The slopeof the relationship (DV'CO2/DV'O2) in thisregion has been termed S1, with a value typi-cally close to unity in subjects on typicalwestern diet - but can be greater than 1, evenwithout hyperventilation!The slope of the V'CO2-V'O2 relationshipincreases at a particular V'O2 as the aerobi-cally produced CO2 released frombicarbonate buffering of protons associatedwith lactate accumulation. The slope in thishigher WR region has been termed S2, andas the amount of CO2 released in the protonbuffering process is a function not of themagnitude of [bicarbonate] decrease but itsrate of decrease, this slope is highly depen-dent on the WR incrementation rate. Furt-hermore, at slow WR incrementation rates,additional CO2 from compensatory hyperven-tilation supplements the V'CO2 in the S2 ran-ge; this is not the case for rapid incrementa-tion rates, for reasons not fully understood.Maximum RER, being so dependent on theramp slope is consequently not a good indexof subject "effort".The S1-S2 transition reflects a metabolic rateabove which CO2 is released from the bodythat does not originate in either aerobic me-tabolism or hyperventilation. And as bicar-bonate is clearly the origin of this extra CO2,and the [bicarbonate] change is a close pro-portional function of the increase in muscle[lactate], this is considered to be a valid non-invasive index of the lactate (or anaerobic)threshold. When the V-slope plot may not bepartitioned into two defensibly-linear seg-ments the unit tangent to the curve may beused as a second order estimate of the lactatethreshold.

"End-tidal gas tensions are easy to measu-"End-tidal gas tensions are easy to measu-"End-tidal gas tensions are easy to measu-"End-tidal gas tensions are easy to measu-"End-tidal gas tensions are easy to measu-re and extremely difre and extremely difre and extremely difre and extremely difre and extremely difficult to interpret..."ficult to interpret..."ficult to interpret..."ficult to interpret..."ficult to interpret..."

As V'E is so closely linked to V'CO2 and asV'CO2 varies markedly with the WR incre-mentation rate, V'E does not change in a use-fully-constant relationship to V'O2, and henceis rarely used in this context. The ratio V'E/V'O2 however, is used as an index of the ad-ditional ventilatory drive that attends the ac-celerated CO2 output at work rates above thelactate threshold. Having declined throug-hout the moderate work-rate range, V'E/VO2begins to increase reflective of increasedV'CO2, and when coupled with V'E/VO2 notincreasing (i.e. isocapnic buffering) providesgood support that the increased ventilatorydrive is not consequent to hyperventilation -in which case both V'E/V'O2 and V'E/VCO2and the slope of the V'CO2- V'O2 relations-hip increases.End-tidal gas tensionsEnd-tidal gas tensions, i.e. the values deter-mined at the end of an exhalation, are easyto measure and extremely difficult to inter-pret. During exhalation, alveolar PCO2(PACO2) continues to increase at a rate that isdependent on the mixed venous PCO2 valueand to a level that depends on the durationof the exhalation; The end-tidal value beinggreater than the mean alveolar and arterialvalue, as work rate increases in normal sub-jects is therefore entirely to be expected.The end-tidal to mean alveolar PCO2 diffe-rence continues to increase as WR and there-fore increases, but can then stabilise at WRsat which tidal volume ceases to continue toincrease with respect to V'CO2, and breathingfrequency therefore accelerates, progressi-vely to shorten expiratory duration. PETCO2may therefore be considered to be the peakof the oscillation of PACO2 during the brea-thing cycle.In the "ideal" lung, "arterial" blood will alsomanifest such an oscillation, but thisoscillation is not measured: what is measuredis the mean of this oscillation in PaCO2, asblood is sampled over several respiratorycycles. Mean PaCO2, however, differs frommean PACO2 as a result of ventilation-to-perfusion inhomogeneities and/or right-to-left shunt - leading to PETCO2 beingcommonly less than PaCO2 in patients withCOPD for example. Consequently, PETCO2equal to or less than mean PaCO2 duringexercise is reflective of abnormal gasexchange.


End-tidal PCO2 should therefore not be usedto represent arterial PCO2 in computing VD/VT. Doing so overestimates VD/VT in normalsubjects (tending to make abnormal what isnormal) and underestimates it in patients withlung disease (tending to make normal whatis abnormal). Algorithms for estimatingPaCO2 from PETCO2 are poor in normal sub-jects and do not work in subjects with lungdisease.Consequently, the profile of PETCO2 withincreasing WR is normally such that itincreases progressively up to the lactatethreshold, then stabilizes in the region ofisocapnic buffering, and subsequentlydecreases as frank compensatory hyper-ventilation is manifest. In contrast, end-tidalPO2 (PETO2) progressively decreases up to thelactate threshold, after which it increasessystematically, accelerating further with theonset of compensatory hyperventilation.

VO2 heart rate relationship andoxygen pulseThe oxygen pulse, or the stroke extractionof oxygen (V'O2/HR) bears a similar relation-ship to the V'O2/HR-slope as the ventilatoryequivalent for CO2 does with the V'E/V'CO2-Slope. That is, heart rate changes effectivelylinearly as a function of V'O2 with a slopethat is an inverse function a physical fitness.It is instructive to consider the axes diffe-rently however: that is, plotted as functionof heart rate. This relationship has a negati-ve intercept on axis. Consequently, the oxy-gen pulse, which by definition is the absolu-te VO2to heart rate ratio increases hyperbo-lically as work rate increases.But the oxygen pulse is of interest in an ad-ditional sense: it is numerically equivalentto the product of stroke volume and the arte-rio-venous oxygen content difference. It isimportant to point out, however, that it shouldnot be considered a function of either of thesevariables - only the product. Consequently,only if it is possible to make a reasonableassumption regarding the change (or not) ineither of the two defining variables may oneinterpret the non-invasive O2 pulse profileto reflect that of the alternative variable. This,of course, would be both more difficult todetermine directly and would require an in-vasive procedure.

If the O2 pulse fails to increase with increas-ing work rates, then the product of the vari-ables is constant. But this may be becauseeach is constant or one is increasing whilethe other decreases. Flatness in the O2 pulseprofile should be considered with care, ho-wever, as subjects who are normal but unfithave a shallow slope of V'O2 plotted as afunction of heart rate and hence the curvatu-re of the O2 pulse profile will be shallow -appearing to be flat when in fact it is not.For the O2 pulse to be flat there must be achange in the slope such that heart rate acce-lerates relative to such that over this regionthe slope extrapolates back to the origin ofthe plot. When this does occur continued in-crease in is heart rate dependent.

Essay

"Subjects who are normal but unfit have"Subjects who are normal but unfit have"Subjects who are normal but unfit have"Subjects who are normal but unfit have"Subjects who are normal but unfit havea shallow slope of V'Oa shallow slope of V'Oa shallow slope of V'Oa shallow slope of V'Oa shallow slope of V'O22222 plotted as a func-plotted as a func-plotted as a func-plotted as a func-plotted as a func-tion of heart rate..."tion of heart rate..."tion of heart rate..."tion of heart rate..."tion of heart rate..."

ReferReferReferReferReferencesencesencesencesences1. GallagherGallagherGallagherGallagherGallagher, C., C., C., C., C. Exercise and chronic obstructive pulmonary disease. Med. Clinics N. Am. 74:619-

641, 1990.2. Hadebank, D., Reindl, I., Hadebank, D., Reindl, I., Hadebank, D., Reindl, I., Hadebank, D., Reindl, I., Hadebank, D., Reindl, I., VVVVVietzke G., et al. ietzke G., et al. ietzke G., et al. ietzke G., et al. ietzke G., et al. Ventilatory efficiency and exercise tolerance in

101 health volunteers. Eur J Appl Physiol 77:421-426, 1998.3. Johnson, B.D., BadrJohnson, B.D., BadrJohnson, B.D., BadrJohnson, B.D., BadrJohnson, B.D., Badr, M.S., Dempsey, M.S., Dempsey, M.S., Dempsey, M.S., Dempsey, M.S., Dempsey, J.A. , J.A. , J.A. , J.A. , J.A. Impact of the aging pulmonary system on the re-

sponse to exercise. Clin Chest Med 15:229-246, 1994.4. Jones, N.L.Jones, N.L.Jones, N.L.Jones, N.L.Jones, N.L. Exercise testing in pulmonary evaluation: Rationale, methods, and the normal

respiratory response to exercise. New Engl. J. Med. 293:541-544, 1975.5. NederNederNederNederNeder, J.A., L.E. Ner, J.A., L.E. Ner, J.A., L.E. Ner, J.A., L.E. Ner, J.A., L.E. Neryyyyy, C. Per, C. Per, C. Per, C. Per, C. Peres, and B.J. es, and B.J. es, and B.J. es, and B.J. es, and B.J. Whipp.Whipp.Whipp.Whipp.Whipp. Reference values for dynamic responses to

incremental cycle ergometry in males and females aged 20 to 80. Am. J. Respir. Crit. Care Med.164:1481-1486, 2001.

6. Roca, J., Roca, J., Roca, J., Roca, J., Roca, J., Whipp, B.J. (eds): Whipp, B.J. (eds): Whipp, B.J. (eds): Whipp, B.J. (eds): Whipp, B.J. (eds): Clinical Exercise Testing. European Respiratory Monograph vol2, No 6. Sheffield: European Respiratory Journals, 1997.

7. Rowell, L.B., Shepherd, J.TRowell, L.B., Shepherd, J.TRowell, L.B., Shepherd, J.TRowell, L.B., Shepherd, J.TRowell, L.B., Shepherd, J.T. (eds). . (eds). . (eds). . (eds). . (eds). Handbook of Physiology, Sect 12, Exercise: Regulationand Integration of Multiple Systems. New York: Oxford Univ Press, 1996.

8. WWWWWagneragneragneragneragner, P, P, P, P, P.D..D..D..D..D. Determinants of maximal oxygen transport and utilization. Ann Rev Physiol 58:21-50, 1996.

9. WWWWWasserman, K., Hansen, J.E., Sue, D.Yasserman, K., Hansen, J.E., Sue, D.Yasserman, K., Hansen, J.E., Sue, D.Yasserman, K., Hansen, J.E., Sue, D.Yasserman, K., Hansen, J.E., Sue, D.Y., Casaburi, R, ., Casaburi, R, ., Casaburi, R, ., Casaburi, R, ., Casaburi, R, Whipp, B.J.Whipp, B.J.Whipp, B.J.Whipp, B.J.Whipp, B.J. Principles of exercisetesting and interpretation. Philadelphia, Lippincott, Williams & Wilkins, 1999.

10. WWWWWeisman, M., Zeballos, R.J.eisman, M., Zeballos, R.J.eisman, M., Zeballos, R.J.eisman, M., Zeballos, R.J.eisman, M., Zeballos, R.J. Clinics in Chest Medicine. Saunders, 1994.

"In the "ideal" lung, arterial blood will"In the "ideal" lung, arterial blood will"In the "ideal" lung, arterial blood will"In the "ideal" lung, arterial blood will"In the "ideal" lung, arterial blood willalso manifest such an oscillation, but thisalso manifest such an oscillation, but thisalso manifest such an oscillation, but thisalso manifest such an oscillation, but thisalso manifest such an oscillation, but thisoscillation is not measured..."oscillation is not measured..."oscillation is not measured..."oscillation is not measured..."oscillation is not measured..."

"...the oxygen pulse, which by definition"...the oxygen pulse, which by definition"...the oxygen pulse, which by definition"...the oxygen pulse, which by definition"...the oxygen pulse, which by definitionis the absolute VOis the absolute VOis the absolute VOis the absolute VOis the absolute VO2 2 2 2 2 heart rate ratio, incre-heart rate ratio, incre-heart rate ratio, incre-heart rate ratio, incre-heart rate ratio, incre-ases hyperbolically as work rate increa-ases hyperbolically as work rate increa-ases hyperbolically as work rate increa-ases hyperbolically as work rate increa-ases hyperbolically as work rate increa-ses..."ses..."ses..."ses..."ses..."

considered to represent the subjectísbreathing reserve (BR). The breathing reservecan be zero (or even less than zero, forexample, in a subject who bronchodilatesduring exercise) either as a result of the MVVbeing low, as in patients with lung disease,or in normal but highly fit subjects who canachieve high rates of metabolic rate andhence of ventilation. Similarly if themaximum expiratory airflow produced witha maximum expiratory effort is consideredto reflect the greatest possible flow at aparticular lung volume (this of course is notnecessarily the case in subjects withobstructive lung disease) then failure toachieve these flows on a breath duringexercise is reflective of flow reserve.Similarly, a tidal volume that encroachesupon the inspiratory capacity is reflective oflack of volume reserve. Whether a subjecthas significant heart rate reserve at maximumexercise is usually judged in the light of theexpected maximum value for a subject of thatage - unfortunately, the variability of thisexpected age-dependent maximum heart rateis very wide.

8. 8. 8. 8. 8. VVVVValues attained at the limits ofalues attained at the limits ofalues attained at the limits ofalues attained at the limits ofalues attained at the limits oftolerancetolerancetolerancetolerancetoleranceWhen a subject has ostensibly exercised tothe limit of tolerance it is useful to discernwhether certain features of the systems thatcontribute to the energy exchange havereached their limit. Naturally to make thisjudgement it is necessary to have an indexof what that limit is. For example, if the MVVdetermined at rest is considered to be themaximum ventilation attainable then thedifference between this and the value actuallyattained at the end of exercise can be


Definition: Cardiopulmonaryexercise testing is defined as thecontinuous measurement of respi-ratory gases during exercise.

During cardiopulmonary exercise testing thesubject is placed either on an ergometric bi-cycle or treadmill where load can be contin-uously increased.The complex requirements of cardiopulmo-nary exercise testing are met by ramp proto-cols. During this type of test, strain is in-creased in small increments. The duration ofthe test should be between 8 to 12 minutes.For a complete analysis of respiratory func-tion, the flow-volume curve should be re-corded at rest, prior to exercise and duringsubmaximal and maximal exercise. The sameapplies to blood gas values and P(A-a)O2.To clarify special questions concerning gasexchange (for example diffusion disorders),a constant workload test below anaerobicthreshold including blood gas analysis maybe performed.Exercise should be symptom-optimized,whereby the usual termination criteria forexercise tests have to be observed.

CPET - VCPET - VCPET - VCPET - VCPET - Various Fields of Applicationarious Fields of Applicationarious Fields of Applicationarious Fields of Applicationarious Fields of ApplicationIndication and relevance of cardiopulmonaryexercise testing

Kardiologie

Estimated oxygen uptake during differentEstimated oxygen uptake during differentEstimated oxygen uptake during differentEstimated oxygen uptake during differentEstimated oxygen uptake during differentactivities and occupations:activities and occupations:activities and occupations:activities and occupations:activities and occupations:

[ml/kg/min]

Work, sitting 4,25Driving a car 4,25Driving a truck 5,30Work, standing 8,75Walking (4.5 km/h) 10,50Crane operating 8,75Cleaning the floor 9,45Light warehouse work 10,50Painting, wall paper hanging 14,00Bricklaying, carpentry 14,00 - 21,00Working with Jack hammer 21,00Steel worker 27,00

FourFourFourFourFour basic parameters will be r basic parameters will be r basic parameters will be r basic parameters will be r basic parameters will be recordedecordedecordedecordedecordedwith the help of a brwith the help of a brwith the help of a brwith the help of a brwith the help of a breathing mask andeathing mask andeathing mask andeathing mask andeathing mask andECG electrECG electrECG electrECG electrECG electrodes:odes:odes:odes:odes:

Minute ventilationOxygen uptakeCarbon dioxide outputHeart rate (stress ECG)

Prior to CPET the following should bePrior to CPET the following should bePrior to CPET the following should bePrior to CPET the following should bePrior to CPET the following should becompleted:completed:completed:completed:completed:

Patient historyECG at restPulmonary function test

Pulmonology

Cardiology

Sports medicine

Occupational medicine

Intensive care

Rehabilitation

If exercise capacity is limited, the character-istic patterns of the parameters provide im-portant information about which organs areaffected by the impairment.As testing sytems become more and moreuser-friendly, the interest in comprehensivecardiopulmonary exercise testing is contin-uously increasing. Due to the variety of pa-rameters provided, the fields of applicationare widely distributed.If an organ or an organic system is impaired,the subjects' ability to adjust to increasingstrain is impaired.

Applications

IntrIntrIntrIntrIntroductionoductionoductionoductionoductionCPET is a diagnostic procedure that analyz-es the response and cooperation of the heart,circulation, respiration and metabolism dur-ing continuously increasing muscular strain.In this way, maximum exercise capacity andthe endurance capacity threshold can be de-tected. These parameters are of special im-portance in the fields of:


During CPET the following paramters canDuring CPET the following paramters canDuring CPET the following paramters canDuring CPET the following paramters canDuring CPET the following paramters canbe rbe rbe rbe rbe recorded:ecorded:ecorded:ecorded:ecorded:

Maximum oxygen uptake (peak VO2)Oxygen uptake at anaerobic threshold(VO2AT)Oxygen pulse (O2 Pulse)Breathing equivalents (EQO2, EQCO2)Dead space ventilation (VD/VT)Aerobic capacity (dVO2/dWR)Alveolar-arterial oygen pressure diffe-rence (P(A-a)O2)Respiratory exchange ratio (RER)Work rate (watts)Heart rate reserve (HRR)Breathing reserve (BR)

Applications of CPET

Curve analysisCurve analysisCurve analysisCurve analysisCurve analysisIn addition to the assessment of the achievedmaximum values, the curve trends of the in-dividual parameters have to be assessed overthe entire exercise test. Modern CPET sys-tems with breath by breath analysis (such asthe Jaeger Oxycon series) allow for a highresolution of the individual parameters. Onthe basis of the nine panel graph, deviationsof the expected curve trend can be easily as-sessed. Depending on the limiting clinicalpicture, typical changes are to be expected.On-line recording of the flow-volume curvesduring exercise is also very helpful. By su-perimposing the maximal envelope and thecurrent flow curve, the impairment is re-vealed in the form of a volume or flow limi-tation.

DocumentationDocumentationDocumentationDocumentationDocumentationComprehensive and reproducible documen-tation of the exercise test is indispensable.Test type and load protocol, as well as anassessment of the achieved capacity accord-ing to clinical criteria, should be document-ed independently of the achieved measuredvalues. At the end of the test the subjectshould be interviewed on the basis of theBorg scale. This simplifies interpretation ofexamination results, especially if measuredvalues suddenly differ greatly.

Fig. left:9-panel graph

Fig. right:Intrabreath

Application

PPPPPneumologyneumologyneumologyneumologyneumology

Obstructive and restrictive ventila-tory disordersInterstitial disordersPulmonary hypertensionDiffusion and distributiondisordersFlow disordersStress dyspnea of unknowncauseSuspected limited exercise capa-city due to circulatory or pulmona-ry disordersSuspected exercise-induced asth-maTrend control in presence of re-spiratory and pulmonary diseasesRisk estimation for lung transplantpatients

CardiologyCardiologyCardiologyCardiologyCardiology

Coronary heart diseaseCardiomyopathyValvular heart diseaseCongenital cardiac defectsRisk estimation for heart trans-plant patientsCardiac insufficiency

Sports MedicineSports MedicineSports MedicineSports MedicineSports Medicine

Measurement of physical perfor-mance for effective training adjus-tmentQuantification of an increase inperformance

Occupational MedicineOccupational MedicineOccupational MedicineOccupational MedicineOccupational Medicine

Determination of occupationalexercise toleranceDetermining the degree of disabi-lity or work limitation/inabilityFitness checkups (high altitude,air travel, tropical climate, diving)

Intensive CareIntensive CareIntensive CareIntensive CareIntensive Care

Risk assessment prior tosurgeryNutrition control (adjusting paren-teral nutrition of intensive carepatients)

RRRRRehabilitationehabilitationehabilitationehabilitationehabilitation

To optimize rehabilitative mea-suresTo assess and document rehabili-tative and therapeutic progress


Oxycon POxycon POxycon POxycon POxycon Pro - CPET of the Highest Qualityro - CPET of the Highest Qualityro - CPET of the Highest Qualityro - CPET of the Highest Qualityro - CPET of the Highest Quality

Oxycon Pro is the perfect solution for routinecardiopulmonary exercise testing. The smallhandy unit combines everything required forroutine examinations and offers unparalleledease of operation. And as costs are an impor-tant factor in modern day medicine, OxyconPro is favorably priced and meets the highestquality standards. The modular concept pro-vides sufficient possibilities for upgrades orsubsequent expansion, whenever required oryour investment policies allow it.The heartheartheartheartheart of the Oxycon Pro is its preciseand reliable ergospirometry measurement pro-gram. Ergospirometry and related parameterscan either be measured "Breath by Breath","Intrabreath" or via the mixing chamber.User-specific work load protocols for exer-cise on bicycle or treadmill guide you throughthe test. The screen display is clearly struc-tured. Preset and logically arranged graphsand groups of graphs show the status of thecurrent workload phase with predicted/actualvalue comparison.

A modern diagnostic system must not only be techni-cally convincing, it must above all, be tailored to theroutine clinical needs. Therefore, we made OxyconPro even faster, more precise and above all, evenmore economic. For your daily routine you need apractical tool which is suitable for its tasks. After all,you prefer to give attention to your patients and not toyour equipment. That is why Jaeger developed theOxycon Pro.

Oxycon is your expert system if you need afavorably priced CPET system including ECGrecording at rest and during exercise.Oxycon Pro precisely analyzes, differentiatesand quantifies the functional cooperation ofheart, lungs, circulation and metabolism.Oxycon Pro is a secure investment for physi-cians working in the fields of cardiology, oc-cupational medicine, pediatrics, pulmonologyand intensive care. It is the ideal system forthe secure assessment of physical perfor-mance.

Integrated PC-based ECG:Integrated PC-based ECG:Integrated PC-based ECG:Integrated PC-based ECG:Integrated PC-based ECG:All data at a glance:All data at a glance:All data at a glance:All data at a glance:All data at a glance:

A notable feature of Oxycon Pro is the ex-ceptional stability of the stress ECG baselinetraces. 12-channel ST monitoring is based ona 10-second-interval. A clearly structured STgraph displays the ST changes in differentcolor. In addition, automatic arrythmia detec-tion is provided.

Fig. above: 12-channel ECG including ergospirometry data

Diagnostics


Ergospirometry data during testing - clear and easy

The advantages of Oxycon PrThe advantages of Oxycon PrThe advantages of Oxycon PrThe advantages of Oxycon PrThe advantages of Oxycon Pro:o:o:o:o:

Windows-based user interfaceAutomatic calibration programsFast and highly precise gas analyzersPrecise, low-resistance volume sensor,no flow limitation in the physiologicalrangeStandard measurement programs:

Spirometry/Flow-VolumeBreath by Breath, Intrabreath(partial Flow-Volume loop)Indirect calorimetryIntegrated, optional paper-free12 channel ECG

Interpretation programÑIntelliSupportìInformative, detailed reportsAll components available fromJAEGERModular conceptInterfaces for stress-testing devicesand other systems, for example,external ECGData management for practiceadministration systems and forhospital networks

Oxycon Pro

Oxycon Pro on trolley

Diagnostics

Oxycon ProOxycon ProOxycon ProOxycon ProOxycon Pro

O2/CO2-analyzerDigital volume sensor (TripleV)Pentium PCInk-jet printerTrolley

Standard programs:Standard programs:Standard programs:Standard programs:Standard programs:Patient dataAutomatic volume calibrationVolume calibration via manual cal. pumpAutomatic gas analyzer calibrationAmbient conditionsSpirometry/Flow-VolumeOff-line blood gases/lactateBreath by BreathIntrabreathMixing chamberHigh/Low FiO2Indirect calorimetry- Hood- Ventilator- Hood with high FiO2- Hood for childrenCardiac outputCompliance during exerciseP0.1 during exerciseResting and stress ECGScreen and printer reportInterpretation program:Interpretation program:Interpretation program:Interpretation program:Interpretation program:IntelliSupportGeneration programs:Generation programs:Generation programs:Generation programs:Generation programs:ReportDesignerLayout editorProfile editorParameter text editorLaguageMakerUser predicted valuesPredicted value generationOther programs:Other programs:Other programs:Other programs:Other programs:Data baseLoad controlConnection to practice/hospital EDP syst.ECG suction devicePulse oximeter

StandardOption


product as well as pyruvate and lactate as ananaerobic intermediate product.Thanks to cardiopulmonary exercise testing,it is possible to quantify a subject's oxygenuptake (VíO2) and carbon dioxide release(VíCO2) and can indirectly observe vesicu-lar breathing in humans and consequentlycellular respiration.Due to adequate ventilation (VíE), the brea-thing mechanism allows for gas exchange(VíO2 and VíCO2) which provides the mus-cles with oxygen (DíO2) and assures that car-bon dioxide be transported off (DíCO2)bridged by the cardiovascular system (car-diac output). Coupling the processes of cel-lular respiration, the cardiovascular systemand ventilation are regulated as required ac-cording to the blood- and tissue-homeosta-sis rules for pH, oxygen and carbon dioxidecontent by central and peripheral regulatorymechanisms. These control mechanisms areresponsible for the interaction between thesethree systems so that the increasing metabo-lic requirements in the cells under stress canbe met. Sufficient oxygen flow to the cellsand blood gas homeostasis (pH) in increa-sed carbon dioxide generation through phy-sical activity are regulated as needed. If oneof the systems is disturbed (peripheral, car-diovascular, pulmonary or central regula-tion), considerable changes occur which canbe quantified during cardiopulmonary exer-cise testing.

As we will later see, the test results are high-ly reproducible. Consequently, this methodis especially suited:

1. to determine the severity of a perforseverity of a perforseverity of a perforseverity of a perforseverity of a perfor-----mance limitation with rmance limitation with rmance limitation with rmance limitation with rmance limitation with respect to respect to respect to respect to respect to repreprepreprepro-o-o-o-o-ducibility ducibility ducibility ducibility ducibility (for approaches in cardiology,pulmonology and assessments)

2. to define the efthe efthe efthe efthe effect of therapeutic interfect of therapeutic interfect of therapeutic interfect of therapeutic interfect of therapeutic inter-----ventions ventions ventions ventions ventions in the presence of exercise limi-tation

3. to provide suppor suppor suppor suppor support in dift in dift in dift in dift in differferferferferential diag-ential diag-ential diag-ential diag-ential diag-nosis nosis nosis nosis nosis regarding the cause of exercise li-mitation (cardiac, pulmonary or periphe-ral).

Indications for peforming cardiopulmona-Indications for peforming cardiopulmona-Indications for peforming cardiopulmona-Indications for peforming cardiopulmona-Indications for peforming cardiopulmona-rrrrry exery exery exery exery exercise testing (Tcise testing (Tcise testing (Tcise testing (Tcise testing (Tab. 1)ab. 1)ab. 1)ab. 1)ab. 1)Sports medicineAs cardiopulmonary exercise testing mea-sures a subject's exercise capacity, it is oftenused to examine healthy subjects in the fieldof sports medicine. In contrast to the stressECG, which is somewhat simpler, cardiopul-monary exercise testing allows for the ob-jective and non-invasive measurement of asubject's cardiorespiratory performance andof an athlete's anaerobic threshold. The re-sults provide important information for train-ing purposes. This method has been appliedfor years (9) and is a routine measurement insports medicine (10).

Cardiopulmonary Exercise TCardiopulmonary Exercise TCardiopulmonary Exercise TCardiopulmonary Exercise TCardiopulmonary Exercise TestingestingestingestingestingAuthor: Author: Author: Author: Author: WWWWW. Mitlehner M.D.. Mitlehner M.D.. Mitlehner M.D.. Mitlehner M.D.. Mitlehner M.D.

Authorized translation from GermanAuthorized translation from GermanAuthorized translation from GermanAuthorized translation from GermanAuthorized translation from German

Exercise testing and ECG recording have been known for about 60 years (1, 2) and have meanwhile beenstandardized. The goal of this routine test is to detect coronary heart disease. More than 70 years ago, A.V.Hill was the first researcher to examine gas exchange and acid-base-metabolism during exercise whilestudying muscular physiology (3). During the 1940's, a precise method for testing gas exchange (oxygenuptake and carbon dioxide release) was established for the first time by P.F. Scholander (4). During the1950's, cardiopulmonary exercise testing had been applied in clinical examinations of patients with cardiacdiseases (5, 6). A non-invasive stress testing procedure was hence established that allowed recording ofcardio-circulatory and ventilatory, as well as "peripheral" parameters during exercise in addition to elec-trocardiographic changes. However, a great deal of experimental methods were required making the proce-dure not clinically feasible. It were Issekutz and Rohdahl, (7) as well as Wasserman et al., (8) who finallydeveloped a method to reliably record oxygen uptake (V'O2) and carbon dioxide release (V'CO2) with thehelp of fast gas analyzers on a breath-by-breath basis.

IntrIntrIntrIntrIntroduction to CPEToduction to CPEToduction to CPEToduction to CPEToduction to CPETComputer technology and advancement ofthe methods introduced more than 20 yearsago have made it possible to easily performreliable exercise tests, especially in the fieldof cardiology and pneumolgy. The increasinginterest in this procedure caused us to com-pile a practical and comprehensible introduc-tion to CPET in healthy subjects and patientswith lung disease. Literature references canbe found at the end of this brochure.Cardiopulmonary exercise testing can be de-fined as "performance testing on the basisof cardiac, circulatory and ventilatory para-meters" for non-invasive quantification of asubject's physical training limits.In addition to determining a subject's exer-cise capacity (e.g. sports medicine) the testgoals are to record the cause of a possibleperformance impairment and to measure theeffect of therapeutic interventions.Metabolic processes and life are only pos-sible if energy is provided in the body cells.At rest, this process takes place in the musc-le cells where primarily glucose undergoesaerobic metabolic processes in order to formphosphates that are rich in energy (ATP).During physical strain (under stress) ATP isfirst formed aerobically. If stress increases,ATP is increasingly produced anaerobicallyby glycolysis. This process, which is knownas cellular respiration, requires oxygen andsubstrates that are rich in energy (primarilyglucose) and forms carbon dioxide as a final

Practical Guideline


CardiologyIn order to test the cardiorespiratory func-tion in patient groups with cardiac diseases,cardiopulmonary exercise testing is regardedto be the best suited test (11) and should beroutinely performed in transplant patients(11) to determine the severity of the limitati-on and to give evidence of the failure of othertherapeutic interventions.In patients with etiologically undefined stressdyspnea, the test is extremely useful for dif-ferentiating dyspnea with primarily pulmo-nary cause from dyspnea with primarily car-diac cause (12, 13, 14).

PulomonologyIn the presence of restrictive and obstructiveventilatory disorders and their differentcauses, cardiorespiratory exercise testing issuitable for characterizing the resultingcauses, such as limitation of breathing me-chanics, peripheral deconditioning, gas ex-change disorders and stress hypoxaemia. Si-milarily, it is possible to objectively quan-tify the effect of pharmocologic interventionsin both groups of patients as well as the suita-bility of oxygen application (15, 16).Last but not least, exercise testing is usefulin selecting patients for lung transplantationand post-surgical rehabilitation (17).

the patient exercise to a maximum?") and anobjective measurement of his/her exercise ca-pacity as well as the causes of a possible li-mitation.For both cardiological and pneumological as-sessments specific scales are provided clas-sifying the degree of limitation which arebased on cardiopulmonary exercise testing(21, 22).

Rare approachesCardiopulmonary exercise testing has beenused to assess muscular diseases, neuromus-cular diseases and hemoglobinopathy. Therank of CPET, here, is not clearly defined.

Approach Application Value

Performance testing Sports medicine, ADisability evaluations, Cardiology APneumology AMuscular and Neuromuscular Diseases C

Training recommendations Rehabilitation AUndefined dyspnea Cardiology, Pneumology A

Disability Assessments ATransplantation Cardiology, Pneumology ATherapeutical intervention CMP, Cardiac Valve Defects, A

Oxygen Therapy, AInterstitial Pulmonary Disease, ARehabilitation A

Resection of lung tissue Pneumology BCoronary heart disease Cardiology CCHD - ischemic left ventr. insuff. Cardiology APulmonary vascular disease Cardiology, Pneumology B

Cardiac patients with therapeutic interven-tions, the effect of which can be proved byan increased performance, should always beexamined with the help of cardiopulmonaryexercise testing in order to get an objectiveassessment (e.g. therapeutic interventions inthe presence of cardiomoyopathy, mitralvalve defects, pre and post heart transplan-tations).In the field of rehabilitation of patients withcardiac diseases, the test is suitable for defin-ing an adequate training program and objec-tively assessing the effects of training (11).Generally, the test can be used for routinetesting in cardiology, when performance ca-pability is to be tested (11).

In pre-surgical examinations (resection oflung tissue) exercise testing is suitable forexcluding post-surgical complications (18,19).

Cardiology and PulmonologyExercise testing allows the observation ofcardiopulmonary interaction and is thereforeindispensable in defining the dominant cau-se of undefined stress dyspnea (20, 11).

Disability evaluationsFor disability evaluation, cardiopulmonaryexercise testing is of great importance. Incontrast to simple stress testing and "Oxyer-gometry" cardiopulmonary exercise testingprovides both a score of the test quality (did

Table 1: Indications for CPET

Value:A = highly informativeB = informativeC = less informative

In a nutshell, we can say that cardiopulmo-nary exercise testing can be used in manyinternal medical fields. Among many knownmethods, CPET is the most comprehensiveand most informative non-invasive methodand is likely to become the standard methodof routine exercise testing in the field of in-ternal medicine.

Practical Guideline

"The physiological processes during exer-"The physiological processes during exer-"The physiological processes during exer-"The physiological processes during exer-"The physiological processes during exer-cise are quite complex and of inter-cise are quite complex and of inter-cise are quite complex and of inter-cise are quite complex and of inter-cise are quite complex and of inter-disciplinary characterdisciplinary characterdisciplinary characterdisciplinary characterdisciplinary character..."..."..."..."..."


ATP consumption is regenerated by fourphysiological mechanisms:

aerobic respiratory chain phosphoryla-tionanaerobic glycolysiscreatine kinasisadenylate kinasis

On the basis of their myofibrillar ATPase ac-tivity, the voluntarvoluntarvoluntarvoluntarvoluntary muscles y muscles y muscles y muscles y muscles can be diffe-rentiated histochemically in different meta-bolic and functional fiber portions: Type I,IIa, II b and IIx fibers.

Type I fibers are especially rich in oxidativeenzymes, whereas type IIb fibers containmainly glycolytic enzymes.

Practical Guideline

Fig. 1

Fig. 2

Under incremental exercise, recruitment ofthe fibers takes place as follows: S fibers withexercise onset, next cascade-like FR and FIand finally FF.

RC

Physiological BasicsPhysiological BasicsPhysiological BasicsPhysiological BasicsPhysiological BasicsThe physiological processes during exerciseare quite complex and of interdisciplinarycharacter and can only be summarized in avery simplistic form. The author explicitlyrefers to the respective literature (e.g. 12, 23- 25, 31).Physical exercise is physical work (= Powerx Distance = 1 kp x m). This work ismeasured in terms of performance quantities(Performance = Work/Time unit = 1 kpm/min). Physiological performance is traditio-nally given in watts (1 watt = 6,12 kpm/min).For muscle contraction during exercise, ad-ditional energy above basal metabolic ratemust be provided by the metabolism.The increased metabolic requirements aremet by increased fat or carbohydrate oxida-tion (cellular respiration). The energy re-leased by combustion can be defined in termsof kilocalories (oxidation of 1 g fatty acid =9 kcal; oxidation of 1 g carbohydrate = 4kcal).The increased oxygen demands during workare met by external respiration (gas ex-change) and by the cardiovascular system(oxygen transportation). In the case of purecarbohydrate combustion, the physiologicaldemands for oxygen can be calculated as fol-lows: one liter O2 is required for generating5,1 kcal (4,6 kcal in case of fatty acid oxi-dation). Consequently, 1 l oxygen can pro-duce an average of 5 kcal.The carbon dioxide and bicarbonate (CO2,HCO3), which is simultaneously released dur-ing substrate combustion, considerably in-fluence the pH value of the blood and arereleased into the environment via the cardi-ovascular system (carbon dioxide transport)and via external respiration (gas exchange).The physiological demands, i.e. maintenanceof a sufficient oxygenation of the tissue aswell as a physiologically tolerable pH valuein the blood serum are met by a precise hu-moral and neuromechanical regulation me-chanism. This sets the varying parameters (re-spiration, circulation, metabolism) byhomeostasis as required at rest and duringexercise.

Cellular respiration and muscularbioenergeticsMuscle contraction and its power are basedon the interaction of the contractile proteinsactin and myosin. This energy-consumingprocess is made possible by hydrolytic sepa-ration of phosphate from ATP molecules.

Depending on their contractional and fatigue-induced behaviour, muscle fibers and rela-ted motoneurons can be physiologically dif-ferentiated in S (= slow-fatigue-resistant), FR(= fast-fatigue-resistant), FI = (fast-fatigue-intermediate) and FF (= fast fatigable) mo-tor units.These motor units are closely related to his-tochemical classification: the aerobic type Ifibers are slow and fatigue-resistant (S),whereas the anaerobic type IIb fibers are fastfatigable (FF). Types IIa and IIx are of inter-mediate character.


At a load range, which physiologically isbetween 40% and 65% of the individuallyachievable maximal O2 uptake (VíO2 max.),

course of the VíCO2 and VíO2 slope untilAT was reached and beyond AT followed thecourse of the VíCO2 curve, changes againand may show a steeper slope than VíCO2.This is called the "Respiratory CompensationPoint" and shows that tissue acidosis is in-creasing (as a result of muscle fatigue). Theanaerobic threshold and the "RespiratoryCompensation Point" can also be calculatedon the basis of the respiratory equivalentsof O2 (EQO2 = VíE/VíO2) and CO2 (EQCO2= VíE/VíCO2). Please refer to Fig. 4.A permanent increase of EQO2 during exer-cise reflects the anaerobic threshold, whe-reas the rise in EQCO2 beyond AT reflectsthe "Respiratory Compensation Point" (Fig.4).The neural and humoral regulation mecha-nisms, which influence the ventilatory adjust-ment to ventilation, are very complex and yetnot completely known. They cannot bediscussed in the frame of this essay (also com-pare 25).

Respiratory mechanics during exerciseEffective ventilation (VíE in l/min) is deter-mined by tidal breathing (VT in ml) and brea-thing frequency (BF in breaths/min). Duringexercise both parameters will increase inhealthy subjects. At a low work rate, VT ri-ses first (up to approximately 50% of VC).Next, VT and BF will increase similarly. Atapproximately 70 - 80% of VíO2 max BF cangenerally only be increased.The dominant increase of VT during the on-set of exercise is a result of a continuous de-cline in the endexpiratory reserve volume andan increase in the endinspiratory pulmonaryvolume. Especially the endexpiratory declinein pulmonary volume during exercise opti-mizes the power/length ratio of the respira-tory muscles (26).At higher work rates, the increase in brea-thing frequency is characterized by a declinedexpiration time (t E) and an increased inspi-ration time (t I), i.e. ( ti / t TOT > 0.4 - 0.55)(25). The breathing frequencies achieved du-ring exercise are between 50 - 60/min (23).In healthy subjects, the airway resistancechanges during exercise as a result of bron-chodilation, which can be due to a decline invagal stimulation (27), an increase in sym-pathic afference or a release of NO (28).Despite bronchodilation, the increase in VTduring exercise gives rise to an increase inrespiratory work as elastic respiratory workincreases (thoracic expansion, expansion ofthe lung tissue). Additional factors for an in-crease in resistance at rising VT are the in-creasing flow turbulances as well as dyna-mic airway compression, which also occursin healthy subjects.

CO2 production has a greater slope than O2-consumption as aerobic processes of energyproduction are increased due to recruitmentof IIa and IIb fibers. Consequently, the pro-duction of lactate and H-ions rises and CO2even rises by four times the normal amount.In order to counteract the resulting tissue aci-dosis, ventilation is stimulated unproportio-nally to the previously increased O2 demandvia chemoreceptors. During exercise, thisgives rise to an unproportional increase ofventilation (VíE/VíO2) in the presence ofan increasing respiratory exchange rate (RER= VíCO2/VíO2).This ventilatory adjustment to anaerobicmetabolic conditions, i.e. the unproportionalrise of the ventilatory equivalent for oxygen(VíE/VíO2) under exercise is termed as "an-aerobic threshold" (ATan). The simultaneousunproportionate CO2 production and release(VíCO2) can be illustrated by the steeper slo-pe of the VíCO2 curve as compared to theVíO2 curve under increasing load. In thisway, the anaerobic threshold (ATan) can beconstructed geometrically from the curvetrends of VíO2 and VíCO2. This threshold isat 40 - 60% of VíO2 max. Consequently,RER, which under exercise decreased to va-lues < 0.8, will again increase.When exercise is continued, H-ions are in-creasingly produced beyond aerobic thresh-old, which give rise to a further central sti-mulation of ventilation exceeding the alrea-dy high VíCO2-dependent increase. Here, atapproximately 70 - 90% of VíO2 max, theslope of the VíE-curve, which followed the

Practical Guideline

Fig. 3

fibers) are an explanation for the predomi-nant aerobic processes during onset of in-cremental exercise as compared to the pre-dominant anaerobic processes (type IIb fi-bers - FF fibers) at the end of exercise. The-se mainly work glycolytically and under in-creased lactate production, but each havinga higher contractility (FR FI FF fi-bers).At rest and with the onset of exercise, mus-cular energy (ATP) is yielded from glucoseand fat under aerobic conditions. Withincreasing work rate and on the basis of acontinuoulsy increasing O2 demand a relati-ve O2-deficiency occurs in the tissue in ad-dition to ATP regeneration giving rise to anincrease in anaerobic processes (involvingthe already mentioned fiber types FR, FI, FF),which form less ATP, but more lactate andH+ions as well as CO2.Under the anaerobic conditions of muscularmetabolism, CO2 forming is four times highergiving rise to an increasing acidosis. Simul-taneously, increasing lactate production du-ring anaerobic glycolysis and increasing tis-sue acidosis result in an unproportional risein ventilation or ventilatory demand (anae-robic threshold) during exercise (Fig. 1, 2,3).With steadily increasing exercise, muscle fi-bers are increasingly recruited and blood sup-ply and consequently O2 supply to the mus-cles continuously increase. Simultaneously,CO2 production in the muscles rises as a li-near function.

The load-dependent recruitment of differenttypes of fibers and consequent different me-tabolic pathways (type I fibers type IIb


An increased ventilation during exercisegives rise to an increased O2 demand of therespiratory muscles (VíO2 resp.). At rest andwith moderate work rate, the share of VíO2resp. of total VíO2 is reported to be approxi-mately 5% (29, 30). In healthy athletes, thisshare can increase to 7% up to a maximumof 15 - 20% of VíO2.Breathing reserve (BR) is defined to be thedifference between maximum voluntary ven-tilation (MVV) and maximum ventilationduring exercise (VíE max):BR = MVVBR = MVVBR = MVVBR = MVVBR = MVV - - - - - VíEmax.VíEmax.VíEmax.VíEmax.VíEmax.Healthy subjects terminate the test with apeak ventilation not exceeding 50 - 70% ofMVV. This is due to the fact that VT normal-ly reaches only approximately 50 - 60% ofVC during exercise (31). Similarily, the ma-ximum breathing frequencies achievable atrest cannot be reached during exercise. Con-sequently, these persons have a breathing re-serve. However, top athletes utilize theirbreathing frequency up to their breathing me-chanism limit.

During expiration the mixed expiratory CO2pressure (PECO2) and the endexpiratory CO2pressure (PET-CO2) can be measured.Analogous measurements are responsible forthe expiratory/inspiratory O2.The PECO2 is defined by a gas mixture,which is determined by dead space (anato-mical and physiological dead space) and al-veolar ventilation. The parts of the lung withdifferent VíA/Q relation are responsible forthe composition of the gas mixture.Therefore, the relation between arterial bloodgases and composition of mixed expiratorygas concentrations are an index for the ef-fectivity of gas exchange.Physiological dead space (VD/VT) is calcu-lated as follows:

VD/VT = (PaCOVD/VT = (PaCOVD/VT = (PaCOVD/VT = (PaCOVD/VT = (PaCO22222 - PECO - PECO - PECO - PECO - PECO22222)/PaCO)/PaCO)/PaCO)/PaCO)/PaCO22222

As physiological dead space is an importantvariable for gas exchange, a change in itsshare can considerably contribute to the ad-justment to the higher ventilatory demandduring exercise.

Practical Guideline

At rest, dead space ventilation (VD/VT) is >30% and considerably declines in healthysubjects (far below 20%). If, during deadspace ventilation measurement, PETCO2 ismeasured instead of PaCO2, dead space ven-tilation is overestimated in normal subjectsand underestimated in patients with lung di-sease. That's why many evaluation programsallow the entry of the arterial PaCO2 as a cor-rection factor for dead space calculation.Oxygen saturation which during exercise ismainly measured as PaO2, is kept in the rangeof the values measured at rest in healthy sub-jects.

Fig.4

Gas exchangeAlveolar ventilation (VíA) and perialveolar-acinic perfusion (Q) are the determinants ofgas exchange.The balance between VíA and Q (VíA/Q)defines the effectivity of gas exchange of acertain alveolar region in the lung. Under cer-tain conditions (physiological rest) there areregions of different VíA/Q sections, e.g. independant parts of the lung, perfusion ishigher than ventilation. Consequently, alve-olar O2 pressure (PAO2) is lower and CO2pressure (PACO2) is higher than in regionsof lower perfusion as compared to ventilati-on.

It should, however, be noted that with capil-lary PaO2 measurement, the arterial PaO2 val-ues are not always correct (32). Additional-ly, it should be pointed out that the precisionof blood gas analyzers can vary (33), so thatonly changes of values > 5 mmHg should beconsidered. Yet, despite these technicalmeasurement problems, certain deviationsfrom the initial PaO2 under load (up to < 70mmHg) are experienced while testing healthypatients (older patients, competitive athletes)under physiological conditions.Both alveolar and arterial O2 pressures willdiscretely change during exercise (Fig. 5).Furthermore, alveolar-arterial pressure dif-ference rises. At rest, the value is approxi-mately 8 mmHg (30) and can amount up to40 mmHg in top athletes (31). The cause forthe increase of this difference is thought tobe a limitation of O2 diffusion and an incre-ase in V'A/Q mismatch (31).

Cardiovascular responseSystemic oxygen transportation to the work-ing muscles depends on the blood supply ofthe tissue (Cardiac Output) and on the oxy-gen contents of the arterial blood (= arterialO2 pressure + contents of hemoglobin + O2to hemoglobin affinity). The increased oxy-gen transportation during exercise is prima-rily achieved by increasing cardiac output.With increasing work rate, oxygen uptakeand cardiac output will increase in a linearrelation (Fig. 6).These parameters rise until an individualmaximum value is reached. This point is re-ferred to as maximum oxygen uptake (VíO

2

max) and forms an individual plateau valuethat cannot be exceeded. Consequently, VíO2max is a stable and reproducible individualphysiologic variable in humans. Age andbody position (lying, upright position) willchange the increase in cardiac output in rela-tion to exercise (slope and absolute values)due to the different cardiac pumping behavi-or.Cardiac output can be increased dependentof work rate by increasing both heart rateand stroke volume. Depending on the indivi-dual training condition, the stroke volume inwell-trained subjects is first increased fromapprox. 60 to 200 ml (30), followed by anincrease in heart rate. On the contrary, in un-trained subjects cardiac output is increasedvia an increase in heart rate. The poorer thesubject's training condition is, the faster heartrate increases. On the other hand, a person'sphysical training will increase stroke volu-me and reduce heart frequency (Fig. 6)


Exercise ProtocolsTTTTTreadmillreadmillreadmillreadmillreadmill

Bruce ProtocolBruce ProtocolBruce ProtocolBruce ProtocolBruce Protocol 4 steps /3 minutes(1.7 mph and 10% slope up to 4.2 mph and 16 % slope)

Balke ProtocolBalke ProtocolBalke ProtocolBalke ProtocolBalke Protocol Constant speed and increase of slope by 1%/min.

NaughtonNaughtonNaughtonNaughtonNaughton 15 test steps of 3 minutes each, starting at 3.2, km/h with 3.5% slope/3 min.respectively and increase in speed by 1.6 km/h every 6 min.

Bicycle ergometerBicycle ergometerBicycle ergometerBicycle ergometerBicycle ergometer

Incremental exercise testIncremental exercise testIncremental exercise testIncremental exercise testIncremental exercise test 60 RPM; increase 5 - 25 W/min.; planned test duration 6-12 minTest termination: exhaustion or termination criteria

RampRampRampRampRamp Continuously increasing exercise; increase at a one-second interval

An acute increase of haematocrit with heavywork load is possible in healthy subjects;however, this is not an important factor re-garding improvement of oxygen transporta-tion while exercising (30). In top athletes,however, training gives rise to an increase inblood volume and consequently in oxygentransport capacity and thus becomes relevantfor an increase in exercise capacity.Oxygen pulse (VíO2/HR) is a variable thatcan be determined by cardiopulmonary exer-cise testing and can be deduced from the pro-duct of stroke volume and the difference ofarterial and central-venous oxygen contentsi.e. VíO2/HR = SV x (CaO2 - CvO2).

Assuming that one of the variables (e.g. SV)remains constant during exercise, oxygenpulse is a function of the other respectively.During exercise, arterial-venous O2 diffe-rence remains constant as long as oxygenutilization and consequently arterial-venousO2 difference increases at the end of exer-cise. From now on oxygen pulse can be re-garded to be an indicator for the increase instroke volume.

Practical Guideline

Fig. 5

Stress testing methodsStandardized strStandardized strStandardized strStandardized strStandardized stress tests can be performedess tests can be performedess tests can be performedess tests can be performedess tests can be performedwith the help of:with the help of:with the help of:with the help of:with the help of:- bicycle ergometers- treadmill ergometers- hand-cranked ergometersEach of these methods has certain benefits.The decision as to which method is used de-pends on the space available and on theamount of patients to be tested. The test re-sults and predicted values are to be stateddependent on the applied testing method. Itshould however, be noted that with treadmilltests V'O2 max is about 7% - 10% higher thanwith bicycle tests. Whereby ventilatory andlactate parameters will be higher with bicyc-le tests than with treadmill tests (34, 35, 36).The test results are, furthermore, consider-ably influenced by the selected load proto-col. Basically, we can differentiate betweenconstant and constantly-increasing work loadtypes.DifDifDifDifDifferferferferferent modalities of constant exerent modalities of constant exerent modalities of constant exerent modalities of constant exerent modalities of constant exercisecisecisecisecisetests have been developed:tests have been developed:tests have been developed:tests have been developed:tests have been developed:- Maximum work load for a constant time.- Constant work load with a duration of

6 min.- Intermittent constant work load with a du-

ration of 6 min. with an increase in workload between two tests, whereby the pausebetween the tests is between 15 min. and24 hours.

Constantly increasing work loads can be real-ized in one test aiming at stressing the patientto a maximum.


Practical Guideline

Fig. 6

Fig. 7

Normal Athlete

Today, mainly steps of 2 (-1) minutes are pos-sible for technological reasons, however,with simultaneous right-ventricular cathete-rization different steps are required. The totalduration of work load should be approx. 10minutes and should not exceed 15 minutes.A duration of < 7 minutes can lead to errone-ous results (39). Depending on the subject'sor patient's condition, the examination should

Today, constantly increasing exercise tests(maximum or submaximum stress) are main-ly performed for practical reasons. The pre-viously described constant exercise tests havemainly been developed on the basis of sci-entific approaches, such as the determinati-on of VíO2 max or ventilatory kinetics. Itshould, however, be pointed out that V'O2max can only be precisely determined on thebasis of an intermittent constant exercise test.With constantly increasing exercise, on theother hand, that means without steady stateconditions, it is possible to achieve a peakwork load allowing to measure "VíO2 peak".It is an individual peak value that is recor-ded with the latter method, but not a plateauvalue as demanded for VíO2 max (37).It should be noted that the applied predictedvalues have to be obtained with the same test-ing method as applied during recording.In Western Europe bicycle ergometry is main-ly used. Work load steps of three or moreminutes steady state, that have been used afew years ago, are not required. Steady statecannot be achieved with maximum work load(38).

be planned in a way that the subject/patientis stressed to a maximum, provided that nosubmaximal exercise (50 - 85% of pred) isto be achieved for clinical reasons.

GoalsThe predicted exercise capacity can be esti-mated as follows (38):

WWWWWatts pratts pratts pratts pratts pred =ed =ed =ed =ed = Body weight Body weight Body weight Body weight Body weight (kg)(kg)(kg)(kg)(kg) x 3 x 3 x 3 x 3 x 3(Male)(Male)(Male)(Male)(Male)

Body weightBody weightBody weightBody weightBody weight(kg)(kg)(kg)(kg)(kg) x 2,5 x 2,5 x 2,5 x 2,5 x 2,5(Female),(Female),(Female),(Female),(Female),

minus 10% per age decade > 30 years, re-spectively (38).During bicycle ergometry 60 (70) RPMshould be used.The slope of the exercise increase dependson the planned exercise duration. However,the absolute increase/min. between 20 and50 watts will not influence the results duringramp testing with healthy subjects (40,41).In conclusion, we can say that symptom-li-mited exercise tests should meet the follow-ing demands: planned test period of 10 mi-nutes, predicted work load according to cal-culation given above, slope increase of workload/minute according to these two parame-ters. The initial work load should depend onthe estimated individual fitness.Measurements should be taken at rest for aperiod of at least 5 minutes before and afterthe exercise (36).


Literature:1.1.1.1.1. GoldhammerGoldhammerGoldhammerGoldhammerGoldhammer, S., Scherf, D.:, S., Scherf, D.:, S., Scherf, D.:, S., Scherf, D.:, S., Scherf, D.: Elektrokardiographische Untersuchungen bei Kranken mit Angina pectoris. Z.klin. Med. 122 (1932), 134 f.2.2.2.2.2. Dietrich, S., Schwiegk, H.:Dietrich, S., Schwiegk, H.:Dietrich, S., Schwiegk, H.:Dietrich, S., Schwiegk, H.:Dietrich, S., Schwiegk, H.: Angina pectoris und Anoxie des Herzmuskels, Z. klin. Med. 125(1933),

195 f.3.3.3.3.3. Hill, Hill, Hill, Hill, Hill, A.VA.VA.VA.VA.V., Long, C.N.H., Lupton, H.., Long, C.N.H., Lupton, H.., Long, C.N.H., Lupton, H.., Long, C.N.H., Lupton, H.., Long, C.N.H., Lupton, H. : Muscular exercise, lactic acid and supply und utilisation of oxygen. 1. Proc. Roy. Soc. London, Ser. B. 96 ( 1924), 438 - 475.4.4.4.4.4. ScholanderScholanderScholanderScholanderScholander, K.F, K.F, K.F, K.F, K.F....., Analyser for accurate estimating of respiratory gases in one-half cubic centimeter samples. J. Biol. Chem. 167 ( 1947), 235 - 259).5.5.5.5.5. Huckabee,WHuckabee,WHuckabee,WHuckabee,WHuckabee,W.E..E..E..E..E., J. Clin. Invest., 37 (1958), 1577 - 1592, 1593 - 1602: The role of anaerobic metabolism in the performance of mild muscular work. I. relationship to

oxygen consumption and cardiac output, and the effect of congestive heart failure. II. the effect of asymptomatic heart disease.6.6.6.6.6. TTTTTaylorayloraylorayloraylor, H.L., Buskirk, E., Henschel, , H.L., Buskirk, E., Henschel, , H.L., Buskirk, E., Henschel, , H.L., Buskirk, E., Henschel, , H.L., Buskirk, E., Henschel, A. A. A. A. A. , J. appl. Physiol. 8 (1955), 73 ff: Maximal oxygen intake as an objective measure of cardio-respiratory performance.7.7.7.7.7. Issekutz, B., Rohdahl, K.Issekutz, B., Rohdahl, K.Issekutz, B., Rohdahl, K.Issekutz, B., Rohdahl, K.Issekutz, B., Rohdahl, K., J.appl. Physiol., 16 (1961), 606 - 610: Respiratory quotient during exercise.8.8.8.8.8. WWWWWasserman, K., asserman, K., asserman, K., asserman, K., asserman, K., Whipp, B.J., Koyal, S.N., BeaverWhipp, B.J., Koyal, S.N., BeaverWhipp, B.J., Koyal, S.N., BeaverWhipp, B.J., Koyal, S.N., BeaverWhipp, B.J., Koyal, S.N., Beaver, , , , , WWWWW.L..L..L..L..L., J. appl. Physiol, 35 (1973), 236 - 243 : Anaerobic threshold and respiratory gas exchange during exercise.99999 H.L. H.L. H.L. H.L. H.L. TTTTTaylorayloraylorayloraylor, E. Buskirk, , E. Buskirk, , E. Buskirk, , E. Buskirk, , E. Buskirk, A. HenschelA. HenschelA. HenschelA. HenschelA. Henschel J. Appl. Phys. 8, (1955), 73 - 80: Maximal oxygen intake as an objective measure of cardio-respiratory performance.10.10.10.10.10. MellerMellerMellerMellerMellerowicz,Howicz,Howicz,Howicz,Howicz,H.Urban u. Schwarzenberg, M¸nchen, 1979: Ergometrie.111111.1.1.1.1. Gibbons, R. et al.Gibbons, R. et al.Gibbons, R. et al.Gibbons, R. et al.Gibbons, R. et al., JACC 30 ( 1997), 260 - 315: ACC/AHA Guidelines for exercise testing. A report of the american college of cardiology/american heart association

task force on practice guidelines (committee on exercise testing).12.12.12.12.12. WWWWWasserman, K., Hansen, JE., Sue, DYasserman, K., Hansen, JE., Sue, DYasserman, K., Hansen, JE., Sue, DYasserman, K., Hansen, JE., Sue, DYasserman, K., Hansen, JE., Sue, DY., ., ., ., ., Whipp, BJ.Whipp, BJ.Whipp, BJ.Whipp, BJ.Whipp, BJ.: Principles of exercise testing and interpretation. Philadelphia: Lea and Febiger, 1987.13.13.13.13.13. EschenbacherEschenbacherEschenbacherEschenbacherEschenbacher, , , , , WWWWW., Mannina, ., Mannina, ., Mannina, ., Mannina, ., Mannina, A.A.A.A.A., Chest 97 (1990), 263 - 267: An algorithm for the interpretation of cardiopulmonary exercise tests.14.14.14.14.14. Mc Connel, Mc Connel, Mc Connel, Mc Connel, Mc Connel, TR., Laubach CA., Clark BA.,TR., Laubach CA., Clark BA.,TR., Laubach CA., Clark BA.,TR., Laubach CA., Clark BA.,TR., Laubach CA., Clark BA., J Cardiopulmon Rehabil, 15 (1995), 257 - 261: Value of gas exchange analysis in heart disease.15.15.15.15.15. MitlehnerMitlehnerMitlehnerMitlehnerMitlehner,W,W,W,W,W., Kerb,W., Kerb,W., Kerb,W., Kerb,W., Kerb,W. Respiration, 61 (1994), 255 - 266: Exercise hypoxemia and the effects of increased inspiratory oxygen concentration in severe chronic obstruc-

tive pulmonary disease.16.16.16.16.16. Harris-Eze, Harris-Eze, Harris-Eze, Harris-Eze, Harris-Eze, AO., et alAO., et alAO., et alAO., et alAO., et al. Am. J Respir. Crit Care Med. 150 (1994), 1616 - 1622: Oxygen improves maximal exercise performance in interstitial lung disease.17.17.17.17.17. Howard, DK., IademarHoward, DK., IademarHoward, DK., IademarHoward, DK., IademarHoward, DK., Iademarco EJ., co EJ., co EJ., co EJ., co EJ., TTTTTrulock E.Prulock E.Prulock E.Prulock E.Prulock E.P,,,,, Clinics in chest medicine 15 (1994), 405 - 420: The role of cardiopulmonary exercise testing in lung and heart - lung

transplantation.18.18.18.18.18. Larsen,R., Svendsen, UG., Milman, N., BrLarsen,R., Svendsen, UG., Milman, N., BrLarsen,R., Svendsen, UG., Milman, N., BrLarsen,R., Svendsen, UG., Milman, N., BrLarsen,R., Svendsen, UG., Milman, N., Brenoe, J., Petersen, B.N.enoe, J., Petersen, B.N.enoe, J., Petersen, B.N.enoe, J., Petersen, B.N.enoe, J., Petersen, B.N.; Eur. Resp. J.,10 (1997), 1559-1565: Exercise testing in the preoperative evaluation of patients with

bronchogenic carcinoma.19.19.19.19.19. BolligerBolligerBolligerBolligerBolliger, CT, CT, CT, CT, CT et al et al et al et al et al., Am J Respir Crit Care Med 151 (1995), 1472 - 1480: Exercise capacity as a predictor of postoperative complications in lung resection candidates.20.20.20.20.20. MahlerMahlerMahlerMahlerMahler, DA., Hor, DA., Hor, DA., Hor, DA., Hor, DA., Horowitz, MB.owitz, MB.owitz, MB.owitz, MB.owitz, MB., Clinics in chest medicine 15 (1994), 259 - 270: Clinical evaluation of exertional dyspnea.21.21.21.21.21. MarMarMarMarMarx, H.H., Klepzig, H.x, H.H., Klepzig, H.x, H.H., Klepzig, H.x, H.H., Klepzig, H.x, H.H., Klepzig, H.: Medizinische Begutachtung innerer Krankheiten. Thieme Verlag, Stuttgart, 7∞, 1997.22.22.22.22.22. American thorax society:American thorax society:American thorax society:American thorax society:American thorax society: Evaluation of impairment/disability secondary to respiratory disorders. Am Rev Respir. Dis, 133 (1986), 1205 ff.23.23.23.23.23. Jones, N.L.Jones, N.L.Jones, N.L.Jones, N.L.Jones, N.L.: Clinical exercise testing. W.B. Saunders, 3∞, 1988.24.24.24.24.24. Whipp, B.J.,Whipp, B.J.,Whipp, B.J.,Whipp, B.J.,Whipp, B.J., Clinics in chest medicine, 15 (1994), 173 - 192: The bioenergetic and gas exchange basis of exercise testing..25.25.25.25.25. Johnson, B D., Beck, K CJohnson, B D., Beck, K CJohnson, B D., Beck, K CJohnson, B D., Beck, K CJohnson, B D., Beck, K C., Allergic and respiratory disease in sports medicine, 11 (1997), 1 - 34: Respiratory system responses to dynamic exercise.26.26.26.26.26. DempseyDempseyDempseyDempseyDempsey, JA, Hanson PG, Henderson,, JA, Hanson PG, Henderson,, JA, Hanson PG, Henderson,, JA, Hanson PG, Henderson,, JA, Hanson PG, Henderson, , KS, Schweiz. Z. Sportmedizin (1992), 40, 55 - 64: Demand vs. capacity in healthy pulmonary system.27.27.27.27.27. WWWWWarrarrarrarrarren JG, Jennings SJ, Clark en JG, Jennings SJ, Clark en JG, Jennings SJ, Clark en JG, Jennings SJ, Clark en JG, Jennings SJ, Clark TJHTJHTJHTJHTJH, Clin. Sci. (1984), 66, 79 - 85: Effect of adrenergic and vagal blockade on the normal human airway response to exercise.28.28.28.28.28. Morrison KJ, Gao Morrison KJ, Gao Morrison KJ, Gao Morrison KJ, Gao Morrison KJ, Gao YYYYY, , , , , VVVVVanhoutte PManhoutte PManhoutte PManhoutte PManhoutte PM. Am J Phys.(1990), 258, L 254 - L 262: Epithelial modulation of airway smooth muscle.29.29.29.29.29. AarAarAarAarAaron EA, Johnson BD, Seow CK, Dempsey JAon EA, Johnson BD, Seow CK, Dempsey JAon EA, Johnson BD, Seow CK, Dempsey JAon EA, Johnson BD, Seow CK, Dempsey JAon EA, Johnson BD, Seow CK, Dempsey JA, J Appl Physiol. (1992), 72, 1810 - 1817: Oxygen cost of exercise hyperpnea: measurement.30.30.30.30.30. Murray J F: Murray J F: Murray J F: Murray J F: Murray J F: The normal lung.2∞, W.B. Saunders, 1986.31.31.31.31.31. Whipp, BJ, Whipp, BJ, Whipp, BJ, Whipp, BJ, Whipp, BJ, WWWWWagneragneragneragneragner PD, PD, PD, PD, PD, Agusti Agusti Agusti Agusti Agusti A:A:A:A:A: in European respiratory monograph (1997), 2,6, 3-31: Response to exercise in healthy subjects.32.32.32.32.32. SautySautySautySautySauty, , , , , A, UldrA, UldrA, UldrA, UldrA, Uldryyyyy, C, Debetaz L-F, C, Debetaz L-F, C, Debetaz L-F, C, Debetaz L-F, C, Debetaz L-F, Leuenberger, Leuenberger, Leuenberger, Leuenberger, Leuenberger, P, P, P, P, P, Fitting, J-W, Fitting, J-W, Fitting, J-W, Fitting, J-W, Fitting, J-W,,,,, Eur. Respir. J. (1996), 9, 186 - 189: Differences in PO2 and PCO2 between arterial and arterialized

earlobe samples.33.33.33.33.33. Scuderi, Ph E, MacgrScuderi, Ph E, MacgrScuderi, Ph E, MacgrScuderi, Ph E, MacgrScuderi, Ph E, Macgregoregoregoregoregor, DA, Bowton, DL, Harris, LC, , DA, Bowton, DL, Harris, LC, , DA, Bowton, DL, Harris, LC, , DA, Bowton, DL, Harris, LC, , DA, Bowton, DL, Harris, LC, Anderson, R, James, RLAnderson, R, James, RLAnderson, R, James, RLAnderson, R, James, RLAnderson, R, James, RL, Am Rev. Resp. Dis. (1993), 147, 1354 - 1359: Performance characteristics and

interanalyser variability of PO2 measurements using tonometered human blood.34.34.34.34.34. Shepard, RJ,Shepard, RJ,Shepard, RJ,Shepard, RJ,Shepard, RJ, Int Z. angew. Physiol. (1966), 23, 219 - 230: The relative merits of the step test, bicycle ergometer and treadmill in the assesment of cardio-respiratory

fitness.35.35.35.35.35. Shepard, RJShepard, RJShepard, RJShepard, RJShepard, RJ, Standard tests of aerobic power. In Shepard RJ, : Frontiers of fitness, Charles E. Thomas, Springfield, 1971.36.36.36.36.36. Hansen, JE,Hansen, JE,Hansen, JE,Hansen, JE,Hansen, JE, Am Rev Resp. Dis. (1984), 129 Suppl. S 25 - S27: Exercise instruments, schemes and protocols for evaluating the dyspneic patient.37.37.37.37.37. TTTTTaylorayloraylorayloraylor, HL, Buskirk E., Henschel , HL, Buskirk E., Henschel , HL, Buskirk E., Henschel , HL, Buskirk E., Henschel , HL, Buskirk E., Henschel A,A,A,A,A, J appl. Physiol. (1955), 8, 73 - 80: Maximal oxygen uptake as an objective measure of cardio-respiratory performance.38.38.38.38.38. H. Lˆllgen.H. Lˆllgen.H. Lˆllgen.H. Lˆllgen.H. Lˆllgen. Kardiopulmonale Funktionsdiagnostik, Editio CIBA , Ciba - Geigy, Wehr, 2∞, 1992.39.39.39.39.39. Buchf¸hrBuchf¸hrBuchf¸hrBuchf¸hrBuchf¸hrererererer MJ, Hansen JE, Robinson MJ, Hansen JE, Robinson MJ, Hansen JE, Robinson MJ, Hansen JE, Robinson MJ, Hansen JE, Robinson TE, Sue DYTE, Sue DYTE, Sue DYTE, Sue DYTE, Sue DY, , , , , WWWWWasserman K, asserman K, asserman K, asserman K, asserman K, Whipp BJWhipp BJWhipp BJWhipp BJWhipp BJ: Am Rev Respir Dis (1982), 125, Suppl., 259: Optimizing the work rate protocol for

clinical exercise tests.40.40.40.40.40. Whipp BJ, Davies JA, Whipp BJ, Davies JA, Whipp BJ, Davies JA, Whipp BJ, Davies JA, Whipp BJ, Davies JA, TTTTTorrorrorrorrorres Fes Fes Fes Fes F, , , , , WWWWWasserman asserman asserman asserman asserman , J Appl Physiol (1981), 50, 217 - 221: A test to determine parameters of aerobic function during exercise.41.41.41.41.41. Davies JA, Davies JA, Davies JA, Davies JA, Davies JA, Whipp BJ, Lamarra N, Huntsman DJ, Frank MH, Whipp BJ, Lamarra N, Huntsman DJ, Frank MH, Whipp BJ, Lamarra N, Huntsman DJ, Frank MH, Whipp BJ, Lamarra N, Huntsman DJ, Frank MH, Whipp BJ, Lamarra N, Huntsman DJ, Frank MH, WWWWWasserman K,asserman K,asserman K,asserman K,asserman K, Med Sci Sports (1982), 14, 339 - 343: Effect of ramp slope on measurement of aerobic

parameters from the ramp exercise test.42.42.42.42.42. H. Roskamm, H. ReindellH. Roskamm, H. ReindellH. Roskamm, H. ReindellH. Roskamm, H. ReindellH. Roskamm, H. Reindell: Herzkrankheiten, Springer Verlag, Berlin. 1982.

Practical Guideline

Wolfgang Mitlehner, M.D.InternistPulmonary and Bronchial Diseases, AllergologySpecializing in Pulmonology and OncologyTurmstr. 21, Haus KD-10559 Berlin

+49 (0)30 3918747 +49 (0)30 39903889

eMail: [email protected]


Vmax and CardiosoftVmax and CardiosoftVmax and CardiosoftVmax and CardiosoftVmax and CardiosoftCPET by SensorMedics,ECG by Marquette Hellige.

Thanks to the close cooperation with Mar-quette-Hellige, SensorMedics successfullycombined Vmax and Cardiosoft in one sys-tem. Five different screen displays, that canbe selected during the test allow you to decidewhether you want to view CPET or ECG dataonly or whether you want to combine all dataon one screen.Of course, patient data doesn't have to be en-tered twice; a special program does that foryou automatically. It is also possible to re-cord an individual stress ECG or, optionally,an individual ECG at rest.

Are you looking for a sophisticated, high-endcardiopulmonary exercise testing system anddon't want to go without a high-quality ECGsystem? SensorMedics provides a perfectsolution and combines two leading productsin one system.

SensorMedics Vmax product seriesVmax is a versatile cardiopulmonary exer-cise testing system which meets the demandsof doctors whether they be in hospital or pri-vate practice. Whether you need a system forroutine testing or research, for adults or child-ren, for patients or athletes - Vmax can al-ways be tailored to your needs. Vmax is anopen system that allows you to record im-portant parameters such as O2 uptake, CO2output, RER, ventilation (V'E), O2 pulse etc.on a breath by breath basis. The results canbe displayed on-line in numeric and graphicform. The test can be performed via mouth-piece or mask.

Above:CPET including VmaxRight:Vmax CPET including Hellige ECG

All data at a glance:Stress ECG with CPET results

The lightweight mass flow sensor is insen-sitve to moisture and always provides high-ly-precise ventilatory data due to its smalldead space.With Vmax, you define the product. Youmight even design your own configuration,for example with indirect calorimetry, diffu-sion measurements (even during exercise),cardiac output, P0.1, bodyplethysmographyetc.Vmax, of course, provides a program for pul-monary function analysis. You can easilymeasure the flow-volume loop at rest andduring exercise and display both loops in onescreen for diagnosis of a ventilatory impair-ment.

Diagnostics


Indirect Calorimetry

AboveF/V loop during exerciseLeft:Spirometry measurement

Marquette-Hellige*1-ECGThe Hellige ECG is a first-class 12-channelPC-ECG and consists of Corina amplifier andCardiosoft software. Thanks to clinical veri-fication, the algorithms for ECG analysis ofMarquette-Hellige are the most precise andreliable algorithms in the world. You caneither use adhesive electrodes or the KISSsuction electrodes. During stress ECG recor-ding, a real-time arrythmia analysis and a 12-channel on-line ST analysis is performed.The Hellige Cardiosoft program automatical-ly controls the ergometer, as well as the bloodpressure measurement so that you can con-centrate on your patient.Optionally, the 12-channel ECG can be con-tinuously saved. ECG at rest including di-mensioning and interpretation is also avail-able as an option.

Vmax CPET andHellige ECG

Spirometry/Flow-Volume Cardiopulmonary Exercise Testing

The advantages at a glance:The advantages at a glance:The advantages at a glance:The advantages at a glance:The advantages at a glance:

Powerful analyzersFlow-volume loop during exerciseReport MakerPredicted Value MakerTutorArrhythmia detectionCPET stand-alone

Items included:Items included:Items included:Items included:Items included:

Computer, color ink-jet printer andmonitor on an ergonomic trolleyVmax analyzer and test moduleVmax software "Vision"Comprehensive help program Vmax"Tutor"Amplifier "Corina" made byMarquette-HelligeSoftware "Cardiosoft" made byMarquette-HelligeKISS suction electrodes or leads foradhesive electrodesIntegrated isolating transformerCalibration pumpAccessories kit

*1 a GE Medical Systems company

Diagnostics

Last but not least, Vmax makes it possible toperform a bronchial challenge testing withthe flow-volume loop.SensorMedics has always attached great im-portance to absolute precision. The analyzerscan be checked during automatic 2-point ca-libration. The same applies to volume calib-ration. A further unique feature is the built-in quality control for correct measurementperformance. If required, the system indica-tes accuracy and reproducibility of the flow-volume loop.The fast and precise analyzers meet the high-est standards and, unlike other types of ana-lyzers, don't have to be exchanged at regularintervals.The help program is a real trendsetter thatexplains and illustrates every measurementand setting with the assistance of animatedpictures. The tutor on CD-ROM, which isincluded, provides valuable informationregarding measurement technology and pa-rameters.


Vmax

Maintenance-free O2/CO

2 analyzer

Ambient module for temperature and pressureMass flow sensorBreath by breathMixing chamberPowerful PCColor ink-jet printerMobile cartVolume calibration programAutomatic gas calibrationPatient data baseSpirometry/flow volume programCPET programEntry of blood gas analysis values including markersCapnogram displayOff-line entry of blood pressure, SaO

2

User-specific graphics designUser-specific parameter tablesFlow-volume loop during exerciseAutomatic AT calculationManual AT calculationAutomatic VO

2 peak calculation

Manual VO2 peak calculation

Warning if limit value is exceededScreen and printer reportsUser-specific design of assessmentsPredicted value editorWork load controlMeasurement with elevated/lowered FIO

2

Indirect calorimetry- with hood- for ventilated patients- hood with elevated FiO

2

- hood for childrenCardiac outputSingle breath diffusion measurementIntrabreath diffusion measurementDiffusion during exerciseMembrane measurementFRC measurement N

2 washout

O2 single breath for closing volume

BodyplethysmographyP0.1/PmaxComplianceProvocationPulse oximeterCalibration and test gasPressure reducerNetworkLung function interpretation program3-channel ECG

StandardStandardStandardStandardStandard OptionOptionOptionOptionOption

All features at a glance:

Cardiopulmonary exercise testingand ECG

perfectly combinedin one unit.

Diagnostics

Hellige-ECG Cardiosoft

Amplifier module "Corina"

Software "Cardiosoft"Adhesive electrodes or KISS suction unit

Interface to SensorMedics Vmax

Data base

12-channel ergometry program

On-line arrhythmia detection

Warning in case of critical arrhythmias

On-line-ST analysisTrend graphsSingle electrode controlHR alarm, acoustically and opticallyAnti-drift system35 Hz and 50 Hz filterAutomatic zeroingDisplay as on recording paperExercise controlOn-line storage of entire ECGECG at restInterpretation of ECG at restArrhythmia marking and classification

StandardStandardStandardStandardStandard OptionOptionOptionOptionOption


Oxycon MobileOxycon MobileOxycon MobileOxycon MobileOxycon MobileA milestone in CPET

Execellent diagnostic possibilities are achievedby traditional stress testing equipment liketreadmill and bicycle ergometer.Up until now this equipment has been limited toindoor usage.Now we have the Oxycon Mobile.

Fig. left:Display of anaerobicthresholdBelt system

Main features:

Telemetric data transferPortable, lightweight unit attached toa belt system, which is slipped overthe shoulders.Complete CPET test including flow-volume loop, heart rate, ECG,anaerobic threshold etc.Long-range telemetry for real-timedata monitoringApplicable to a wide range of testsubjects from seriously ill patients toelite athletesPowerful evaluation software withreport generator

Diagnostics

Fields of application:Fields of application:Fields of application:Fields of application:Fields of application:

Pulmonology, cardiology, intensive care

Suspected stress-induced asthmaMonitoring of patients with heartdiseasesMonitoring of parenteral fed patients

RehabilitationTherapy monitoring

Occupational medicineDetermination of occupationalexercise toleranceDetermination of degree of handicap

Sports medicineOptimizing of training

Oxycon Mobile offers on-the-spot measure-ments of all relevant CPET parameters. Thesmall sophisticated unit is attached to acomfortable belt system. This is slipped overthe test subject's shoulder. The test can beperformed via a breathing mask and thesubject is not impeded by tubes and cables.The recorded data is telemetrically transferredto the PC or saved on a small chip card. Afterbeing transferred, the data is analyzed usingthe powerful Oxycon Software by Jaeger.

Oxycon Mobile records all key parameterssuch as:

Ventilation V'EVO2, VCO2

Anaerobic thresholdRERHREQO2, EQCO2


In regards to exercise tolerance, cardiopulmonary exercise testing is an excellent tool for diagnosis andtherapy. However, the values obtained at rest during cardiopulmonary function diagnostics are often notenough to establish a proper therapy. The results of cardiopulmonary exercise testing can be interpreted onthe basis of the nine-panel graph which gives a clearly structured overview of exercise capacity, cardiacparameters, pulmonary performance values and gas exchange parameters.

Clinical Importance of CPETClinical Importance of CPETClinical Importance of CPETClinical Importance of CPETClinical Importance of CPETAuthor: Prof. Karl-Heinz R¸hle, M.D.

Indications forIndications forIndications forIndications forIndications for cardiopulmonar cardiopulmonar cardiopulmonar cardiopulmonar cardiopulmonary exery exery exery exery exercise testingcise testingcise testingcise testingcise testing

A. Disability assessmentA. Disability assessmentA. Disability assessmentA. Disability assessmentA. Disability assessmentMaximum exercise capacityFactors of exercise limitation

B. Risk/prB. Risk/prB. Risk/prB. Risk/prB. Risk/prognosisognosisognosisognosisognosisRisk assessment prior to pulmonary resection (pneumonectomy, lobectomy)Risk assessment prior to heart transplantation

C. C. C. C. C. Therapy assessmentTherapy assessmentTherapy assessmentTherapy assessmentTherapy assessmentTrainingO2 therapyDrug therapy

Essay

ty can be better assessed by determiningmaximum oxygen uptake with regard to thepossible performance.

Factors of exercise limitationEven with a great deal of expenditure cardi-opulmonary exercise testing only allows todescribe approximately 50% of the influenc-ing factors. Other limiting factors, such asdyspnea or claudicating pain cannot be quan-tified objectively. A study with COPD pa-tients showed that in 46% of all cases musc-le exhaustion was the main cause for exer-cise cessation. Cessation due to dyspnea wasonly reported in 36 % of the cases. Patientswith interstitial pulmonary fibrosis howeverceased exercising due to dyspnea (62%) andmuscle exhaustion (25%).To determine maximum oxygen uptake, theBorg scale is highly recommended. Dyspneaoften rises linearly with increasing work load(V'O2,Watt or V'E/MVV); however, the workload dependant increase of dyspnea varieswith the type of disease and can also be usedto estimate the probable maximum exercisecapacity during examination.An important aspect of cardiopulmonaryexercise testing is that it allows to exclude arelevant cardiopulmonary impairment.

A. Disability assessmentA. Disability assessmentA. Disability assessmentA. Disability assessmentA. Disability assessmentMaximum exercise capacityWith good patient effort, definition of maxi-mum oxygen uptake is the best method todefine a subject's physical exercise capacity.Indication that the subject has reached his/her maximum exercise capacity is the pla-teau-formation of the continuously measuredV'O2 in the ramp protocol, despite increasingwork load. This value is referred to as V'O2max. If V'O2 rises only slightly, one can besure that the patient is stressed to a maxi-mum and consequently a cardiopulmonarylimitation is present. This is of special im-portance for disability assessments. If no pla-teau is reached, we talk about Peak V'O2 (orV'O2 peak). In fact, this is the highest V'O2achieved during the test. Here, it is not pos-sible to decide whether patient effort wasgood or not.In this context, it is helpful to consider baseexcess (BE). If this value falls below -6 upto -9 mmol/l in healthy subjects, it can beassumed that the subject has been stressed toa maximum.

Especially in the presence of pulmonary di-seases maximum exercise capacity cannot beexactly predicted on the basis of functionalparameters measured at rest.It is therefore indispensable for disabilityassessments to describe the impairmentcaused by e.g. functional pulmonary or car-diac disorders during exercise, as well as theresulting reduced exercise capacity on thebasis of V'O2 max. Functional impairmentsare highly relevant with regard to their ef-fects on occupation and way of life.

DisabilityIn some occupations, people are exposed toshort-termed maximum loads. By determin-ing V'O2 peak, it can be decided whether thesubject can meet this requirement during spe-cific conditions (disability for a certain oc-cupation).The measurement of V'O2 peak provides im-portant information about the endurance ca-pacity. The demands of a normal 8-hourworking day should be considerably belowthe endurance limit.If an exact description of the working placeincluding the average oxygen uptake duringwork or power in watts is available, disabili-


If V'O2max is less than 60% of the predictedvalue, the removal of more than one lung lobeis not recommended.If V'O2max is higher than 75% of the predic-ted value it can be assumed that no post-sur-gical complications will occur.

Risk assessment for heart transplantpatientsPrognosis and clinical trend in the case ofcardiac insufficiency can be examined on thebasis of the patient's own account, accordingto NYHA classification or by objective test-ing procedures with the help of Wmax orV'O2 peak. There is a good correlationbetween the measured V'O2 peak and themortality in patients with heart failure accor-ding to NYHA III and IV.With a cutoff of V'O2max below 10 ml/kg/min. mortality after one year is 77%.

C. C. C. C. C. Therapy assessmentTherapy assessmentTherapy assessmentTherapy assessmentTherapy assessmentTrainingOne of the most important tasks of rehabili-tation is the increase of exercise capacity bytraining the muscles of the upper and lowerextremities.In the case of COPD, maximum exercise ca-pacity is limited during exercise as the largeand small airways will collapse. As the end-expiratory volume increases with increasingwork load, the lungs are working in an unfa-vorable area of the pressure-volume-curve.Furthermore, there is fatigue of the periphe-ral muscles, increasing hypoxemia in the pre-sence of severe obstruction, a reduction incardiovascular capacity as well as the incre-ased lactic acidosis in the presence of a re-duced capacity of the peripheral muscles.In the case of COPD, cardiopulmonary exer-cise testing is important to control muscletraining, i.e. when defining work load levelsfor training purposes.At the beginning of an exercise program theexercise intensity, at which an increase inexercise capacity under training is to be ex-pected, has to be defined. However, thereare still no standardized guidelines regardingduration, frequency and intensity of training.

Prof. Karl-Heinz R¸hle, M.D.Klinik AmbrockAmbrocker Weg 60D-58091 Hagen

+49 (0)2331 974 0eMail: [email protected]

Essay

This is valid, whenever a patient complainsabout stress dyspnea, but nevertheless rea-ches his/her steady state/unsteady state exer-cise capacity according to the respective re-ference values. Consequently, exercise capa-city is normal but the subjects are either notable to assess their condition or suffer frompsychogenically induced dyspnea. With nor-mal exercise capacity the patient can be re-assured. Alternatively a psychotherapy or adrug therapy (sedatives, anxiolytics) can beprescribed. Additional examinations areoften not required. Lack of training andreduced exercise capacity, for example incase of adipositas, cannot be differentiatedfrom cardiac impairments.It should be generally noted that the resultsof the cardiopulmonary exercise test cannotbe assigned to a specific clinical picture, butonly provides important information for fur-ther diagnosis. Poorly trained subjects or pa-tients with cardiac diseases have a similiarreduced maximal oxygen uptake, breathingreserve (MVV/V'E), oxygen pulse and lowanaerobic threshold. Reduced load capacity,including the early onset of lactic acidosis,indicate a poor training condition. This in-formation cannot be obtained by clinical data,body-plethysmography or blood gas analy-sis at rest.

B. Risk/prB. Risk/prB. Risk/prB. Risk/prB. Risk/prognosisognosisognosisognosisognosisRisk assessment prior to pulmonaryresection

By quantifying the functional reserves, in thecase of pulmonary resection it is possible todefine which patients are at risk and conse-quently the pre/post-surgical mortality ratedeclines. An important goal is the pre-surgi-cal determination of the risk forcomplications after a major surgery. Nowa-days the most important information is re-trieved out of the measured static and dyna-mic lung-volume before surgery, out of whichthe post-surgery values for FEV1 can be de-rived and estimated, even better in combina-tion with a quantitative perfusion-scintigra-phy. Due to the high discrimination, deter-mination of maximum V'O2 for estimationof the surgical risk is favored.

With the help of a ramp protocol, maximumexercise capacity, as well as a range for trai-ning can be defined on the basis of whichthe anaerobic threshold is determined. Somestudies recommend a range from 50% of peakoxygen uptake to values below maximumoxygen uptake.Cardiopulmonary exercise testing allows toobjectively quantify the success of trainingprograms. Parameters to be measured are,among others, maximum oxygen uptake, lac-tate, minute volume, breathing frequency,V'CO2, ventilatory equivalents, heartrate,VD/VT and anaerobic threshold. Theseparameters can be determined best on thebasis of a ramp protocol performed prior toand after training.

O2 therapyTo compensate hypoxemia and its effects onexercise capacity, it can be attempted to in-crease exercise capacity by O2 insufflationduring exercise. Studies regarding O2 thera-py in the presence of different pulmonary di-seases are available for patients with COPD,interstitial fibrotic lung diseases and cysticfibrosis.

Drug therapyEndurance capacity is a very sensitive andclinically relevant variable for evaluatingdrug effects, especially of fl-sympathicomi-metics and anticholinergics. By measuringlung volumes such as FEV1, FVC and inspi-ratory capacity (IC), an improvement afteradministration of anticholinergics can bedocumented. Hyperinflation at rest, measu-red via IC, is a very good predictive parame-ter of V'O2 max. Dynamic hyperinflation andthe simultaneous increase of the endexpira-tory volume (EELV) during exercise andtheir reduction after administration ofantiobstructive medication correlates bestwith the increase in endurance capacity.


Evaluation and InterpretationEvaluation and InterpretationEvaluation and InterpretationEvaluation and InterpretationEvaluation and Interpretationof a cardiopulmonary exercise test

Cardiopulmonary exercise testing is a comprehensive testing procedure suited for differential diagnosis andexamines a subject's cardiopulmonary exercise capacity or limitation. In addition to cardiac parameters,(e.g. stress ECG) respiratory parameters are recorded at defined work rates. The test provides a variety ofparameters which, as compared to the individual stress ECG, allow for a comprehensive assessment.

Comments on the evaluation and interpreta-tion of a cardiopulmonary exercise test withthe help of these graphs, explained step bystep, follow. As far as the sequence of theindividual graphs is concerned, there are dif-ferent views (e.g. Wasserman (1999), R¸hle(2001)) depending on where emphasis isplaced.As far as I'm concerned, the procedure de-scribed below is the best suited.

Assessment of cardiac (cardiopul-Assessment of cardiac (cardiopul-Assessment of cardiac (cardiopul-Assessment of cardiac (cardiopul-Assessment of cardiac (cardiopul-monarmonarmonarmonarmonary) exery) exery) exery) exery) exercise capacitycise capacitycise capacitycise capacitycise capacityWhat is the subject's exerWhat is the subject's exerWhat is the subject's exerWhat is the subject's exerWhat is the subject's exercise capacitycise capacitycise capacitycise capacitycise capacity(Graph 3)?(Graph 3)?(Graph 3)?(Graph 3)?(Graph 3)?On the basis of the predicted values in Graph3, it can be immediately recognized whetherthe subject has reached or even exceeded his/her expected exercise capacity and oxygenuptake (as in Fig. 1: 194% pred). If reached,these values clearly show that none or at leastno severe limitation or impairment is pres-ent. It should, however, be noted that oxy-gen uptake in obese subjects is higher thanin persons of normal weight. This is due tothe increased body mass and means that oxy-gen uptake, although reduced, can reach nor-mal values if the overweight is not conside-red in the predicted values (see Fig. 3 => se-lect correct predicted values!).

The goal of this essay is to explain an easyand understandable procedure that allowsassessment of individual areas of exercise li-mitation in order to deduce clear results.There are a variety of proposals and flowcharts in literature (e.g. Eschenbacher (1990),Roca (1997), Wasserman (1999), Schardt(1999)) describing certain methods, one ofwhich is the evaluation on the basis of thenine-panel graph. This method has been re-commended by Wasserman for years and hasbeen proven to be well suited. Although re-cording of the dynamic flow-volume loopduring exercise, which has become increa-singly important during the past years, hasnot yet been considered. As seen in Fig. 1,the nine-panel graph can be divided into se-veral areas (whereby the graphs are numbe-red from left to right):VVVVVentilation:entilation:entilation:entilation:entilation: Graph 1, 4 and 7Cardiopulmonary:Cardiopulmonary:Cardiopulmonary:Cardiopulmonary:Cardiopulmonary: Graph 2, 3 and 5Gas exchange:Gas exchange:Gas exchange:Gas exchange:Gas exchange: Graph 6, 9 and 4Metabolism:Metabolism:Metabolism:Metabolism:Metabolism: Graph 8AnaerAnaerAnaerAnaerAnaerobic throbic throbic throbic throbic threshold:eshold:eshold:eshold:eshold: Graph 5, 6, 8 and 9Recording of the flow-volume loop duringexercise and comparing it with the maximalflow-volume loop provides additional infor-mation, mainly on ventilatory limitations(Fig. 2).

Fig. 1 (left): CPET test on the basis of the nine-panel graph. The graphs arenumbered from left to right as follows: 1-3, 4-6 and 7-9.

Fig. 2. (top): Left curve: Maximal and dynamic F/V loop of a subject with nolimitation. Right curve: Obstruction. The graph shows that ventilatory limitationis reached (flows, tidal volume).

How does oxygen uptake incrHow does oxygen uptake incrHow does oxygen uptake incrHow does oxygen uptake incrHow does oxygen uptake increase duringease duringease duringease duringease duringexerexerexerexerexercise (Graph 3)?cise (Graph 3)?cise (Graph 3)?cise (Graph 3)?cise (Graph 3)?Linearity?In healthy subjects, oxygen uptake normallyincreases linearily with increasing work loadand, according to Wasserman, can beestimated as follows:V'OV'OV'OV'OV'O22222 [ml/min] = 151 mL/min + 5.8*body weight[kg] [ml/min] = 151 mL/min + 5.8*body weight[kg] [ml/min] = 151 mL/min + 5.8*body weight[kg] [ml/min] = 151 mL/min + 5.8*body weight[kg] [ml/min] = 151 mL/min + 5.8*body weight[kg]

+ 10.5 * work load[W+ 10.5 * work load[W+ 10.5 * work load[W+ 10.5 * work load[W+ 10.5 * work load[Watt]att]att]att]att]11111

This linear relation is also valid for obesesubjects (Fig. 3, left); however, oxygenuptake is parallel shifted upwards due to bodyweight.

Flatening with increasing work rate?Each subject has an individual cardiovascu-lar/cardiopulmonary limitation, which is re-flected by a flatening in oxygen uptake de-spite increasing work load. However in nor-mal subjects, this flatening is often not rea-ched (xV'O2 peak), as this requires a lot ofeffort and healthy subjects are rarely willingto do so, so that this flatening is only rea-ched with really limited patients or with topathletes who stress themselves to a maximum(Fig. 3 - right).

Essay

1 2 3

4 5 6

7 8 9

Author: Hermann Eschenbacher, Ph.D.


symptoms (e.g. pulmonary limitation), max-imum heart rate should almost reach themaximum predicted value (less than 10beats).

How does heart rate rise duringHow does heart rate rise duringHow does heart rate rise duringHow does heart rate rise duringHow does heart rate rise duringexerexerexerexerexercise (Graph 5)?cise (Graph 5)?cise (Graph 5)?cise (Graph 5)?cise (Graph 5)?Oxygen transport can be described on thebasis of Fick's Principle:VVVVVOOOOO22222 = HR * SV = HR * SV = HR * SV = HR * SV = HR * SV * (CaO * (CaO * (CaO * (CaO * (CaO22222 - CvO - CvO - CvO - CvO - CvO22222).).).).).

Increasing heart rate (HR), increasing strokevolume (SV), as well as the difference of oxy-gen content between arterial and mixed-ve-nous blood, (CaO2-CvO2) contribute to in-crease V'O2. In general, all three parameterschange with increasing work load wherebythere will be an approximately linear relati-on between heart rate and oxygen uptake inhealthy subjects. However, the lower the stro-ke volume (e.g. in unfit or obstructive sub-jects), the higher the basic heart rate has tobe. If no further increase in stroke volume ispossible, and if CaO2-CvO2 is already utili-zed, there is no choice but to increase heartrate in order to increase oxygen uptake. Thisis reflected by the overproportional increasein Fig. 4.

How does oxygen pulse rise withHow does oxygen pulse rise withHow does oxygen pulse rise withHow does oxygen pulse rise withHow does oxygen pulse rise withincrincrincrincrincreasing work load (Graph 2)?easing work load (Graph 2)?easing work load (Graph 2)?easing work load (Graph 2)?easing work load (Graph 2)?On the basis of Fick's Principle oxygen pul-se is obtained through division by heart rate:OOOOO22222 Pulse = Pulse = Pulse = Pulse = Pulse = V'OV'OV'OV'OV'O22222/HR = SV/HR = SV/HR = SV/HR = SV/HR = SV * (CaO * (CaO * (CaO * (CaO * (CaO22222 - CvO - CvO - CvO - CvO - CvO22222)))))

Consequently, oxygen pulse measures theamount of oxygen that is transported by theblood per beat and therefore directly reflectscardiac function; if cardiac function is good,the amount of oxygen transported per beat ishigh. O2 pulse is continuously increasing dur-ing exercise (increase in SV and in CaO2-CvO2). In unfit or, for example obstructivesubjects, O2 pulse will continuously increase;however, the curve trend will be lower dueto smaller stroke volume.If cardiac function is poor or bad, the strokevolume is already utilized at low work rate

Fig. 3. Oxygen uptake: Position, slope, linearity (modified accoding to Wasserman (1999)).See text for explanation.

levels so that oxygen transport per beat canonly be increased by oxygen extraction.Since this increase is soon limited, O2 pulsewill reach a plateau as soon as maximal ex-traction is reached. A further increase in workrate will then consequently result in an over-proportional increase in heart rate (see Fig.4).

Assessment of ventilatorAssessment of ventilatorAssessment of ventilatorAssessment of ventilatorAssessment of ventilatory perfory perfory perfory perfory perfor-----mancemancemancemancemanceGraph 1, 4, 7 as well as dyn. F/VGraph 1, 4, 7 as well as dyn. F/VGraph 1, 4, 7 as well as dyn. F/VGraph 1, 4, 7 as well as dyn. F/VGraph 1, 4, 7 as well as dyn. F/V-loop-loop-loop-loop-loopDoes ventilation rise during exerDoes ventilation rise during exerDoes ventilation rise during exerDoes ventilation rise during exerDoes ventilation rise during exercisecisecisecisecise(Graph 1)?(Graph 1)?(Graph 1)?(Graph 1)?(Graph 1)?Ventilation normally increases linearily un-til the anaerobic threshold is reached and ri-ses overproportionally due to the increasedamount of anaerobically produced CO2 du-ring exercise provided that the breathing re-serve is sufficient.

Is the ventilatorIs the ventilatorIs the ventilatorIs the ventilatorIs the ventilatory demand incry demand incry demand incry demand incry demand increasedeasedeasedeasedeased(Graph 4)?(Graph 4)?(Graph 4)?(Graph 4)?(Graph 4)?Respiratory drive is mainly controlled by theCO2 that has been released. A healthy sub-ject requires an increase in ventilation byabout 20 to 25 L per additional liter of CO2.If dead space ventilation is increased and/oran impairment in gas exchange is present,ventilation must be increased so that the sameamount of CO2 can be released. This graphis discussed in detail later in relation to therespiratory equivalents (Graph 6).

BrBrBrBrBreathing pattern, breathing pattern, breathing pattern, breathing pattern, breathing pattern, breathing reathing reathing reathing reathing reserveeserveeserveeserveeserve(Graph 7)?(Graph 7)?(Graph 7)?(Graph 7)?(Graph 7)?Depending on the breathing frequency (BF)and tidal volume (VT) there are several pos-sibilities to reach the same ventilation:For example: VE=50 L/min can be reachedas follows: 50 breaths ‡ 1 L (lower isopleth)or 20 breaths ‡ 2.5 L (upper isopleth, seeFig. 1, Graph 7). Subjects with flow limita-tions will try to breathe as deeply and as slow-ly as possible, whereby the V'E curve willbe plotted along the upper isopleth. A sub-ject with ventilatory restriction, on the otherhand, achieves maximum tidal volume quik-kly due to his/her low VC and then ventilati-on can only be increased by increasing brea-thing frequency. Consequently, VT will soonreach a plateau, move towards the lower iso-pleth and probably intersect.Furthermore, the measured maximum volun-tary ventilation (MVV) and inspiratory ca-pacity (IC) can be plotted illustrating whe-ther the subject has reached his/her maximumventilation and consequently whether a ven-tilatory limitation is present.

Essay

As long as the individual body cells are suf-ficiently supplied with oxygen, the increaseis linear. As soon as the supply is no longersufficient, the curve flattens. If limitationstarts already below the predicted value, wecan assume for sure that exercise capacity islimited. Limitation is the greater, when flaten-ing starts earlier. Nevertheless, the body hasto meet the increased demands, which meansthat energy has to be produced anaerobical-ly. Due to the limited anaerobic capacity, thesubject will soon stop exercising dependingon his/her individual reserves.

Slope of oxygen uptake?Another important aspect is the increase ofoxygen uptake during exercise. The slope ofV'O2 with increasing work load (= aerobiccapacity, normally approx. 10.5 ml/watt1, seeabove) provides information on whether theperipheral muscle cells are sufficiently sup-plied with oxygen. If not, for example in thepresence of peripheral stenosis or a left ven-tricular functional impairment, a lower slo-pe can be observed (Fig. 3, center). To beable to assess this increase, it is recommen-ded to simultaneously record work load inGraph 3 and to plot it in relation to V'O2 witha scale of 1:10 (an increase of 1 watt equalsan 10 mL V'O2 increase), so that both slopescan be directly compared with each other (seeFig. 1, Graph 3: green and blue curve).

Does heart rate rise continuously; what isDoes heart rate rise continuously; what isDoes heart rate rise continuously; what isDoes heart rate rise continuously; what isDoes heart rate rise continuously; what ismaximum HR (Graph 2)?maximum HR (Graph 2)?maximum HR (Graph 2)?maximum HR (Graph 2)?maximum HR (Graph 2)?In healthy subjects, heart rate is expected torise continuously and approximately linear-ly with work load. In healthy subjects andathletes a slight decline of the slope can of-ten be observed at high work rate levels, whe-reas mainly patients with cardiac impair-ments often show an increase of the slope.Especially when testing patients with pace-makers, investigators should pay close atten-tion to a continuous increase in heart rate.In order to assure that the subject is stressedto a maximum and is not limited by other


In close vicinity to the anaerobic threshold,a healthy subject has a ventilatory demandof approximately 20 to 25 L for one liter ofoxygen uptake or 25 to 30 L VE to releaseone liter of CO2.Both an increased dead space ventilation andan impaired gas exchange will result in anincreased ventilation to assure an adequategas exchange. Consequently, the respiratoryequivalents are increased (also see Fig. 7,Graph 6).

DifDifDifDifDiffusion impairment orfusion impairment orfusion impairment orfusion impairment orfusion impairment or incr incr incr incr increased deadeased deadeased deadeased deadeased deadspace (if rspace (if rspace (if rspace (if rspace (if requirequirequirequirequired, Graph 9)?ed, Graph 9)?ed, Graph 9)?ed, Graph 9)?ed, Graph 9)?There are different possibilities to differen-tiate between an increased dead space venti-lation and an impaired gas exchange:

Blood gases: PaO2, PaCO2

Dead space ventilationDead space ventilationDead space ventilationDead space ventilationDead space ventilationIf blood gases are taken during exercise, theamount of dead space ventilation can be cal-culated according to the Bohr formula:VD/VT = (PaCOVD/VT = (PaCOVD/VT = (PaCOVD/VT = (PaCOVD/VT = (PaCO22222 ñ PECO ñ PECO ñ PECO ñ PECO ñ PECO22222)/PaCO)/PaCO)/PaCO)/PaCO)/PaCO22222 ñVDapp/VT ñVDapp/VT ñVDapp/VT ñVDapp/VT ñVDapp/VT44444

At maximum work load, this value is nor-mally between 0.15 and 0.20, values higherthan 0.30 indicate an increased dead spaceventilation.AlveolarAlveolarAlveolarAlveolarAlveolar-ar-ar-ar-ar-arterial oxygen difterial oxygen difterial oxygen difterial oxygen difterial oxygen differferferferferenceenceenceenceenceP(A-a)OP(A-a)OP(A-a)OP(A-a)OP(A-a)O22222:::::A diffusion impairment can be best deter-mined on the basis of P(A-a)O2 which is cal-culated from blood gases and CPET data:P(A-a)OP(A-a)OP(A-a)OP(A-a)OP(A-a)O22222 = = = = = FiOFiOFiOFiOFiO22222 * (BP ñ 47) ñ PaCO * (BP ñ 47) ñ PaCO * (BP ñ 47) ñ PaCO * (BP ñ 47) ñ PaCO * (BP ñ 47) ñ PaCO22222 * (FiO * (FiO * (FiO * (FiO * (FiO22222

+ (1-FiO+ (1-FiO+ (1-FiO+ (1-FiO+ (1-FiO22222)/RER))/RER))/RER))/RER))/RER)

At rest, this value is normally between 10 to15 mmHg; during exercise, this value is age-dependent and is between 25 (subjects < 40years) and 35 mmHg (> 50 years). If theblood gas values are plotted in Graph 9 to-gether with the values for PETO2 and PET-CO2, this information is immediately display-ed on the screen.

Slope and offset of ventilation(Graph 4)?As already mentioned, ventilation is com-posed of V'E = V'A + V'D.Normally, there is an increase in ventilationof aproximately 25 liters per liter CO2. Anincreased dead space ventilation will there-fore mainly give rise to a parallel displace-ment, whereas a disturbed gas exchange dur-

Fig. 4. Increase in heart rate with oxygen uptake(Graph 5; for a better overview the 2. Y-axis hasbeen left out).

Left: Athlete (low HR, low slope); Center: un-trained subject (increased heart rate but linearand normal slope, finally slightly flattened);Right: cardiac limitation (clear unproportionalslope at the end of exercise).

Fig. 5: Oxygen pulse (modified acc. toWasserman (1999))

Essay

ing exercise will result in an increased slo-pe5.

Consequently, evaluation of this slope hasincreasingly gained importance over the lastfew years, mainly with regard to the degreeof severity of the impairment, as well as re-garding the mortality (Johnson (2000), Kle-ber (2000), Meyer (2001)).

Determination of the aerDetermination of the aerDetermination of the aerDetermination of the aerDetermination of the aerobic-ana-obic-ana-obic-ana-obic-ana-obic-ana-earearearearearobic transition (Aobic transition (Aobic transition (Aobic transition (Aobic transition (ATTTTT thr thr thr thr threshold)eshold)eshold)eshold)eshold)Graph 5, 6, 8 (and 9):Graph 5, 6, 8 (and 9):Graph 5, 6, 8 (and 9):Graph 5, 6, 8 (and 9):Graph 5, 6, 8 (and 9):

What is the subject's enduranceWhat is the subject's enduranceWhat is the subject's enduranceWhat is the subject's enduranceWhat is the subject's endurancecapability?capability?capability?capability?capability?In addition to other findings (is exercise ca-pacity normal, at least up to AT? Is AT withinthe normal range? Are impairments occuringbelow AT?) this transition is of importancemainly for diagnosing exercise capacity inthe field of endurance sports, as well as fordisability assessments. Due to the additionalanaerobically produced CO2, cardiopulmo-nary exercise testing allows reliable deter-mination of anaerobic threshold by non-in-vasive methods on the basis of several re-corded or computed parameters:

AT-determination on the basis of RER(Graph 8):If the CO2 release exeeds the O2 uptake (i.e.no hyperventilation, CO2-rebreathing etc., i.e.RER > 1) during incremental exercise tests,the additional CO2 has to be produced anae-robically. However, not every subject is ableto adjust his/her metabolism to combust100% carbohydrates. Consequently, additi-onal anaerobically produced energy has tobe provided at, for example, RER = 0.9 (of-ten reflected by the quick increase in RER,also see Fig. 6, bottom left).Therefore, AT determination via RER = 1 canonly be regarded as a rough estimation andRER = 1 as the upper limit for AT.

AT determination according to V-Slope(Graph 5, second Y-axis):At rest and at low work rate levels both car-bohydrates (RER = 1.0) and fat (RER = 0.7)are combusted (mixed combustion) so thatthe ratio between oxygen uptake and carbon-dioxide release is approximately 0.85.This energy production is reflected by thefirst linear portion (also see Fig. 6, top left).

BrBrBrBrBreathing pattern, breathing pattern, breathing pattern, breathing pattern, breathing pattern, breathing reathing reathing reathing reathing reserveeserveeserveeserveeserve(Dynamic F/V(Dynamic F/V(Dynamic F/V(Dynamic F/V(Dynamic F/V-loop)?-loop)?-loop)?-loop)?-loop)?Thanks to modern digital technology it is,however, easier to record the dynamic flow-volume loop during exercise in addition tothe maximum flow-volume curve at rest (seeFig. 2). This allows you to immediately de-termine whether a subject's ventilatory reser-ves are sufficient or whether his/her maxi-mum possible flow and tidal volume havealready been reached, i. e. whether he/she isalready exhausted. The evaluation of dyna-mic flow-volume loops are discussed in de-tail by Schwarz in Fritsch (1999) and in theJAEGER info, Special Edition Ergo-spirometry (1999).

Assessment of a ventilation-Assessment of a ventilation-Assessment of a ventilation-Assessment of a ventilation-Assessment of a ventilation-perfusion mismatchperfusion mismatchperfusion mismatchperfusion mismatchperfusion mismatchGraph 6, 4 (and 9)Graph 6, 4 (and 9)Graph 6, 4 (and 9)Graph 6, 4 (and 9)Graph 6, 4 (and 9)

Is the ventilatorIs the ventilatorIs the ventilatorIs the ventilatorIs the ventilatory demand incry demand incry demand incry demand incry demand increasedeasedeasedeasedeased(Graph 6 and 4)?(Graph 6 and 4)?(Graph 6 and 4)?(Graph 6 and 4)?(Graph 6 and 4)?In Graph 6, the two ventilatory equivalentsfor oxygen (EQO2 ª V'E/V'O2)

2 and carbondioxide (EQCO2 ª V'E/V'CO2)

3 are display-ed. Ventilation V'E is composed of alveolarventilation V'A (here gas exchange takesplace) and dead space ventilation V'D:V'E = V'A + V'D.During exercise onset, dead space ventilati-on is relatively high due to the low tidal vo-lume but decreases with increasing tidal vo-lume. This is also reflected by the trend inventilatory equivalents: At the beginning,they are relatively high and decline with in-creasing tidal volume (due to reduced deadspace ventilation and due to an improved gasexchange).


Fig. 6. Anaerobic threshold acc. to various me-thods: Top left: V-slope (Graph 5 - right Y-axis),Top right: EQO

2 (graph 6); Bottom left: RER

(Graph 8); Bottom right: PETO2 (Graph 9).

Fig. 7. Example(prior to treatment);Details see text.

Essay

With increasing exercise, the body tries toimprove oxygen utilization so that fat com-bustion declines and combustion of carbo-hydrates increases. Consequently, RER in-creases from 0.85 towards 1.0. In otherwords, more CO2 is produced per oxygenportion. This adjustment is clearly reflectedby the first break point. At a certain workrate level the additional oxygen amount isstill not sufficient to produce the requiredamount of energy. Now the body activatesits anaerobic reserves.Due to anaerobic metabolism, additional CO2is released, whereby oxygen uptake is notincreased proportionally. This results in afurther increase in CO2 release as comparedto oxygen uptake reflected at the secondbreak point.

AT determination on the basis of EQO2(Graph 6):At rest and with the onset of exercise thesubject breathes shallowly. Due to the ana-tomic dead space of 200 to 300 ml, a majorpart of the ventilation doesn't reach the alve-oli resulting in relatively high breathing equi-valents for both O2 and CO2 (also see Fig. 6,upper right corner).

Evaluation of anaerEvaluation of anaerEvaluation of anaerEvaluation of anaerEvaluation of anaerobic throbic throbic throbic throbic thresholdesholdesholdesholdesholdBefore going into details, I would like topoint out that it is often not easy or someti-mes even impossible to determine anaerobicthreshold. Often, subjects are not able to evenreach the anaerobic threshold. Although weare talking about a threshold, we have to re-alize that in fact, it is a transition area. Con-sequently, if defined by different methods,the threshold is not always at the exactly samepoint depending on the method of evalua-tion. It is therefore recommended to simul-taneously use all available methods and de-fine the point which has the best possiblematch with all methods (Fig. 6).The anaerobic threshold considerably cont-ributes to endurance capacity evaluation andaccording to Wasserman, should be approxi-mately 60% of maximum predicted oxygenuptake. Unfortunately, this has not been ac-cepted so far in different guidelines forassessment (Fritsch 1999). Instead, it is stillreferred to maximum oxygen uptake. Howe-ver, this is only valid if both anaerobic thres-holds are within the normal range and thesubject has been stressed to a maximum.

ExampleExampleExampleExampleExampleAs a summary of all the different parame-ters, graphs and trends discussed above, viewthe following example:Before treatment:Figure 7 shows the results of a patient withvalvular heart defect, aortostenosis, pulmo-nary hypertension, as well as an exercise-in-duced pulmonary shunt.

With increasing work load, tidal volume in-creases resulting in a decline in relative deadspace ventilation. This is reflected by the fallof the ventilatory equivalents. At a certaintidal volume, which is defined by thesubject's pulmonary function, the increase inventilation can only be met by breathing fre-quency. This means that from this point onthe ventilatory equivalents remain approxi-mately constant.Normally CO2 is responsible for respiratorydrive, the EQCO2 curve shows a constanttrend after reaching AT, while the EQO2 curverises due to increased ventilation. This risehas the same cause as the second break ofthe V-slope curve and can consequently beused to determine AT as well.The same applies to the FETO2 curve (PETO2respectively) in Graph 9. This parameter willalso rise at AT due to hyperventilation (withregard to oxygen - please refer to Fig. 6, bot-tom right).


Fig. 8: Example (posttreatment).Details see text.

FootnotesFootnotesFootnotesFootnotesFootnotes1 Wasserman proposes 10.3, literature gives values between 9.5 and 12; according to our experience, a value of 10.5 has proven to be suitable.2 The exact calculation also considers apparative dead space VDapp of mask or mouthpiece, as otherwise these parameters would depend on the equipment: EQO2 = VE/VO2 - VDapp*BF/VO23 see note 2: analoguous for EQCO24 Literature also supports estimation of dead space ventilation on the basis of FETCO2. However, this is not very precise, especially in patients with ventilation-perfusion disorders.5 This is the result of first model calculations I have perfomed; however, for manifestation, further examinations are required.

LiteraturLiteraturLiteraturLiteraturLiterature:e:e:e:e:

1.1.1.1.1. EschenbacherEschenbacherEschenbacherEschenbacherEschenbacher WWWWW. L., Mannina . L., Mannina . L., Mannina . L., Mannina . L., Mannina A.: A.: A.: A.: A.: Analgorithm for the interpretation of cardio-pulmonary exercise tests. . . . . Chest 97 (1990)263 - 267

2.2.2.2.2. Fritsch J., SchwarFritsch J., SchwarFritsch J., SchwarFritsch J., SchwarFritsch J., Schwarz S.: z S.: z S.: z S.: z S.: Ergospirometriein der Begutachtung. Atemw Lungenkrkh25 (1999) 117 - 137

3.3.3.3.3. JaegerJaegerJaegerJaegerJaeger-Info: -Info: -Info: -Info: -Info: Schwarz S.: Ergspirometriein der Begutachtung. SonderausgabeErgospirometrie, JAEGER (1999) 8-21

4.4.4.4.4. Johnson R. L.: Johnson R. L.: Johnson R. L.: Johnson R. L.: Johnson R. L.: Gas Exchange Efficiencyin Congestive Heart Failure. Circulation101 (2000) 2774 - 2776

5.5.5.5.5. Jones N. L.: Jones N. L.: Jones N. L.: Jones N. L.: Jones N. L.: Clinical Exercise Testing.Atemw Lungenkrkh 25 (1999) 117 -137

6.6.6.6.6. KleberKleberKleberKleberKleber F F F F F. X., . X., . X., . X., . X., VVVVVietzke G., ietzke G., ietzke G., ietzke G., ietzke G., WWWWWernecke K.ernecke K.ernecke K.ernecke K.ernecke K.D. et al.:D. et al.:D. et al.:D. et al.:D. et al.: Impairment of Ventilatory Effi-ciency in Heart Failure. Circulation 101(2000) 2803 - 2809

7.7.7.7.7. MeyerMeyerMeyerMeyerMeyer F F F F F. J., Borst M. M., Zugck C. et. J., Borst M. M., Zugck C. et. J., Borst M. M., Zugck C. et. J., Borst M. M., Zugck C. et. J., Borst M. M., Zugck C. etal.: al.: al.: al.: al.: Respiratory Muscle Dysfunction inCongestive Heart Failure. Circulation 103(2001) 2153 - 2158

8.8.8.8.8. R¸hle K.-H.: R¸hle K.-H.: R¸hle K.-H.: R¸hle K.-H.: R¸hle K.-H.: Praxisleitfaden der Spiroer-gometrie. Kohlhammer (2001)

9.9.9.9.9. Roca J., Roca J., Roca J., Roca J., Roca J., Whipp B. J. Whipp B. J. Whipp B. J. Whipp B. J. Whipp B. J. Clinical ExerciseTexting. ERS Monograph 6 (1997)

10.10.10.10.10. Schardt FSchardt FSchardt FSchardt FSchardt F., Bedel S.:., Bedel S.:., Bedel S.:., Bedel S.:., Bedel S.: Ergospirometrie inder arbeits- und sozialmedizinischenBegutachtung, Sonderausgabe Ergospiro-metrie, JAEGER (1999) 24-25

111111.1.1.1.1. WWWWWasserman K., Hansen J. E., Sue D. asserman K., Hansen J. E., Sue D. asserman K., Hansen J. E., Sue D. asserman K., Hansen J. E., Sue D. asserman K., Hansen J. E., Sue D. YYYYY.,.,.,.,.,Casaburi R., Casaburi R., Casaburi R., Casaburi R., Casaburi R., Whipp B. J.: Whipp B. J.: Whipp B. J.: Whipp B. J.: Whipp B. J.: Principles ofExercise Testing and Interpretation. Lip-pincott Williams & Wilkins, Philadelphia(1999)

Hermann Eschenbacher, Ph.D.Erich Jaeger GmbHScientific Application and Training CenterLeibnizstr. 7D-97204 Hoechberg.

+49 (0)931 4972-381, +49 (0)931 4972-319,

eMail: [email protected]

Essay

Assessment of cardiac (cardiopulmonary)Assessment of cardiac (cardiopulmonary)Assessment of cardiac (cardiopulmonary)Assessment of cardiac (cardiopulmonary)Assessment of cardiac (cardiopulmonary)performanceperformanceperformanceperformanceperformanceMaximum oxygen uptake: approx. 1,286 mLMaximum V'O2 pred = 2,119 mL reduced(approx. 61%)a) V'O2: Linear, no flattening, normal slo-pe yet no cardiac limitationb) HR: Linear increase, high HR reserve

yet no cardiac limitationc) HR/V'O2: Slightly above normal, unpro-

portional rise at the end slightly im-paired cardiac function

c) O2 pulse: Low, still increasing oxygenpulse yet no cardiac limitation butslightly impaired cardiac function

Assessment of ventilatory performanceAssessment of ventilatory performanceAssessment of ventilatory performanceAssessment of ventilatory performanceAssessment of ventilatory performancea) V'E: Continuous increase in ventilation

no ventilatory limitationb) V'E/V'CO2: Increased ventilation (both

"offset" and slope) increased ventila-tory demandVT/V'E:- Normal breathing pattern yet no

ventilatory limitation- Dynamic F/V not available but no gra-

phical indication of any ventilatory li-mitation

Assessment of a ventilation-perfusion-im-Assessment of a ventilation-perfusion-im-Assessment of a ventilation-perfusion-im-Assessment of a ventilation-perfusion-im-Assessment of a ventilation-perfusion-im-pairmentpairmentpairmentpairmentpairmenta) Impairment (Graph 4 and Graph 6): the

hardly declining ventilatory equivalents,which immediately rise after exercise on-set are important.

Suspected pulmonary shunt and dif-fusion disorder

b) Blood gases are not available but bothGraph 4 (high slope) and Graph 6 (in-creased, rising during exercise) rather in-dicate a gas exchange disorder (pulmo-nary hypertension, pulmonary shunt).

Definition of anaerDefinition of anaerDefinition of anaerDefinition of anaerDefinition of anaerobic throbic throbic throbic throbic threshold (Aeshold (Aeshold (Aeshold (Aeshold (AT)T)T)T)T)a) AT at approx. 993 mLb) AT at approx. 47 % of V'O2 pred con-

siderably reducedAfter treatment:Although the subject was not stressed to amaximum, it is clearly shown after after after after after treatment(artificial valves and surgery of aortosteno-sis) that (Fig. 8):

the lower limit of maximum oxygenuptake is reached (85% pred)oxygen pulse is within normal range(96% pred)heart rate increase is within normal ran-ge (only a small unproportional rise canbe seen at the end)diffusion disorder is no longer present(EQO2 within normal range: approx. 22at AT, even the slope in Graph 4 is low)AT is 1,495 mL and consequently withinnormal range.

Last, but not least, I would like to point outthat also the stress ECG, which is not discus-sed in this essay, may provide important in-formation for evaluation and interpretation.


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Principles of ExerPrinciples of ExerPrinciples of ExerPrinciples of ExerPrinciples of Exercise cise cise cise cise TTTTTesting & Interpresting & Interpresting & Interpresting & Interpresting & Interpretation: Including Pathophysiology andetation: Including Pathophysiology andetation: Including Pathophysiology andetation: Including Pathophysiology andetation: Including Pathophysiology andClinical Clinical Clinical Clinical Clinical ApplicationsApplicationsApplicationsApplicationsApplicationsvon Karlman Wasserman (Editor), James E. Hansen, Darryl Y. Sue, Richard Casaburiund Brian J. WhippISBN 0683306464The book is clearly structured and answers the question as to how and whycardiopulmonary exercise testing is to be performed. 83 cases are documented anddiscussed in detail. Interpretation is based on the nine-panel graph.Professor Wasserman's approach of the engaging gears illustrates the link betweenventilation, circulation and muscle work.Clinical ExerClinical ExerClinical ExerClinical ExerClinical Exercise cise cise cise cise TTTTTestingestingestingestingestingvon Norman L., MD JonesISBN 072166511XThe book provides a good survey of application, indications and contra-indications ofexercise tests. According to the respective requirementes four steps ofcardiopulmonary exercise testing are described. Recording of cardiac output accordingto the indirect Fick-method with CO2 is explained in detail. A discussion of samplecases perfectly completes the book.Clinical ExerClinical ExerClinical ExerClinical ExerClinical Exercise cise cise cise cise TTTTTestingestingestingestingestingvon J. Roca, B.J. WhippISSN 1025-448xThis describes factors limiting exercise tolerance in patients suffering from pulmonarydiseases. It provides information on how to optimize a stress test, on interpretation ofresults and improvement of exercise intolerance.ACSMíACSMíACSMíACSMíACSMís Guidelines fors Guidelines fors Guidelines fors Guidelines fors Guidelines for Exer Exer Exer Exer Exercise cise cise cise cise TTTTTesting and Presting and Presting and Presting and Presting and Prescriptionescriptionescriptionescriptionescriptionby American College of Sports Medicinevon Larry Keenney, PHD FACSM, Reed H. Humphrey PHD FACSM, Cedric X. BryantPHD FACSMISBM 0683000233New edition of a one-stop resource for the knowledge, skills and abilities needed forACSM certifications and current clinical practices in sports medicine. It emphasizesthe value and application of exercise testing and prescription in subjects with andwithout chronic disease. Expert insights cover a broad range of specialists includingphysiology, fitness, cardiology, pulmonary medicine, epidemiology, law, nursing,physician assisting and physical therapy.Manual of Clinical ExerManual of Clinical ExerManual of Clinical ExerManual of Clinical ExerManual of Clinical Exercise cise cise cise cise TTTTTesting, Presting, Presting, Presting, Presting, Prescription and Rehabilitationescription and Rehabilitationescription and Rehabilitationescription and Rehabilitationescription and Rehabilitationvon Altug, Janet L. Hoffman, Jerome L. Martin (Herausgeber), Ziya AltugISBN: 0838502415This book provides the clinically relevant components of exercise testing, prescriptionand rehabilitation in an easy-to-read format. This format features tables, figures, listsand charts. The book is written primarily for physical therapists, occupationaltherapists, athletic trainers, exercise physiologists and physical educators specializingin sports medicine and/or work hardening (i.e. industrial rehabilitation).Essentials of CardiopulmonarEssentials of CardiopulmonarEssentials of CardiopulmonarEssentials of CardiopulmonarEssentials of Cardiopulmonary Exery Exery Exery Exery Exercise cise cise cise cise TTTTTestingestingestingestingestingby Jonathan MyersISBN: 0873226364A practical guide to using gas exchange techniques in clinical and research settings,explaining exercise testing technology and its applications. After background materialon exercise physiology and cardiopulmonary responses to exercise, coverage includesinformation on calibration procedures, instrumentation, interpretation of gas exchangedata, and application of data to cardiovascular and pulmonary disorders. It lists normalvalues for exercise capacity, and gives instructions on specialized applications ofinvasive hemodynamic measurements.

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