CLINICAL STUDIES Echocardiography

Physician-Performed Point-of-CareEchocardiography Using a Laptop Platform ComparedWith Physical Examination in the Cardiovascular PatientKirk T. Spencer, MD, FACC, Allen S. Anderson, MD, FACC, Ajay Bhargava, MD,Amy C. Bales, MD, FACC, Matthew Sorrentino, MD, FACC, Kathy Furlong, RN,Roberto M. Lang, MD, FACCChicago, Illinois

OBJECTIVES The purpose of this study was to compare the results of physical examinations (PEs)performed by board-certified cardiologists with the results of point-of-care (POC) echocar-diography in a group of patients with cardiovascular disease.

BACKGROUND Although cardiovascular PE is crucial in the evaluation of patients with suspected heartdisease, the skills required to diagnose abnormal cardiovascular findings have been declining.Echocardiography is a powerful noninvasive cardiovascular diagnostic tool; however, echo-cardiographic evaluation of patients is not performed at the time of patient encounter (POCechocardiography), beacuse current platforms are cumbersome and expensive for individualphysician use. The development of miniaturized echocardiographic equipment has thepotential to overcome some of these limitations.

METHODS Thirty-six subjects had a complete cardiovascular examination by four board-certifiedcardiologists. The physicians subsequently imaged each patient using a miniaturized echo-cardiographic platform. The yield of PE and POC echocardiography were compared using acomplete echocardiographic study as the gold standard, performed on an upper-end platform.

RESULTS Cardiac examination failed to detect 59% of the overall cardiovascular findings. Physician-performed echocardiography with the prototype device missed 29% of the overall cardiovas-cular pathology. When considering only the major cardiovascular findings, the cardiologists’PEs still failed to correctly detect 43%. Point-of-care echocardiography reduced this to 21%without significant interphysician variation.

CONCLUSIONS Point-of-care echocardiography using a miniaturized echocardiographic platform substan-tially improved the detection of important cardiovascular pathology compared with PE. Useof this device by a cardiovascular specialist with training in echocardiography as a routineadjunct to PE appears to be useful. (J Am Coll Cardiol 2001;37:2013–8) © 2001 by theAmerican College of Cardiology

Cardiovascular physical examination (PE), along with pa-tient interview, forms the cornerstone of the evaluation ofthe patient with suspected heart disease. A broad spectrumof cardiovascular disorders can be detected and graded withbedside inspection, palpation and auscultation. However,the PE skills required to diagnose abnormal cardiovascularfindings have been declining. Studies assessing PE abilitieshave shown significant error and omission rates for physi-cians at all levels of training (1). This decline in PE skills has

See page 2023

been attributed to the reliance on newer technologicalmethods of diagnosis as well as decreasing availability oftime for bedside teaching (2–4).

Echocardiography is a powerful noninvasive cardiovascu-lar diagnostic tool that provides highly sensitive and specificresults. An echocardiography study is typically orderedwhen the PE or history suggests a cardiovascular disorder.The study is generally performed hours to days after thephysician-patient encounter. Echocardiographic evaluationof patients is not performed at the time of this encounter forseveral reasons. First, there is the belief that PE of thecardiovascular system is sufficiently accurate. In addition,current echocardiographic platforms are cumbersome andexpensive for individual physician use. Lastly, substantialtraining is required to obtain echocardiographic images witha full-feature echocardiographic platform.

The development of miniaturized echocardiographicequipment has the potential to overcome some of the size,expertise and cost limitations of larger platforms (5,6). Asmall, simplified echocardiographic system, the size of alaptop computer, might allow bedside evaluation of thecardiovascular patient at the time of physician encounter, socalled point-of-care (POC) echocardiography. We soughtto evaluate whether physician-performed POC echocardi-

From the Noninvasive Cardiac Imaging Laboratory, Department of Cardiology,University of Chicago, Chicago, Illinois. We thank Susan Moynihan and ToniBurkett from Agilent Technologies (Andover, Massachusetts) for their support. Wealso thank Agilent Technologies for providing the equipment used in this study.

Manuscript received August 9, 2000; revised manuscript received December 8,2000, accepted January 30, 2001.

Journal of the American College of Cardiology Vol. 37, No. 8, 2001© 2001 by the American College of Cardiology ISSN 0735-1097/01/$20.00Published by Elsevier Science Inc. PII S0735-1097(01)01288-8

ography with a miniaturized platform would provide accu-rate cardiovascular diagnoses. Specifically, we sought tocompare the results of PEs performed by board-certifiedcardiologists with the results of POC echocardiography in agroup of patients with cardiovascular disease.

METHODS

Thirty-six subjects drawn from the cardiology clinic at theUniversity of Chicago were recruited for participation inthis study. Patients were selected based on their cardiovas-cular diagnoses in order to provide a wide range of clinicalfindings that could be diagnosed by both PE and echocar-diography. In addition, six subjects without known cardio-vascular disease were enrolled. Four board-certified cardiol-ogists (with average cardiology practice experience of fiveyears) initially examined and subsequently performed trans-thoracic echocardiography with the prototype device oneach of these subjects (144 examinations). Physicians wereprovided with a brief clinical history and instructed not tointerview the patient. The cardiovascular PE was performedin a quiet office. The exam protocol and use of maneuverswere performed according to each physician’s usual practice,and their findings were recorded immediately afterward.

After completing the PE, physicians imaged each patientusing a miniaturized echocardiographic platform (Agilent

Technologies, Andover, Massachusetts). This prototypeultrasound device consisted of a base unit (27 3 20 3 8 cm),phased array 2.5 MHz transducer and battery (Fig. 1). Theweight of the assembled unit is 6.6 pounds. This platformprovides two-dimensional (2D) and color Doppler echocar-diographic images on a 14 by 10.5 cm screen. There are alimited number of controls, including those for adjustingimaging depth and gain. Images can be frozen and scrolledfor review. An electronic caliper and touch pad allowmeasurements to be performed.

No preset ultrasound exam protocol was followed, andimaging was limited to #15 min in duration. All physicianshad been trained in the use of this device and had performed10 to 15 examinations before study initiation. The physi-cians all had level II training in the performance andinterpretation of echocardiographic images. Level II train-ing, as defined by the American Society of Echocardiogra-phy, requires performing and interpreting a minimum of300 echocardiographic examinations. After completion ofthe echocardiographic study, the physicians again recordedtheir cardiovascular findings. Examples of 2D echocardio-graphic still-frames acquired with the prototype ultrasounddevice in patients enrolled in this study are depicted inFigures 2 and 3.

All subjects had a complete echocardiographic study withan upper-end platform (Sonos 5500, Agilent Technologies,Andover, Massachusetts), which served as the gold standardfor comparison. A sonographer with at least five years ofcardiovascular experience who did not have knowledge ofthe miniaturized echocardiographic results performed theseexams. Standard views were obtained, and digital loops wererecorded. No special maneuvers or agents were used toenhance the ability to detect abnormalities. A cardiologistnot involved in the patient evaluation interpreted thesestudies. The presence of mild or more severe than mildvalvular regurgitation, valvular stenosis, or right ventricular(RV) or left ventricular (LV) systolic dysfunction was noted.In addition, the presence of mitral valve prolapse or ven-tricular septal defect was recorded.Analysis. Cardiovascular findings noted on the completeechocardiographic study were recorded and divided intomajor and minor diagnoses depending on their clinicalimportance. Major findings were considered those thatwould result in further diagnostic evaluation, alter thepatient’s prognosis, require pharmacological therapy or in-dicate endocarditis prophylaxis. Specifically, this includedmoderate or more severe than moderate valvular regurgita-tion or stenosis, moderate or worse ventricular dysfunction,hypertrophic cardiomyopathy, mitral valve prolapse or ven-tricular septal defect.

The percentage of findings present on the gold standardechocardiographic examination that were also noted by PEor POC echocardiography was computed for each physicianas well as for all observers combined. Differences betweenphysicians were compared with a chi-squared test. Theyields of PE and POC echocardiography were compared

Abbreviations and AcronymsLV 5 left ventriclePE 5 physical examinationPOC 5 point-of-careRV 5 right ventricle2D 5 two-dimensional

Figure 1. Prototype miniaturized echocardiographic platform.

2014 Spencer et al. JACC Vol. 37, No. 8, 2001Physician-Performed Point-of-Care Echocardiography June 15, 2001:2013–8

with a McNemar chi-squared test. The detection rates ofindividual findings for echocardiography and PE werecompared with a chi-squared test with Yates’ correction.

RESULTS

There was a total of 79 cardiovascular findings detected bythe gold standard echocardiographic examination in thispatient population. Of these 79 findings, 34 were consid-ered to be of major clinical importance. Imaging with thedevice was easily learned and readily performed in the officesetting. Representative images are shown in Figures 2 and 3.

Cardiac examination failed to detect 59% of the overallcardiovascular findings, with all four physicians havingsimilar rates of exam failure (Table 1). Physician-performedechocardiography with the prototype device missed 29% ofthe overall cardiovascular pathology, without significantdifference among the four physicians. This 51% reduction inunnoted cardiovascular abnormalities was statistically sig-nificant. When considering only the major cardiovascular

findings, the cardiologists’ PEs still failed to correctly detect43% (Table 1). Point-of-care echocardiography reduced thisto 21% without significant interphysician variation. Thisrepresents a statistically significant 50% increase in thedetection of major abnormalities during the patient encounter.

As shown in Table 2, only 3% of the findings, whethermajor or minor, were detected by PE and missed by POCechocardiography. Both techniques considered togethermissed 26% of overall and 18% of major diagnoses. Amongthe normal patients, three of six of the PEs revealed anabnormality not present on the gold standard echocardio-graphic study. There was a total of six false positive PEfindings including: mitral regurgitation (2), mitral valveprolapse (2), tricuspid regurgitation (1) and LV dysfunction(1). Point-of-care echocardiography was abnormal in two ofsix normal subjects, with four findings: two mild mitralregurgitation, one mild tricuspid regurgitation and onemitral valve prolapse.

Among the valvular findings, there was a significant

Figure 2. Examples of still-frames obtained from two-dimensional echocardiographic studies acquired using the miniaturized echocardiographic device. (A)Parasternal long-axis view obtained from a patient with hypertensive heart disease. (B) Parasternal long-axis view obtained from a patient with rheumaticmitral stenosis. (C) Parasternal long-axis view obtained from a patient with severe sclerocalcific aortic valve stenosis and calcification of the mitral valve.(D) Parasternal long-axis view obtained from a patient with a dilated cardiomyopathy. Ao 5 aorta; LA 5 left atrium; LV 5 left ventricle; RV 5 rightventricle.

2015JACC Vol. 37, No. 8, 2001 Spencer et al.June 15, 2001:2013–8 Physician-Performed Point-of-Care Echocardiography

increase in the detection of systolic murmurs with POCechocardiography over clinical examination (Table 3). Aor-tic stenosis, mitral regurgitation and tricuspid regurgitationwere correctly detected two to four times as often withphysician-performed echocardiography compared with PE.There was also an increase in diastolic valvular lesiondetection with POC echocardiography that was primarilydue to improved aortic insufficiency diagnosis.

Physical examination identified major valvular lesionswith a similar accuracy to that of POC echocardiographywith the exception of mitral stenosis, which was nevermissed by echocardiography (Table 4). Echocardiographywas superior to PE for the identification of significantventricular systolic dysfunction and mitral valve prolapse(Table 4). Among the two patients with ventricular septaldefect, each patient was misidentified by at least one of thecardiologists whereas, using echocardiography, all four phy-sicians identified both patients’ ventricular septal defect.

Figure 3. Examples of color Doppler still-frames acquired using the miniaturized echocardiographic device. (A) Apical four-chamber view depictingmoderately severe mitral regurgitation. (B) Apical four-chamber view depicting moderate tricuspid regurgitation. (C) Apical four-chamber view depictingmoderately severe aortic insufficiency. (D) Parasternal short-axis view depicting pulmonic insufficiency. Ao 5 aorta; LV 5 left ventricle; PA 5 pulmonaryartery; RA 5 right atrium; RV 5 right ventricle.

Table 1. Frequency of Missed Overall and Major CardiovascularFindings by PE and POC Echocardiography

MD1

MD2

MD3

MD4 Overall

OverallPE 60% 56% 65% 57% 59%Echo 31%* 26%* 23%* 37%* 29%*

MajorPE 39% 31% 58% 46% 43%Echo 23% 13% 23%* 29% 21%*

*p , 0.05 vs. PE.Echo 5 echocardiography; PE 5 physical exam; POC 5 point-of-care.

Table 2. Frequency of Findings Missed by Examand Echocardiography

Echocardiography

All Findings Major Findings

1 2 1 2

Examination 1 38% 3% 54% 3%Examination 2 33% 26% 25% 18%

2016 Spencer et al. JACC Vol. 37, No. 8, 2001Physician-Performed Point-of-Care Echocardiography June 15, 2001:2013–8

DISCUSSION

PE for the evaluation of cardiovascular disease. Physicalexamination is one of the essential components of patientevaluation in medicine. In addition to the diagnostic valueof patient examination, it has served as an importantdiscriminator for the subsequent referral for more sophisti-cated, and, thus, more costly, evaluation. However, the PEskills of physicians are declining. Among the componentparts of a complete patient examination, cardiovascularexam skills have been shown to be particularly poor (7).Although cardiac auscultation has excellent specificity, thesensitivity of this technique in the current era is remarkablylow (1,4,8–13).

Cardiologists in our study identified mitral and tricuspidregurgitation murmurs in 43% and 24% of subjects, respec-tively. These results are comparable with previously pub-lished studies in which these murmurs were detected in 13%to 56% and 28% to 33% of patients, respectively (1,4,9–11).Our physicians correctly identified the murmur of aorticstenosis more often (88%) compared with prior studies inwhich this lesion was identified in only 20% to 54% ofpatients (4,10,14). The PE for the evaluation of aorticregurgitation and mitral stenosis is even poorer, with pub-lished sensitivities for the detection of diastolic murmurs as

low as 5% to 24%, which are similar to our result of 26%(4,8,11,13).

Despite the clinical importance of identifying patientswith ventricular dysfunction, our study and others havedemonstrated a limited ability for PE to diagnose decreasedRV and LV systolic performance (15). In this study, nearlytwo thirds of patients with ventricular dysfunction wentundetected with clinical evaluation alone. The poor sensi-tivity for PE findings for the detection of LV dysfunctionhas been previously noted (15). Although several examfindings are suggestive of ventricular dysfunction, they areoften difficult to illicit, and their overall sensitivity andspecificity do not allow reliable assessment of ventricularfunction (15).Echocardiography for the evaluation of cardiovasculardisease. Echocardiography often serves as the gold stan-dard in studies evaluating the accuracy of cardiac ausculta-tion. It has been speculated that cardiac ultrasound is, infact, “too sensitive” in that it detects lesions that are ofnegligible clinical importance. In this study, we omittedpatients with trivial valvular abnormalities. In addition, westratified findings according to clinical importance andshowed that PE was inaccurate even for abnormalities thatwould alter diagnostic evaluation, therapeutic plan or pa-tient prognosis.

Prior studies have demonstrated that the yield of PEimproves with the increasing severity of valvular disease.However, in this study, even when considering only themore severe grades of aortic stenosis, mitral regurgitationand tricuspid regurgitation, the PE failed to correctlyidentify these lesions in 28%, 23% and 35% of patients,respectively. These data are consistent with previous studiesdemonstrating high rates of missed diagnosis for highergrades of systolic murmurs (14% to 50% [8,9,16]).

Despite the clear superiority of echocardiography overPE, it is not used routinely during physician-patient en-counters. One of the major impediments is the high cost ofhigh-end echocardiographic systems, which typically exceed$200,000. In addition, current echocardiographic platformsare too cumbersome for practical bedside use. Moreover, inmost U.S. hospitals, sonographers, rather than physicians,perform the echocardiographic examination, which makes itimpractical to perform POC echocardiography.

In most laboratories, outpatient echocardiographic stud-ies are performed several days after the patient-physicianencounter. This results in a percentage of patients failing toreturn for the test and requires an inconvenient additionaltrip to the facility for the returning patient. The report of anechocardiographic test also takes days to return to thereferring physician. These delays preclude completion of thediagnostic evaluation and initiation of therapy at the time ofthe patient visit.POC echocardiography. This study supports the diagnos-tic utility of POC echocardiography, that is, cardiac ultra-sonography at the time of the PE performed by physicianswith prior training in echocardiography. The miniaturized

Table 3. Incidence of Selected Missed Minor Findings (Numberof Observations)

Finding

Examination Echocardiography

Missed Correct Missed Correct

AS 8 1 5 4AR 12 3 4 11*MS 2 2 2 2MR 32 26 16 42*TR 31 10 12 29*AS, PS, MR, TR 71 37 33 75*MS, AR, PR 14 5 6 13

*p , 0.05 vs. examination correct.AR 5 aortic regurgitation; AS 5 aortic stenosis; MR 5 mitral regurgitation;

MS 5 mitral stenosis; PR 5 pulmonic regurgitation; PS 5 pulmonic stenosis; TR 5tricuspid regurgitation.

Table 4. Incidence of Missed Major Findings (Numberof Observations)

Finding

Examination Echocardiography

Missed Correct Missed Correct

Aortic stenosis 2 5 1 6Aortic regurgitation 1 7 1 7Mitral stenosis 3 3 0 6Mitral regurgitation 5 16 2 19Pulmonic valve disease 1 1 2 0Tricuspid regurgitation 5 9 6 8LV systolic dysfunction 14 7 5 16RV systolic dysfunction 5 3 3 5Hypertrophic cardiomyopathy 5 1 3 3Mitral valve prolapse 7 9 2 14Ventricular septal defect 2 6 0 8

LV 5 left ventricular; RV 5 right ventricular.

2017JACC Vol. 37, No. 8, 2001 Spencer et al.June 15, 2001:2013–8 Physician-Performed Point-of-Care Echocardiography

ultrasound unit, when used by physicians, proved to besuperior to PE across all cardiovascular pathologies, includ-ing stenotic lesions, regurgitant lesions and ventriculardysfunction. The prototype device’s size and weight areclearly practical for carrying while making rounds or evalu-ating patients in a clinic. Because these platforms will proveto be substantially cheaper than current ultrasound devices,they could be owned by individual physicians, allowingimmediate and accurate evaluation of their patients’ cardio-vascular system. As with other technologies, reimbursementmay be a factor in the future use of these devices.

Although ultrasound is clearly superior for the detectionof many cardiovascular lesions, it should not replace thecardiac examination. There are several components of acardiovascular examination that yield diagnostic informa-tion that is not directly detected with echocardiography,such as jugular pulse, peripheral arterial examination, pedaledema and ventricular gallops. In addition, not all patientshave adequate acoustic windows to allow diagnostic echo-cardiographic exams. If the device and exam were bothroutinely performed, they would likely be complementary.Immediate feedback from the echocardiographic devicewould, undoubtedly, only serve to improve cardiac exami-nation skills.

Use of this device by physicians requires training in theperformance and interpretation of echocardiographic stud-ies. The physicians who participated in this study fulfilledthree years of cardiovascular education, which included fourto six months of echocardiography. In a typical cardiologyfellowship program, this would include the performance andinterpretation of several hundred echocardiograms. Use ofthis equipment by physicians without adequate trainingcould result in important omissions and misdiagnoses, withpotential adverse clinical implications. Whether cardiolo-gists with more years of clinical experience or trained at atime when greater emphasis was placed on bedside exami-nation skills would find this device to be helpful is unknown.However, our four physicians were university trained,board-certified cardiologists and likely represent the clinicalacumen of the new generation of American cardiologists.

The portable device, when used by cardiologists, stillmissed important cardiovascular findings. The reason forthis is likely multifactorial. Adult cardiologists in the U.S.do not routinely perform echocardiograms; and althoughthey are experienced in the interpretation of studies, theyhave less experience with data acquisition. In addition, moreexperience with this specific device might improve diagnos-tic yield. Another limitation is that the color Dopplercapability of the prototype device used in this study wasinitially not optimal and has been improved. Lastly, thesedevices simply do not provide image quality identical to thatof a high-end platform.

The prototype echocardiographic platform has limited

capabilities compared with upper-end platforms, which mayalso have played a role in its failure to identify certaincardiovascular lesions. Because of the limited imaging ca-pabilities, POC echocardiography cannot replace completeechocardiographic studies. The role of this device in clinicalpractice should be that of a screening instrument similar tothe stethoscope. Patients with abnormal findings should bereferred for complete echocardiographic evaluation, whichwould provide better image quality and complete hemody-namic evaluation.

Reprint requests and correspondence: Dr. Kirk Spencer,Noninvasive Cardiac Imaging Laboratory, Department of Cardi-ology, University of Chicago, 5841 South Maryland Avenue,MC5084, Chicago, Illinois 60637. E-mail: kspencer@medicine.bsd.uchicago.edu.

REFERENCES

1. Kinney EL. Causes of false negative auscultation of regurgitant lesions:a Doppler echocardiographic study of 294 patients. J Gen Intern Med1988;3:429–34.

2. Wiener S, Nathanson M. Physical examination: frequently observederrors. JAMA 1976;236:852–5.

3. Craige E. Should auscultation be rehabilitated? N Engl J Med1988;318:1611–3.

4. Mangione S, Nieman LZ, Gracely E, Kaye D. The teaching andpractice of cardiac auscultation during internal medicine and cardiol-ogy training. Ann Intern Med 1993;119:47–54.

5. Pritchett AM, Bruce CJ, Bailey KR, Tajik AJ, Seward JB. Personalultrasound imager: extension of the cardiovascular physical examina-tion (abstr). J Am Soc Echocardiogr 2000;13:485.

6. Pandian NG, Ramasamy S, Martin P, Banerjee A. Ultrasoundstecthoscopy as an extension of clinical examination during hospitalpatient rounds (abstr). J Am Soc Echocardiogr 2000;13:486.

7. Johnson JE, Carpenter JL. Medical house staff performance in physicalexamination. Arch Intern Med 1986;146:937–41.

8. Roldan CA, Shively BK, Crawford MH. Value of the cardiovascularphysical examination for detecting valvular heart disease in asymptom-atic subjects. Am J Cardiol 1996;77:1327–31.

9. Rahko PS. Prevalence of regurgitant murmurs in patients with valvularregurgitation detected by Doppler echocardiography. Ann Intern Med1989;111:466–72.

10. St. Clair EW, Oddone EZ, Waugh RA, Corey GR, Feussner JR.Assessing housestaff diagnostic skills using a cardiology patient simu-lator. Ann Intern Med 1992;117:751–6.

11. Mangione S, Nieman LZ. Cardiac auscultatory skills of internalmedicine and family practice trainees. JAMA 1997;278:717–22.

12. Grayburn PA, Smith MD, Handshoe R, Friedman BJ, DeMaria AN.Detection of aortic insufficiency by standard echocardiography, pulsedDoppler echocardiography and auscultation. Ann Intern Med 1986;104:599–605.

13. Attenhofer Jost CH, Turina J, Mayer K, et al. Echocardiography inthe evaluation of systolic murmurs of unknown cause. Am J Med2000;108:614–20.

14. Rispler S, Rinkevich D, Markiewicz W, Reisner SA. Missed diagnosisof severe symptomatic aortic stenosis. Am J Cardiol 1995;76:728–30.

15. Badgett RG, Lucey CR, Mulrow CD. Can the clinical examinationdiagnose left-sided heart failure in adults? JAMA 1997;277:1712–9.

16. Jaffe WM, Roche AHG, Coverdale HA, McAlister HF, Ormiston JA,Greene ER. Clinical evaluation versus Doppler echocardiography inthe quantitative assessment of valvular heart disease. Circulation1988;78:267–75.

2018 Spencer et al. JACC Vol. 37, No. 8, 2001Physician-Performed Point-of-Care Echocardiography June 15, 2001:2013–8