The American Journal of CA

CONGENITAL HEART DISEASE

Cardiorespiratory Response to Exercise in Ebstein’s Anomaly

GERALD BARBER, MD, GORDON K. DANIELSON, MD, CHARLES T. HEISE, C

and DAVID J. DRISCOLL, MD

Fourteen patients with unrepaired Ebstein’s anomaly underwent maximal exercise testing between Oc- tober 1982 and April 1984. Compared with control subjects, these patients had significantly lower values for total work performed, exercise time, maximal oxygen uptake, blood oxygen saturation at rest and during exercise, and heart rate and systolic blood pressure during maximal exercise.

They had a significant increase in heart rate at rest. The ventilatory equivalent for oxygen was increased significantly both at rest and during exercise. Thus, patients with Ebstein’s anomaly have decreased exercise tolerance owing to both cardiac and res- piratory limitations.

(Am J Cardiol 1985;58:509-514

Patients with Ebstein’s anomaly often have significant dyspnea and easy fatigability.1-3 One report? stated that there was no correlation between the degree of cyanosis and exercise intolerance. This claim is supported only by a retrospective study,4 based on review of the records of 3 patients after postmortem diagnosis of Ebstein’s anomaly. The precise level of exercise intolerance has not been documented by formal exercise testing. This study of patients with Ebstein’s anomaly was under- taken to determine their degree of exercise intolerance, the relation of degree of exercise intolerance to age, degree of cardiomegaly, systemic arterial blood oxygen saturation and pulmonary blood flow at rest, the effect

From the Division of Pediatric Cardiology, Section of Thoracic and Cardiovascular Surgery, and the Pulmonary Function Laboratory, Mayo Clinic and Mayo Foundation, Rochester, Minnesota. Manuscript received January 11, 1985; revised manuscript received April 15, 1985, accepted April 22, 1985.

Address for reprints: David J. Driscoll, MD, Division of Pediatric Cardiology, Mayo Clinic, 200 First Street, SW, Rochester, Minnesota 55905.

of exercise on heart rate and blood pressure, the pattern of exercise ventilation and its relation to exercise intolerance, and the incidence of arrhythmia during exercise.

Methods Patients: Patients older than 5 years who had Ebstein’s

anomaly, evaluated at our institution between October 1982 and April 1984, were included in the study. The diagnosis of Ebstein’s anomaly was established by 2-dimensional echo- cardiography and confirmed at operation in each case. No patient had significant pulmonary stenosis.

Protocol: Before exercise testing, a chest roentgenogram was taken for each patient to determine the cardiothoracic ratio.

Thirteen of the 14 patients underwent spirometry before exercise testing. The forced vital capacity, forced expiratory volume in 1 second and maximal voluntary ventilation were measured.

Heart rate, respiratory rate, electrocardiogram, blood pressure, oxygen consumption, carbon dioxide production and minute ventilation were measured at rest and during each

509

510 EXERCISE AND EBSTEIN’S ANOMALY

TABLE I Results of Exercise Testing

Blood Oxygen Saturation (%) Exercise i@

Age Total Work Exercise tio2 max, Heart Rate ~ Pt (vr) (kpm)’ Time (min)’ (liters/min)*~+ Rest Exercise min/m*)t (beats/min)* \io~ max

368 (17%) 1,012 (35%)

514 (18%) 1,042 (27%)

748 (15%) 1,777 (19%)

21022 (21% j 3,536 (32 %) 1,042 (17%) 4,413 (71%) 2,022 (13%)

2.0 (28%) 4.2 (55%) 2.8 (36%) 4.0 (49%) 3.4 (37%)

4.0 (38 %)

0.418 (37%) 0.643 (48 %) 0.496 (41%) 0.785 (51%) 0.541 (27%) 1.162 (48%) 0.772 (41%) 0.392 (26%) 0.949 (48%)

75 92 72 66 84

95 80 91

1.100 (39%j 1.500 (55%) :: 0.407 (18%) 90 1.900 (88%j 98 0.900 (29%) 86

42 84

56q 65

2.3

i:9 1.1

::; 2.0 0.9 1.8

::: 2.6 3.5 14

169 (89%) 69 139 (72%) 43 141(73%) 164 (83%) :f 119 (63%) 72 145 (74%j 46

163 (87%) 134 (67%) 2 162 (82%) 51 162 (82%j 175 (91%) 2

141 (71%) 187 (94%) Ef 180 (91%) 69

l In parentheses, percentage of predicted normal based on sex, height and body surface area. + Maximal oxygen uptake. t Pulmonary blood flow at rest. ! Minute ventilation divided by oxvoen uptake during maximal exercise. 11 intact atrial septum. - _-

workload during the exercise test. Three electrocardiographic leads were monitored at all times and a 12-lead electrocardi- ogram was recorded at rest and at each workload. Blood pressure was measured by using a programmable air com- pression cuff system (Narco Systems PE-300) with a cuff of appropriate sizes5 Mixed expiratory oxygen and carbon dioxide were measured with a mass spectrometer (Centronic 200 MGA). Flow was measured as expired gas passed through a pneumotachograph (Fleisch no. 3) connected to a pressure transducer (Validyne DP 45). Volume was measured by electronically integrating the flow signal. Blood oxygen sat- uration was measured by an ear oximeter (Hewlett-Packard no. 47201 A). An acetylene-helium rebreathing technique was used to measure the pulmonary blood flow in 13 of the 14 patients at rest, seated on the cycle ergometer.6

Exercise was performed on a previously calibrated cycle ergometer (Siemans-Elema 380 B) according to the protocol described by James et a1.7 Only tests that were believed to represent a maximal effort were included in the study.

Data analysis: The results of the exercise tests were ana- lyzed by comparing them with the normal values previously published by James et a17g8 and with the values from 22 control subjects in our laboratory. (For the 22 control subjects mean values were: age, 12 years; weight, 51 kg; height, 156 cm; and body surface area, 1.45 m2.)

Statistical analysis: The 2-tailed unpaired Student t test, Fisher’s exact probability and linear regression were used in statistical analysis. A p value <0.05 was considered significant. All data are expressed as mean f standard deviation.

Results Clinical features: Fourteen patients (10 female, 4

male) with Ebstein’s anomaly underwent maximal ex- ercise testing during the period of the study. They were 7 to 23 years old (mean 14). Mean weight was 48 kg, height 156 cm and body surface area 1.45 cm2. Weight, height and body surface area were not sig- nificantly different between patients and control subjects.

Two of the patients had undergone a previous Waterston shunt procedure and 2 others had had a Glenn shunt. Three of these operations were performed in the neonatal period and the fourth was performed

before age 3 years. Thirteen of the 14 patients had either an atria1 septal defect or a patent foramen ovale.

Four patients had first-degree atrioventricular block and right bundle branch block, 2 had first-degree atrioventricular block and ventricular preexcitation, 1 had first-degree atrioventricular block alone, 2 had right bundle branch block alone and 2 had ventricular preexcitation alone.

Spirometry: Maximal voluntary ventilation was 96 f 14% of predicted normal and forced vital capacity was 85 f 16% of predicted normal. The 4 patients who had previously undergone thoracotomy had a significantly (p <0.005) lower forced vital capacity (68 f 9% of pre- dicted normal) than the 9 patients who had not under- gone thoracotomy (93 f 12%). The ratio of forced ex- piratory volume in 1 second to forced vital capacity was 90 f 8%; only 1 of the 13 patients who underwent preexercise spirometry had a ratio of less than 80%.

Exercise capacity: All patients exercised to ex- haustion as indicated by audible ventilation and in- ability to maintain a pedaling frequency of 60 rpm. No patient had chest pain, syncope or other adverse effect from exercise testing.

Table I is a summary of the results of exercise testing for the 14 patients. Total work performed ranged from 6 to 71% of predicted normal. In 13 of the 14 patients, total work performed was less than 65% of predicted normal, which is the lower limit of normal in our labo- ratory. Maximal power achieved ranged from 23 to 86% of predicted normal. The lower limit of normal for maximal power in our laboratory is 70% of predicted normal; this level was achieved by only 3 of the 14 pa- tients. Total exercise time ranged from 14 to 85% of predicted normal. Only 1 of the 14 patients exercised to at least 75% of predicted normal, the lower limit of normal for our laboratory. Maximal oxygen uptake ranged from 18 to 88% of predicted normal. Only 1 of the 14 patients achieved 80% of predicted maximal oxygen uptake, the lower limit of normal for our laboratory. As percentages of predicted normal, mean total work per-

September 15. 1985 THE AMERICAN JOclRNAi OF CARDIOLOGY Volume 56 5<1

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FIGURE 1. Relation between blood oxygen saturation and total work, expressed as percentage of predicted normal, for patients with Ebstein’s anomaly. Left, at rest: % = 1.1 (saturation at rest) -63; r = 0.58, p <0.05. Right, during exercise: % = 0.85 (saturation during exercise) -33; r = 0.76; p <0.005.

formed (28 f 18%), mean maximal power achieved (55 f 20%), mean total exercise time (47 f 19%) and mean maximal oxygen uptake (43 f 17%) were all significantly (p <O.OOl) lower than the values in the 22 control subjects.

Effect of age on exercise tolerance: No correlation was found between age at time of test and exercise tol- erance (r = 0.22, p = 0.46) for the 14 patients with Eb- stein’s anomaly.

Degree of cardiomegaly and exercise tolerance: The cardiothoracic ratio ranged from 0.44 to 0.74 (mean 0.6 rt: 9). There was no correlation between cardiotho- racic ratio and exercise tolerance (r = -0.09, p = 0.74).

Degree of hypoxemia and exercise tolerance: Blood oxygen saturation was measured in 12 of the 13 patients with Ebstein’s anomaly who had an interatrial communication. All bad hypoxemia at rest and during exercise. Mean arterial oxygen saturation at rest (85 f 10%) and during exercise (70 f 16%) were significantly (p <O.OOl) lower for these patients than for control subjects. The patient with an intact atria1 septum had no hypoxemia either at rest or during exercise. Blood oxygen saturation both at rest and during exercise correlated positively with exercise tolerance (Fig. 1).

Pulmonary blood flow and exercise tolerance at rest: When measured at rest in 13 of the 14 patients, pulmonary blood flow ranged from 0.9 to 3.5 liters/ min/m2 (mean 1.8). Exercise tolerance correlated pos- itively with pulmonary blood flow at rest (Fig. 2).

Heart rate and blood pressure response: Heart rate at rest ranged from 70 to 171% of predicted normal. The normal range heart rate at rest in our laboratory is 70 to 130% of predicted normal for age. Four of the 14 patients had a heart rate at rest that exceeded the upper limit of normal and 2 had a heart rate at rest below the lower limit of normal. Mean heart rate at rest was sig- nificantly (p <O.Ol) greater for patients (115 f 26% of predicted normal for age) than for control subjects.

Maximal heart rate during exercise ranged from 63 to 94% of predicted normal. Six of the 14 patients had a maximal heart rate during exercise of less than 80% of predicted normal, the lower limit of normal for our laboratory, Mean maximal heart rate during exercise (80 f 10% of predicted normal) was significantly (p <O.OOl) less than that for control subjects.

Mean systolic blood pressure at rest (92 f 7% of predicted normal) and diastolic blood pressure (102 f 17% of predicted normal) were similar to those of control subjects. No patient had a systolic blood pressure at rest outside the range of normal for our laboratory. Two of the 14 patients had a diastolic blood pressure at rest exceeding the normal value for their age. Systolic blood

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Pulmonary blood flow, L/min/m 2 FIGURE 2. Relation between pulmonary blood flow index at rest and total work performed, expressed as a percentage of predicted normal, for patients with Ebstein’s anomaly. % = 17.2 (pulmonary blood flow index at rest) -4.2; r = 0.66, p X0.01.

512 EXERCISE AND EBSTEIN’S ANOMALY

pressure during exercise ranged from 65 to 96% of pre- dicted normal. Seven patients had a systolic blood pressure during exercise of less than 75% of predicted normal, the lower limit of normal for our laboratory. Mean systolic blood pressure during exercise (76 f 10% of predicted normal) was significantly (p <O.OOl) less than that of control subjects. Mean diastolic blood pressure during exercise (95 f 19% of predicted normal) was not significantly different from that of control subjects. However, 4 patients had a diastolic blood pressure during exercise that exceeded the upper limit of normal for our laboratory; 1 of these was 1 of the 2 patients who had an increased diastolic blood pressure at rest.

Exercise ventilation: The ventilatory equivalent for oxygen was significantly greater for patients with Eb- stein’s anomaly than for control subjects, both at rest and during exercise (Fig. 3). The ratio of minute venti- lation at rest to maximal voluntary ventilation at rest was significantly greater (p <0.05) in patients with Ebstein’s anomaly (15 f 4%) than in control subjects (11 f 5.3%) (Fig. 4). However, the ratio of minute ventila- tion during maximal exercise and maximal voluntary ventilation at rest was significantly (p <O.Ol) lower in patients (52 f 14%) than in control subjects (68 f 17%). This occurred because patients with Ebstein’s anomaly had a lower maximal oxygen uptake than did control subjects. For any given level of oxygen uptake, patients had a greater ratio of minute ventilation to maximal voluntary ventilation than did control subjects. For patients with Ebstein’s anomaly to have achieved the same level of oxygen uptake as control subjects, they would have had to exceed their maximal voluntary ventilation.

Exercise electrocardiography: No exercise tests were terminated because of an arrhythmia. Four pa- tients showed preexcitation on their electrocardiogram at rest. There was no statistically significant difference

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Rest Exercise FIGURE 3. Mean (A standard deviation) ventilatory equivalent for oxygen at rest and during exercise (V,/V,,, for 14 patients with Ebstein’s ~no<mrn;~ line) and 22 control subjects (solid line). l p <0.05;

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in exercise tolerance between these 4 patients with and the 10 patients without preexcitation. One of the pa- tients with preexcitation had supraventricular tachy- cardia (170 beats/min) during exercise. There were no complications from this tachycardia and it reverted spontaneously after exercise. The delta wave disap- peared during exercise in another patient with preex- citation. It returned with slowing of heart rate after exercise. A third patient with ventricular preexcitation had a brief episode of ventricular bigeminy 2 minutes, after completion of exercise. One of the patients without preexcitation had bigeminy during exercise and this resolved after exercise. Because of the presence of either preexcitation or right bundle branch block, ST-segment changes could not be evaluated in 11 of the patients. In the 3 patients in whom ST segments could be evaluated, no ST-segment depression was seen either at rest or during exercise.

Discussion Estimates of exercise tolerance overestimate mea-

sured capacity in children. g-11 Therefore, detailed ex- ercise testing is necessary for adequate evaluation of the exercise tolerance of children with congenital heart disease. Exercise testing also is helpful in evaluating patients’ responses to various therapeutic interventions.

Exercise tolerance: This study shows that patients with Ebstein’s anomaly have a significant reduction of exercise tolerance that is unrelated to age. The inability to show an effect of age on exercise tolerance-unlike that reported by Driscoll et all2 in patients with “functional single ventricle”-may be a result of the wide spectrum of severity of Ebstein’s anomaly and small sample size. It is unknown whether patients with Ebstein’s anomaly would show a progressive decline

100 I

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FIGURE 4. Relation between minute ve?tilation, expressed as per- centage of maximal voluntary ventilation (VJMVV), and oxygen uptake (vo,), expressed as percentage of predicted maximal oxygen uptake (V,, max), for patients with Ebstein’s anomaly (broken line) and control subjects (solid line) at rest and during exercise. Results are mean f standard deviation. * p <O.OOl.

in exercise tolerance with increasing age if tested serially.

The degree of cardiomegaly in Ebstein’s anomaly is correlated with survival.1>3 The degree of cardiomegaly was not correlated with exercise tolerance in this study. However, most of our patients had marked cardio- megaly and only 3 had a cardiothoracic ratio of less than 0.55. Thus a relation between cardiothoracic ratio and exercise tolerance may exist, but was not apparent in this study because few patients had mild disease.

The reduction in exercise tolerance was related to systemic arterial blood oxygen saturation both at rest and during exercise and to pulmonary blood flow at rest. This correlation between exercise tolerance and pul- monary blood flow is similar to that shown for cyanotic patients with tetralogy of Fallotg and functional single ventricle.12

Heart rate and blood pressure response during exercise: Our patients with Ebstein’s anomaly had tachycardia at rest. A similar tachycardia at rest has been noted in patients with tetralogy of Fallot.rO This tachycardia may represent an adaptation to maintain tissue oxygen supply in the presence of chronic hypox- emia. The maximal heart rate during exercise was sig- nificantly less than in control subjects. It has been shown that hypoxia may decrease the maximal heart rate response to exercise.i3J4 Patients with tetralogy of FallotgJ1 and functional single ventriclei have a similar blunted heart rate response to exercise. In our patients with Ebstein’s anomaly, however, there was no corre- lation between heart rate during maximal exercise and systemic arterial blood oxygen saturation during exer- cise (r = 0.27, P = 0.37). Thus, hypoxemia probably is not the only cause of the blunted heart rate response to exercise in patients with cyanotic congenital heart disease.

Unlike patients with functional single ventricle,i2 patients with Ebstein’s anomaly have a significantly decreased blood pressure response to exercise. However, because patients with Ebstein’s anomaly and patients with functional single ventricle have similar reductions in heart rate during maximal exercise, the abnormal blood pressure response must be the result of reduced stroke volume response or an abnormally reduced sys- temic vascular resistance in patients with Ebstein’s anomaly. This may be the result of interference with cardiac output during maximal exercise, caused by significant tricuspid insufficiency with either a restrictive atria1 septal defect or an intact atria1 septum.

Exercise ventilation: Similar to results of previous studies of patients with tetralogy of Falloti0J1~r5 and functional single ventricle,12 we find that patients with Ebstein’s anomaly ventilate excessively, both at rest and during exercise. This hyperventilation has been attributed to a true or relative hypercapnia by Shephard. ls He found a decreased carbon dioxide concentration in arterial blood but increased concen- trations in tissue. Strieder et ,117 found increased dead space ventilation and increased arterial-alveolar gra- dient for partial pressure of carbon dioxide in patients with cyanotic congenital heart disease. They believed

that this :inability to eliminate ca:rbon dioxide appro- priately ma,y result in stimulation. of an already over- worked respnatory (center and interference with buf- fering of the lactic acid produced during exercise.

The forced vital capacity was abnormal in 5 of the 14 patients. Patients with tetralogy of Fallotg and func- tional single ventricl.e12 have decreased forced vital capacity. This may represent restrictive lung disease from prior thoracotomy or from pulmonary congestion (patients with aortopulmonary anastomosis) or both. Four of the 5 patients in this study who had decreased forced vital capacity has previously undergone thora- cotomy (p <0.005).

Exercise electrocardiography: Exercise testing may be useful in provoking and documenting supra- ventricular tachycardia in patients with Ebstein’s anomaly who have a history suggestive of tachycardia. Supraventricular tachycardia was provoked by exercise testing in 1 of 4 patients with Ebstein’s anomaly and ventricular preexcitation. Whether supraventricular tachycardia can be provoked consistently by exercise in some patients and whether, in these patients, exercise testing can be used to evaluate response to antiar- rhythmia therapy is unknown,

Conclusions: Patients with Ebstein’s anomaly have a significantly decreased exercise tolerance. A combi- nation of cardiac, respiratory and metabolic factors probably accounts for this severe limitation. Besides an abnormality of the tricuspid valve, patients with Ebstein’s anomaly frequently have abnormalities of the right ventricular myocardiumrs and of left ventricular function.1g~20 Peripheral tissue oxygenation may be limited because of decreased pulmonary blood flow and the presence of a right-to-left shunt in patients with an interatrial communication. Hyperventilation at rest and during exercise imposes an additional workload on cy- anotic patients with Ebstein’s anomaly, which con- tributes to limited maximal oxygen uptake and exercise intolerance.

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2.

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5.

8.

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a. 9.

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11.

References

Kumar AE, Fyler DC, Miettinen OS, Nadas AS. Ebstein’s anomaly: clinical profile and natural history. Am J Cardiol 1971;28:84-95. Watson H. Natural history of Ebstein’s anomaly of tricuspid valve in child- hood and adolescence: an international co-operative study of 505 cases. Br Heart J 1974;36:417-427. Gluliani ER, Fuster V, Brandenburg RO, Mair DD. Ebstein’s anomaly: the clinical features and natural history of Ebstein’s anomaly of the tricuspid valve. Mayo Clin Proc 1979;54:163-173. Engle MA, Payne TPB, Bruins C, Taussig HB. Ebstein’s anomaly of the tricuspid valve: report of three cases and analysis of clinical syndrome. Circulation 1950;1:1246-1260. Blumenthal S. Report of the Task Force on blood pressure control in chil- dren. Pediatrics 1977;suppl:59:797-820. Trlebwasser JH, Johnson RL Jr, Burpo RP, Campbell JC, Reardon WC, Blomquist CG. Noninvasive determination of cardiac output by a modified acetylene rebreathing procedure utilizing mass spectrometer measure- ments. Aviat Space Environ Med 1977;48:203-209. James FW, Kaplan ST Glueck CJ, Tsay J-Y, Knight MJS, Sarwar CJ. Re- sponses of normal chrldren and young adults to controlled bicycle exercise. Circulation 1980;61:902-912. James FW. Exercise testing in normal individuals and patients with car- diovascular disease. Cardiovasc Clin 1981;i 1:227-246. Crawford DW, Simpson E, Mclkoy MB. Cardiopulmonary function in Fallot’s tetralogy after palliative shunting operations. Am Heart J 1967;74:463- 472. Gold WM, Mattioli LF, Price AC. Response to exercise in patients with tetraology of Fallot with systemic-pulmonary anastomoses. Pediatrics 1969;43:781-793. Erlksson BO, Bjarke B. Oxygen uptake, arterial blood gases and blood lactate concentration during submaximal and maximal exercise in adult subjects with shunt-operated tetralogy of Fallot. Acta Med Stand 9975;

514 ANATOMIC CORRECTION OF TRANSPOSITION OF THE GREAT ARTERIES

197:187-193. 12. Driscoll DJ, Staals BA, Heise CT, Rice MJ, Puga FJ, Danielson GK, Ritter

DG. Functional single ventricle: cardiorespiratory response to exercise. JACC 1984;4:337-342.

13. Burgh Daty M, Scott MJ. The effect of hypoxia on the heart rate of the dog with special reference to the contribution of the carotid body chemore- ceptors. J Ph

14. Astrand PO, siol (Land) 1959;145:440-446.

x strand I. Heart rate during muscular work in man exposed to prolonged hypoxia. J Appl Physiol 1958;13:75-80.

15. Edelman NH, Lahiri S, Braudo L, Cherniack NS, Fishman AP. The blunted ventilatory response to hypoxia in cyanotic congenital heart disease. N Engl J Med 1970;282:405-411.

16. Shephard RJ. The resting hyperventilation of congenital heart disease. Br Heart J 1955;17:153-162.

17. Strieder DJ, Mesko ZG, Zaver AG, Gold WM. Exercise tolerance in chronic hypoxemia due to right-to-left shunt. J Appl Physiol 1973;34:853-858.

18. Anderson KR, tie JT. The right ventricular myocardium in Ebstein’s anomaly: ;8orphometrrc histopathologrc study. Mayo Ckn Proc 1979;54:181-

19. Monibi AA, Neches WH, Lenox CC, Prak SC, Mathews RA, Zuberbuhler JR. Left ventricular anomalies associated with Ebstein’s malformation of the tricuspid valve. Circulation 1978;57:303-306.

20. Ng R, Somerville J, Ross D. Ebstein’s anomaly: late results of surgical correlation. Eur J Cardiol 1979;9:39-52.

Influence of the Two-Stage Anatomic Correction of Simple Transposition of the Great Arteries

on Left Ventricular Function

HANS H. SIEVERS, MD, PETER E. LANGE, MD, DIETRICH G.W. ONNASCH, PhD, ROSEMARY RADLEY-SMITH, MD, MAGDI H. YACOUB, FRCS, PAUL H. HEINTZEN, MD,

DIETER REGENSBURGER, MD, and ALEXANDER BERNHARD, MD

To evaluate the influence of the 2-stage anatomic correction of simple transposition of the great ar- teries on left ventricular (LV) function, pressure and angiocardiographic volume data were analyzed during resting conditions shortly before banding of the pulmonary trunk (n = 12) and before (n = 17) and after anatomic correction (n = II), and com- pared with data from controls (n = 12). Age at banding and anatomic correction was between 1 and 44 months (mean 16 f IO) and between 13 and 47 months (mean 24 f IO), respectively. The in- terval between anatomic correction and the inves- tigation ranged from 10 to 29 months (mean 20 f 7). Afler banding, LV ejection fraction decreased (p <O.Ol) and LV peak systolic pressure (p <O.Ol) as well as LV end-diastolic pressure (p <0.05) in- creased. After anatomic correction, these variables

and LV end-systolic wall stress were not significantly different from control values. The LV end-systolic wall stress-ejection fraction relation in 7 of 11 pa- tients after anatomic correction was within control range. The highest values were found in the youn- gest patients at banding and at anatomic correction. In contrast to measures of global myocardial func- tion, such as LV ejection fraction and LV end-dia- stolic pressure data, the LV end-systolic stress- ejection fraction relation suggest that LV function may not be normal in some patients 20 months after anatomic correction. Young age at operation, however, appears to be advantageous in preserving LV function. Hemodynamic alterations after banding probably reflect LV adaptation to systemic pressures in a hypoxemic circulation.

(Am J Cardiol 1965;56:514-519)

Anatomic correction provides a logical and direct method of treatment for transposition of the great ar- teries.1*2 Its potential limitations have been reported.2 One of them relates to the fate of left ventricular (LV) function, especially in patients with simple transposi- tion. In these patients, a rapid diminution of LV muscle

From the Departments of Cardiovascular Surgery and Pediatric Cardi- ology of the University of Kiel, Kiel, Federal Republic of Germany, and Harefield Hospital, Harefield, Great Britain. Manuscript received Sep- tember 6, 1984; revised manuscript received March 21, 1985, accepted April 25, 1985.

Address for reprints: Hans-Hinrich Sievers, MD, Department of Cardiovascular Surgery, University of Kiel, Hospitalstrasse 40, D-2300 Kiel, Federal Republic of Germany.

mass occurs soon after birth, depending on the decrease in pulmonary vascular resistance,3 leaving the left ventricle incapable of supporting the systemic circula- tion.2y4 Redevelopment of the left ventricle by banding of the pulmonary trunk has proved effective in pre- paring it for anatomic correction.5p6 Both surgical stages alter LV load and may affect LV function. In this study we attempted to increase knowledge of the behavior of LV function during and after this 2-stage procedure by analyzing pressure and angiocardiographic volume data in our patients shortly before banding (n = 12) as well as before (n = 17) and after anatomic correction (n = 11). Values were compared with those of 12 control subjects.