JACC Vol. 20. No. 2 August 1992:295-300

295

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Tetralogy of Fallot is the most common form of cyanotic congenital heart disease. Although primary intracardiac repair for tetralogy of Fallot currently has an operative mortality rate as low as 0% to 5% (1,2), the long-term success is compromised by the occurrence of late sudden cardiac death in pediatric and adolescent patients (3-6). Controversy exists as to the cause of sudden death Some investigators (4,6) attribute sudden death in these patients to ventricular arrhythmias and tachyarrhythmias (7). Other investigators (8,9) suggest that heart block secondary to intracardiac repair may contribute to sudden death. To date, most of the follow-up studies in patients with repaired tetralogy of Fallot have involved children or adolescents. The long-termfollow-up findingsfor this operation

in adults are less established and may d&r significantly from those in younger patients. Accordingly, we followed up a cohort of ISI adult patients with repaired tetra ogy of Fallot and p~ospe studied their clinical outcome and factors pot ing their survival. A palliative procedure ( patients, Potts in 2 and Waterston in 3) had been performed in 84 patients (56%) before repair. We performed serial noninvasive studies to evaluate the prognostic value of previously identified risk factors for sudden death in this cohort. Of the 151patients, a subgroup of 36 patients have undergone three sets of noninvasive follow-up studies to examine the temporal changes of these variables over a significantperiod of time.

From the Toronto Congenital Cardial~ Cantre for Adults, Division of Cardiology, Toronto General Division, The Toronto Hospital, University of Toronto, Ontario, Canada. This study was supported by Grant T-1494 from the Heart and Stroke Foundation of Ontario, Toronto. Dr. Liu is a Research Scholar with the Heart and Stroke Foundation of Canada, Ottawa, Ontario. Manuscript received March 13, 1991; revised manuscript received February 13, 1992, accepted March IO, 1992. -for Peter R. McLaughlin, MD. Sirision of Cardiology, Eaton 12-224, Toronto General Hospilai, 200 Elizr eth Streei. Toronto, Ontario, Canada MSG 2C4.

ts. The Congeniial Cardiac Centre at The ospital, University of Toronto follows up adult patients with congenital heart disease in the Ontario, most of whom are referred Sick Children a,ft.er18 years of age. and May 1989,151patients were entered in the registry and follow-up program for adults with repaired tetralogy of Fallot at the Congenital Cardiac Centre. A sn.?bsetof 36

01992 by the American College of Cardiology

073% 1097/92/$5.00

WAIEN ET AL. ADULTS WITH REPAIRED

296

Table 1.

TETRALOCY

JACC Vol. 20, No. 2 August 1992:295-300

OF FALLOT

Follow-UpDemographics Padents(no.)

Follow-UpPeriod

Baseline 3 Yeats 6 Years

Male

Female

Total

87 62 19

64 48 17

110 36

I51

patients (19 male and 17femalej-fromthis cohort underwent serial testing at baseline (entry into the follow-upprogram) and at 3 and 6 years after entry (Table I). The protocol consisted of 24-h Holter electrocardiographic (ECG) monitoring, maximal symptom-limitedexercise stress ECG testing, rest and exercise radionuclide angiographyat 3.year intervals as well as right heart cathe* terizationduring the firstfollow-up(baseline)study. Patients continued to take any required medications during the tests. Studies were performed in accordance with the directives of the Helsinki Agreement (IO)and written informed consent was obtained before all studies. C%nicalfollow-up. Patients were assessed clinically at yearly intervals for functional status, symptomatic complications, medications and physical examination to rule out significantclinical deterioration or changes. Right heart catheterization. Right heart catheterization was performed by using a Swan-Ganz flotation catheter inserted into the pulmonaryartery by the right femoral route at the time of the initial follow-up (baseline) examination; this study was repeated at later exhrninationsonly if clinically indicated. Cnrdinc outhit, determined by the thermodilulion technique, was cnlculated as the mean of three consecutive measurements at rest with the use of a dedicated cardiac output computer (Electronicsfor Medicine).Pressures from the pulmonary artery wedge position, main and branch pulmonary arteries, right ventricle, right atrium and venae cnvae were recorded. Intracardiacand femoral artery blood samples were obtained for oximetry to detect residual intracardiac shunts. Ambulatory ECG monitoring. Twenty-four-hourcontinuous ambulatory ECG Holter monitoring with modified chest leads V, and Vs was performed by using series 4:24 (oxford Medical Systems) casseit: tape recorders. The tapes were analyzed by trained technicians using a Pathfinder high speed ECG analyzer (Reynolds Medical) to quantitate and classify atrial and ventricular arrhythmias. Complex ventricidar premature beats or repetitive ventricukar beats and atrial arrhythmias were categorized (IS fillow~: grade 1 = no ventricularpremature beats; grade 2 =

50 mm Hg. ssio Comparisonof orbidity and mortalitywith studiesof tetralogyof Faliot. In our study, there was a low morbidity rate, which may be related to our policy of early aggressivetreatment and correction of hemodynamic abnormalities, allowing patients to have minimal activity limitations with few residual symptoms. The low rate may also reflectthe natural history of patients with corrected tetralogy of Fallot who reach adulthood. Currently published data (12)on the follow-up of patients who have had intracardiac repair for tetralogy of Fallot

Table5. ExerciseDurationandRightand Left Ventricular QectionFractionin the TotalStudyGroup(n = 151) Mean 2 SD Exercise duration on stress testing (min)

9.3 * 2.1

RVEF on radionuclide angiography (%) Rest

34.7 + 10.3

Exercise

34.7 k 12.3

LVEF on radionuclide angiography (%) Rest Exercise LVEF tively.

and RVEF

= left and right ventricular

Table7. Frequency of ArrhythmiasRecorded on Exercise ElectrocardiographicMonitoringin the Subgroup(n = 36) Follow-Up Arrhythmia

Grade

Baseline

3 Years

6 Years 2

I

0

I

58.5 + 11.4

2

2

0

1

62.8 + 12.9

3t4

7

7

3

9

8

6

ejection fraction, respec-

AU mades

Data indicate number of patients.

JACC Vol. 20, No. 2

WAIEN REPAlRED

70

*

P=O.@Ol

9

ET AL. FALLOT

299

IL

Baseline

60

g

TETRALOGY OF

*

4Q

I& w 30 20 IO 0 BASELINE

3 YEAR FOLLOW-UP

6 YEAR FOLLOW-UP

e 3. Right ventrAar ejection fraction measured by radionuangiograpir; at rest and duringexerciseover the folallow-up

arrhythmias and conduction defects was low and that it 7). This observation is in agreesh et al. (W, who found no late

period(mean-I-SQj.A statisticallysignificantincreaseil?ejection fractionis seen during exerciseat the 3-and 6-year follow-up (p = 0.001). A trend toward an increase in ejection fraction rest is seen but is not statistically

significant.

shows that 90% will live to age 15 years, and it is estimated that 70%will live to age 30 years, Our follow-updata su that tRe overall mortality rate is low for patients with repaired tetralogy of Fallot who have reached 1Xyears of age. Our mortality rate from all causes was lower than 9 death/patient-year). Fu~bermore, the cause ofdeath in two patients was not related to the heart and there -wereno sudden cardiac deaths. There may be several important reasons for the low mortality rate observed in our adult patients. First, it is likely that the natural history of postoperative tetralogy of Fallot is such that patients with significant hemodynamic abnormalities will die first, followed by those with death due to arrhythmias. Patients who survive to 30 years of age will Left ventricular ejection fraction measured by radionuelide angiography at rest and during exerciseover the follow-up period(mean+ SD).A statistically significant decrease in ejection fraction (BF)is seen at rest (p = 0.003) and during exercise(p = 0.015). 100 90

* P=O.M)3

vb Baseline

t P=O.O15

vs Emelk

80 t

22

t

T

*

60

r;:

50

w

40 30 20 IO l-l BASELINE FOi_%?“P

F0z%-iJP

t

-

rrhythmias on 24-h Helter that the observed arrhyt were stable over time in these patients and showed no deterioration (Tab1

arrhythmias may lose significance a marker of suddec death after total repair as the patie rows into adulthood. Our results differfrom those of ot foollow-up studies of younger patients for several reasons. study group and the interval after c ctive intracardiac repair. All patients in our study were adults and the ventricular arrhythmias and sudden death that were frequent in the younger age group no longer ad the same prevalence.In our previous follow-up study, urns et al. (13) showed that arrhythmias in these patients were mainly related to hemodynamic abnormalities. Treatment of correctable hemodynamic abnormalities may have led to a decrease in the number of arrhythmias. Finally, the natural history after total repair may be such that the stability of rhythm improves as the years after repair increase. Exerciseclarati~_?n and exerei~-induced arr ercise intolerance after intracardiac repair has been asso ated with poor results (14-17). In contrast, our patielits h good exercise tolerance and functional status, which probably also contributed to their favorable outcome. Furthermore, in our subgroup of 36 patients, exercise tolerance also did not change significantlyover time (Table B),suggesting a stable level of cardiopulmonaryadaptation. This observation is compatible with our patients’ generally active life-style, with several performing a regular exercise program. Exercise-inducedarrhythmias were infrequent and their rate did not change during the follow-up period. ~ent~~cw~ar ~~~~t~o~. In our subgroup of 36 patients, serial ventricular function studies showed an improvement in right ventricular ejection fraction during exercise and a

300

WAIEN ET AL. ADULTS WITH REPAIRED TETRALOGY OF FALLOT

~10~ but definite decrease in left ventricdar ejeCtiOn ikiCti0n during both rest anti exercise over the follow-upperiod (Fig. 4 and 5). These findings differ from those of Reduto et al. (18),whose patients demonstrated abnormal right ventricular performance at rest and exercise and a normal left ventricular performance and exercise reserve: however, their study was performed only once and therefore did not address serial changes over time. Rosing et al. (1% ais0 found normal left ventricular performance and exercise reserve, Our study did not demclnstrate left ventricular dysfunction; however, long-term trends indicate that, in contrast to right ventricularejection fraction, left ventricular ejection fraction may continue to decrease with time. This observation may be attributed to the comparatively older age of our study patients (mean 28 years; range 18 to 42). It is known (20) that left ventricular ejection fraction graduallydecreases as patients age. The average age in the study of Redut0 et al. (18)was 10years (range 1 to 16). In contrast, Borow et al. (21)found latent left ventricular dysfunction on postoperative catheterization 1 year after repair, but the patients were in the pediatric age group. Using cineangiographic techniques, Jarmakani et al. (22) also found depressed left ventricularejection fraction at rest in patients both before and after repair of tetralogy of Fallot. These studies suggest that the two contracting ventriclesare interdependent with respect to cardiac function and that the presence of left ventriculardysfunction may be relatedto the alteration of right and left ventricular geometry and coordination of the two ventricles during contraction. The controversy regzrdingventricular function in pediatric patients (18-22) probably results from the incomplete adaptation of the young heart to the surgically induced correction. When these patients reach adulthood, the ventricles may reach a new functional level. The improvement

in the right ventricle could be attributed to the corrective operation that removes right ventricular pressure load secondary to outflow tract obstruction. The compromise in left ventricular function could be explained by the fibrosis or

alterationof the interventricularseptum due to the presence of a prosthetic patch (21)and early right ventriculardysfunction, with additional contribution Fromaging. Conelusions. Our follow-upstudy of ticlultswith intracardiac repair of tetralogy of Fallot in childhood indicates that these patients do well in the long term and have an extremely IOWattrition rate. In addition, exercise tolerance remains excellent and ventricular arrhythmias appear very infrequently on serial follow-up examination over a significant period of time. These encouragingoutcomes may be related to natural selection of survivors by this age and t0 a management policy of careful follow-up and aggressive correction of residual hemodynamic abnormalities. However, kfl ventricuku functionmay show signs of milddeteriorationwith time. Althoughthere is no evidenceto date that the decreasedfunction has an impact on subsequent mortalityor morbidity, it warrants further close observation. We conclude that adult patients whose condition is oth-

JACC Vol. 20, No. 2 Ac!gust 3992:295-300

erwise stable 0ver time should continue to IYecarefully followedup after total repalr of tetralogy ofFallot and can be expected to do well. In those with hemody~am~cabnor ities, the condition should be identifiedand corrected wherever possible.

I. Venugopal P, Subramanian S. Intracardiac repair of tetraiogy of Fallot in patients under 5 years of age. Ann Tborac Surg 1974;18:228-40. 2. Pacific0 AD, Bargeron LM, Kirklin JW. Primary total correction of tetralogy of Fallot in children less than 4 years of age. Circulation 1973:48:1085=9l. 3. Garsbn A, Nibill MR. cNamam DG, Cooley DA. Status of adult and adolescenr aRer repair of tetralogy of Fallot. Circulation 1979;59: 1232-40. 4. Gillette: PC, Yeoman MA, Mullins CE, McNamara DG. Sudden death afler reraair of tetralonv of Fallot. Circulation 1977:56%6-71. 5. Quattlebaum TG. V&hese J, Neil1 CA, Dohahbo JS. Sudden death among postoperative patients with tetralogy of Pallot. Circrdction 1976; 54:289-93. 6. James FW, Kaplan S. Chou TC. Unexpected cardiac arrest in patients afarr surgical correction of tetralogy of Fallot. Circulation 1975;52:691-5. 7. Satoh M, Aizawa Y, Murata M. et al. Electrophysiologic study of patients with dysarrhythmias during long-term follow-up after repair of telralogy of Fallot. Br Heart J 1988;29:69-77. 8. Wolff GS, Rowland TW, Ellison RC. Surgically induced right bundle block with left anterior hemit!ock: an ominous sign in postoperative tetralogy of Fallot. Circulation 1972;46:587-94. 9. Marin-Garcia J. Moller JH. Sudden death after opemtive repair of tetralogy of Fallot. Br Heart J 1977:39: 1380-5. IO. World Medical Association. Codes of ethics of World Medical Assocktion: declaration of HLisinki. 3 Clin Res 1966:14:1112-9. I I. Liu PP, Strauss HW. Boucher CA, Block PC,.Okada RD. Comparison of ejection fraction and pulr mary blood volume ratio as markers of left ventricular function changes after coronary angioplasty. J Am Coil Cardiol 1986;8:51 l-6. 12. Walsh EP. Rockenmacher S, Keane JF, Hougen TJ, Lock JE, Castaneda AR. Late results in patients with tetralo8y of Fallot repaired during infancy. Circulation 1988;77:1062-7. 13. Burns RJ. Liu PP, Druck MN, Seawright SJ, Williams WC, McLaughlin PR. Analysis of adults with and without complex ventricular arrhythmias after repair of tetralogy of Fallot. J Am Coil CaKliol 1984;4:226-39. 14. Clayman JA. Ankeny JL. Liebman J. Resultsof completerepair of tetralogy of Fallot in I56 consecutive patients. Am J Surg 1975;130:60)1-7. IS. Kinsley RH. McGoon DC, Lianielson GC, Wallace RB, Mair DD. Pulmonary arterial hypert+=nsion after repair of tetralogy of Fallot. J Thorac Cardiovasc Surg 1974:67: 110-20. 16. Finnegan P. Harder R, Pate1 RG, Ahrams LD, Singh SP. Results of total correction of the tetralogy of Fallot: long-term hemodynamic evaluation at rest and during exercise. Br Heart J 1976;38:934-42. 17. Rocchini AP, Rosenthal A. Freed M, Castenada AR.T?adns AS.Chronic congeslive heart failure after repair of tetralqv of Fallot. Circulation 1977:56:305-IO. 18. Reduto LA,Berger HJ,Johnstone DE,et al. Radionuclide assessment of right and lelt ventricular exercise reserve after total correction of tetralogy of Fallot. Am J Cardiol 1980;4S:lOl3-7. 19. Rosing DR, Borer JS, Kent KM,et al. Long-term hemodynamic and electrocardiographic assessment following operative repair of tetralogy of Fa!lot. Circulation 1978;58(suppl 11%209-17. 20. Bonuw RG, Vitale DF. Bachamch SL, Maron BJ. Green MV.Effects of aging on asynchronous left ventricular regional function and global ventricular filling in normal human subjects. J Am Coil Cardiol 1988;ll: 50-8. 21. Borow KM, Green LH, Castaneda AR, Keane JF. Left ventricular function after repair of tetralogy of Fallot and its relationship to age at surgery. Circulation 1980;61:1150-7. 22. Jarmakani JHM, Graham TP, Canent RV Jr, Jewett PH. Left heart function in children with tetralogy of Fallot before and after palliative and corrective surgery. Circulation 1972;46:478-90.

Serial follow-up of adults with repaired tetralogy of Fallot.

Sudden death has long been considered a major contributor to mortality in pediatric patients with corrected tetralogy of Fallot. However, this may not...
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