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The influence of pulmonary insufficiency on ventricular function following repair of tetralogy of Fallot
J
THoRAc CARDIOVASC SURG
85:691-696, 1983
The influence of pulmonary insufficiency on ventricular function following repair of tetralogy of Fallot Evaluation using radionuclide ventriculography Long-standing pulmonary insufficiency after repair of tetralogy of Fallot may adversely affect ventricular function. We evaluated 20 patients at a mean of 9 years after repair by radionuclide ventriculography, 24 hour Holter monitoring, and M-mode echocardiography. The mean age at complete repair was 7.1 ± 2.6 years. Patients were divided into groups as follows: Group I (eight patients), no clinical pulmonary insufficiency; Group II (12 patients), moderate to severe pulmonary insufficiency. Group II was further divided: Group I1a, transannular patch (six patients); Group lib, no transannular patch (six patients). There was no difference between groups for age at operation, duration offollow-up, right ventricular pressure, or right ventricular-pulmonary arterial gradient. No patient had a residual shunt and all were in New York Heart Association Class I. Serious ventricular dysrhythmias occurred in 38% of Group I patients and 50% of Group II (p = NS). The echocardiographic ratio of right to left ventricular end-diastolic dimension was greater in patients with pulmonary insufficiency than in those without pulmonary insufficiency: 0.83 ± 0.17 versus 0.55 ± 0.15, p < 0.01. Right ventricular ejection fraction was 0.39 ± 0.08 in Group I and 0.27 ± 0.07 in Group II, p < 0.01. Left ventricular ejection fraction was 0.64 ± 0.12 in Group I and 0.53 ± 0.07 in Group II, p < 0.02. Radionuclide angiography is a useful means of identifying right ventricular dysfunction following repair of tetralogy of Fallot. The dysfunction appears significantly worse in patients with pulmonary insufficiency.
Edward L. Bove, M.D., Craig J. Byrum, M.D., F. Deaver Thomas, M.D., Rae-Ellen W. Kavey, M.D., Henry M. Sondheimer, M.D., Marie S. Blackman, M.D., and Frederick B. Parker, Jr., M.D., Syracuse, N. Y.
ComPlete repair of tetralogy of Fallot can be accomplished with low operative mortality and excellent long-term symptomatic benefits. The technique used to relieve the right ventricular outflow tract obstruction is an important determinant of early and late cardiac function. Several studies have shown similar functional results between patients treated with a transannular From the Divisions of Cardiac Surgery, Pediatric Cardiology, and Nuclear Medicine, State University of New York, Upstate Medical Center, Syracuse, N. Y. 13210. Received for publication April 7, 1982. Accepted for publication July 22, 1982. Address for reprints: Edward L. Bove, M.D., Department of Surgery, SUNY Upstate Medical Center, 750 E. Adams St., Syracuse, N. Y. 13210.
patch and those left with an intact pulmonary valve."? However, follow-up time is often short'" or the information is based largely on clinical findings.' At least one report suggests that long-standing residual pulmonary insufficiency may not be well tolerated." Repair with a transannular patch resulted in abnormal right ventricular ejection fraction and right ventricular end-diastolic volume in one study," Another investigation showed decreased exercise tolerance in patients with clinical pulmonary insufficiency after complete repair.'? We have studied a group of 20 patients late after repair of tetralogy of Fallot. This report correlates the presence or absence of postrepair pulmonary insufficiency to echocardiographic ventricular dimension, serious ventricular dysrhythmia, and ventricular function as measured by radionuclide ventriculography. 691
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Table I. Clinical and hemodynamic data RV systolic pressure (torr)
PA systolic pressure (torr) 16 24 26 34 22 25 30
Age at operation (yr)
Duration of follow-up (yr)
4 4 6 7 7 8 9 6 6.4 ± 1.8
6 5 11 8 9 II 14 6 8.8 ± 3.1
32 35 39 42 28 45 30 45 37.0 ± 6.7
9 10 II [2 [3 14
7 7 4 8 9 2 6.2 ± 2.6
7 10 3 7 15 5 7.7 ± 4.5
15 16 17 18 19 20
Group lib mean
10 8 7 8 14 6 8.8 ± 2.9
Group II mean
7.5 ± 3.0
Group Group [: No P[
Case No. I 2 3 4 5 6 7 8
Group [ mean Group lIa: PI, TAP
Group lIa mean Group lib: PI, no TAP
RV-PA systolic pressure difference (torr) 16 II 13 8
Serious ventricular dysrhythmia
24.9 ± 7.5
23 12.1 ± 7.5
No No No No No Yes Yes Yes 38%
53 35 55 57 45 21 45.2 ± 2.4
50 32 30 30 30 20 32.0 ± 9.8
3 3 25 27 15 6 13.2 ± 0.9
No No No No Yes No 17%
13 7 II 10 II 10 10.3 ± 2.0
45 43 40 56 50 35 44.8 ± 7.4
23 28 36 45 25 30.7 ± 8.3
22 15 4 29 5 10 14.2 ± 9.9
Yes Yes Yes No Yes Yes 83%
9.0 ± 3.6
45.0 ± 9.7
31.3 ± 8.7
13.7 ± 9.9
50%
22
27
6
20
o
Legend: RV. Right ventricular. PA. Pulmonary arterial. PI, Pulmonary insufficiency. TAP, Transannular patch.
Methods Patient selection. A total of 39 patients underwent complete postoperative evaluation consisting of cardiac catheterization and radionuclide ventriculography after repair of tetralogy of Fallot. The criteria for admission to the study included no residual shunt, resting right ventricular peak systolic pressure of less than 60 torr, resting right ventricular-pulmonary arterial peak systolic gradient of less than 30 torr, and no tricuspid insufficiency. Twenty of these patients met the criteria. Their ages at operation ranged from 2 to 14 years (mean 7.1 ± 2.6 years). Chest roentgenograms were available from all patients within 3 months of the last follow-up date. Cardiothoracic ratio was measured from posteroanterior projections. M-mode echocardiograms were available in 17 patients. The right and left ventricular end-diastolic dimensions were measured in the standard fashionI I. 12 and expressed as a simple ratio. Twenty-four hour Holter monitoring was performed in all patients. Ventricular dysrhythmias were classified according to the
Lown rating criteria." Patients with multiform ventricular premature beats (Grade 3) or successive ventricular premature beats (Grade 4) were categorized as having serious dysrhythmias. Those with isolated uniform ventricular premature beats (Grades 1 and 2, depending on frequency) were not judged to have serious ventricular dysrhythmias. Patient groups. The 20 patients were divided into two groups on the basis of the presence or absence of significant pulmonary insufficiency, a determination made on clinical grounds alone. Group I (n = 8) consisted of patients with no clinical pulmonary insufficiency (seven patients with no diastolic murmur and one patient with a short, trivial diastolic murmur). Group II (n = 12) consisted of the remaining patients who had moderate or severe clinical pulmonary insufficiency (Grade 3/4 to 4/4 diastolic murmur). Group II was further subdivided according to the method of surgical relief of the right ventricular outflow tract obstruction: Group IIa (n = 6) was treated by placement of a transannular patch and excision of pulmonary valve
Volume 85 Number 5 May, 1983
Repair of tetralogy of Fallot
69 3
Table II. Noninvasive studies of ventricular function
Group Group I: No PI
Case No. I
2 3 4 5 6 7 8 Group I mean Group IIa: PI, TAP
9 10 II 12 13 14
Group IIa mean Group lib: PI, no TAP
15 16 17 18 19 20
Roentgenogram: CT ratio 0.52 0.46 0.46 0.50 0.47 0.55 0.48 0.43 0.48 ± 0.04 0.60 0.54 0.62 0.59 0.57 0.57 0.58 ± 0.03
Echocardiogram: RVED/LVED ratio 0.38 0.49 0.50 0.74 0.46 0.73 NA NA
0.55 ± 0.15 1.00 0.74 0.53 1.08 NA
1.00 0.87 ± 0.23
Radionuclide ventriculography RVEF
0.46 0.71 0.77 0.66 0.49 0.72 0.58 0.75 0.64 ± 0.12
0.34 0.29 0.21 0.17 0.25 0.28 0.26 ± 0.06
0.46 0.54 0.58 0.40 0.55 0.52 0.51 ± 0.07 0.56 0.49 0.64 0.61 0.45 0.60 0.56 ± 0.07 0.53 ± 0.07
Group lib mean
0.80 ± 0.08
0.22 0.23 0.36 0.30 0.18 0.35 0.27 ± 0.07
Group II mean
0.53 ± 0.08
0.83 ± 0.17
0.27 ± 0.07
NA
LVEF
0.26 0.36 0.40 0.45 0.48 0.37 0.32 0.51 0.39 ± 0.08
0.42 0.54 0.39 0.42 0.53 0.59 0.48 ± 0.08
0.79 0.80 0.73 0.73 0.93
I
Legend: CT, Cardiothoracic. RVED/LVED, Right ventricular end-diastolic/left ventricular end-diastolic dimension. RVEF, Right ventricular ejection fraction. LVEF, Left ventricular ejection fraction. PI. Pulmonary insufficiency. TAP, Transannular patch. NA, Not available.
tissue; Group lIb (n = 6) had pulmonary valvotomy without a transannular patch. No patient in Group I had a transannular patch. Surgical techniques. All operations were performed at moderate hypothermia with perfusate temperatures between 28° and 32° C. Intermittent aortic crossclamping (15 to 20 minute periods) was used in 19 patients. The most recent patient was subjected to a single period of cardiac arrest induced with crystalloid cardioplegia. Previously placed systemic-pulmonary artery shunts present in 11 patients were interrupted at the beginning of cardiopulmonary bypass. The ventricular septal defects were patched by means of interrupted suture technique. Infundibular muscle resection was carried out to variable degrees and commissurotomy was performed when valvular stenosis was also present. In six patients, a transannular patch was placed and pulmonary valve tissue was excised. Radionuclide ventriculography. Radionuclide ventriculography was performed in all patients from 3 to IS years after operation (mean 9 years) by labeling red blood cells with 99mTc pertechnetate. A Model 420 Ohio
Nuclear mobile scintillation camera with a 10 inch field of view and a high-resolution collimator were used. Ten minute acquisition times were recorded with an on-line mini-computer system (Gamma 11, Digital Equipment Corp., Maynard, Mass.) in the anterior and left lateral views. The degree of obliquity in the lateral projection that best separated the left and right ventricles in these patients was generally the 90 degree left lateral position. In one patient, the anterior view was used because of technical difficulties in separating the right and left ventricles with the left lateral view. No collimator angulation was used. The data obtained from the scintillation camera were recorded in frame mode with the detected R-wave from the electrocardiogram used as a reference into 16 frames spanning the cardiac cycle and subsequently processed into a cine presentation as a guide to the edges of the ventricular cavities. A computer algorithm established a threshold of 15% to adjust the regions of interest to track the ventricular wall motion during systolic contractions. A background region of interest (for subtraction purposes) was established between the ventricular edge at
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Table ID. Serious ventricular dysrhythmia No. of patients Dysrhythmia present Dysrhythmia absent p Value
9 II
Age at operation (yr)
RV systolic pressure (torr)
PA systolic pressure (torr)
8.6 ± 2.5 5.8 ± 2.0 p <0.02
42.0 ± 6.1 41.6 ± 11.7
29.3 ± 7.3 28.3 ± 9.0
NS
NS
CT ratio
Echocardiogram: RVED/LVED ratio
RVEF
LVEF
0.50 ± 0.07 0.52 ± 0.70
0.80 ± 0.08 0.70 ± 0.25
NS
NS
0.31 ± 0.10 0.32 ± 0.10
0.59 ± 0.10 0.56 ± 0.12
NS
NS
For legend see Table II.
end-diastole and end-systole, and ventricular volume curves were obtained from which stroke counts, ejection fraction, and systolic and diastolic time parameters were obtained. Values greater than 0.55 for the left ventricle and 0.45 for the right ventricle are considered normal. '4. 15 Measurements were made without knowledge of the patient's status or the surgical technique. Statistical analysis. Statistical significance at the 95% confidence level was determined by the two-tailed t test for the difference between two means. Chi square and Fisher's exact test were also used as noted. Results The clinical features and catheterization data for the 20 patients are shown in Table I. There was no difference in the age at operation between Groups I and II. The duration of follow-up ranged from 3 years to 15 years (mean 9 years) with no significant difference between groups. Only one patient had had the operation less than 5 years earlier. Systemic-pulmonary artery shunts had been previously performed in six of eight Group I patients (75%) and five of 12 in Group II (42%), P = NS. Cardiac catheterization was performed from I to 6 years after complete repair (mean 2.4 years). Right ventricular and pulmonary arterial pressures were slightly higher in patients with pulmonary regurgitation, but there was no significant difference between the two groups. The peak systolic gradients from the right ventricle to the pulmonary artery were the same in the two groups. Serious ventricular dysrhythmias occurred with similar frequencies in the two groups of patients: three of eight (38%) in Group I and six of 12 (50%) in Group II. The subgroup of patients treated without a transannular patch but left with significant pulmonary insufficiency (Group lIb) had the highest incidence of serious ventricular dysrhythmias: five of six patients, 83%. This difference, however, was not statistically significant when compared to Group IIa (pulmonary insufficiency, transannular patch): one of six patients, 17%; p <0.08.* "Fisher's exact test and chi square analysis.
Cardiothoracic ratios (Table II) in those patients with pulmonary insufficiency in whom a transannular patch had been used (Group IIa) were significantly greater than those in either Group I or Group lIb, p < 0.01. Patients with pulmonary insufficiency (Group II) had a greater right ventricular end-diastolic dimension, reflected as a greater echocardiographic ratio of right to left ventricular size (Table II), than patients without pulmonary insufficiency (0.83 ± 0.17 versus 0.55 ± 0.15, respectively, p < 0.01). However, echocardiographic measurements did not differentiate between those patients within Group II who had been treated with and without a transannular patch (0.87 ± 0.23 versus 0.80 ± 0.08, respectively, p = NS). Comparison of ventricular function between Groups I and II, by means of radionuclide ventriculography, showed better right and left ventricular function in patients without pulmonary insufficiency. Right ventricular ejection fraction was 0.39 ± 0.08 in patients without pulmonary insufficiency (Group I) compared to 0.27 ± 0.07 in patients with pulmonary insufficiency (Group 11), p < om. In those patients with pulmonary insufficiency, the method of relief of right ventricular outflow tract obstruction was not reflected in any difference in right ventricular ejection fraction: 0.26 ± 0.06 in Group I1a versus 0.27 ± 0.07 in Group lIb, p = NS. Left ventricular ejection fraction was also better in those patients without residual pulmonary insufficiency (0.64 ± 0.12) than in those with pulmonary insufficiency (0.53 ± 0.07), p < 0.02. No difference was found in a comparison of left ventricular ejection fraction in patients treated with and without a transannular patch. Discussion The development of dysrhythmias or ventricular dysfunction is a widely recognized late problem following repair of tetralogy of Fallot.' The present study indicates that evaluation of symptoms alone is not sensitive enough to detect patients with impaired ventricular function. Additionally, satisfactory hemodynamics at postoperative cardiac catheterization did not preclude the late development of right ventricular dys-
Volume 85
Repair of tetralogy of Fallot
Number 5 May, 1983
function when significant pulmonary insufficiency was present. The design of this study was to selectively evaluate the problem of pulmonary insufficiency late after repair of tetralogy of Fallot. Therefore, patients with other established reasons for persistent ventricular dysfunction (residual left-to-right shunt, coronary insufficiency, tricuspid regurgitation, or significant residual pulmonary stenosis) were eliminated from consideration. Radionuclide ventriculography is a proved method of evaluating left ventricular function. Although less well established, its use in evaluating right ventricular function appears to be accepted.'>" Because this technique is independent of the geometry of the ventricular chamber, it is particularly appropriate for use with the right ventricle. Our data indicate that patients with clinically moderate to marked pulmonary insufficiency late following repair of tetralogy of Fallot have diminished left and right ventricular function compared to patients with no or minimal regurgitation. Despite this, all patients in our group remained asymptomatic throughout the period of follow-up (mean 9 years) and were in New York Heart Association Class I. Left ventricular ejection fraction was normal in Group I patients (0.64 ± 0.12) and only mildly below normal in Group II (0.53 ± 0.07). Right ventricular ejection fraction was impaired in both groups, although Group I patients (0.39 ± 0.08) were not far below the accepted normal of 0.45. The finding of serious ventricular dysrhythmias late after repair of tetralogy of Fallot did not correlate with noninvasive measures of ventricular function or with the presence of pulmonary insufficiency alone in this group of patients. The only risk factor that predicted an increased incidence of serious ventricular dysrhythmias proved to be older age at operation: 8.6 ± 2.5 years versus 5.8 ± 2.0 years, p < 0.02 (Table III). This finding confirms the results of others.' Additionally, among patients with pulmonary insufficiency, those in whom a transannular patch was not used appear in this small number of patients to have an increased incidence of dysrhythmias (83%) when compared to those patients in whom a transannular patch was used (17%), p < 0.08. The explanation for this is not readily apparent from these data, although one may speculate that adequate relief of obstruction without a transannular patch was achieved at the expense of more myocardial resection and a more generous ventriculotomy. Possibly, increased myocardial fibrosis resulting from the increased muscle resection in addition to volume overload may be the reason for the higher incidence of ventricular dysrhythmias. Only one patient in this study was operated upon with cardioplegia, a technique now routinely utilized. It is
69 5
hoped that this improved method of myocardial protection will help to better preserve myocardial function. Additionally, our technique of repair has evolved to minimize right ventricular resection. The ventricular septal defects are closed through the tricuspid valve and a limited vertical incision is made high in the right ventricular outflow tract. All ventriculotomies are closed with a patch, which is confined below the anulus if the pulmonary valve diameter will allow. 18. 19 In conclusion, the findings of this study indicate that patients with clinically significant pulmonary insufficiency following repair of tetralogy of Fallot have impaired ventricular function late after operation. The importance of radionuclide angiography in the noninvasive assessment of these patients is its ability to uncover and quantify left and right ventricular dysfunction in patients who are asymptomatic. The serial prospective assessment of right ventricular function in patients with pulmonary insufficiency following repair of tetralogy of Fallot may provide guidelines for future pulmonary valve replacement in these patients with regard to preservation of right ventricular function.
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REFERENCES Katz NM, Blackstone EH, Kirklin lW, Pacifico AD, Bargeron LM Jr: Late survival and symptoms after repair of tetralogy of Fallot. Circulation 65:403-410, 1982 Finnegan P, Haider R, Patel RG, Abrams LD, Singh SP: Results of total correction of the tetralogy of Fallot. Br Heart 1 38:934-942, 1976 Arciniegas EA, Farooki ZQ, Hakimi M, Perry BL, Green EW: Early and late results of total correction of tetralogy of Fallot. 1 THORAC CARDIOVASC SURG 80:770-778, 1980 Fuster V, McGoon DC, Kennedy MA, Ritter DG, Kirklin lW: Long-term evaluation (12 to 22 years) of open heart surgery for tetralogy of Fallot. Am 1 Cardiol 46:635-642, 1980 Calder AL, Barratt-Boyes BG, Brandt PWT, Neutze 1M: Postoperative evaluation of patients with tetralogy of Fallot repaired in infancy. 1 THORAC CARDIOVASC SURG 77:704-720, 1979 lones EL, Conti CR, Neill CA, Gott VL, Brawley RK, Haller lA lr: Long-term evaluation of tetralogy patients with pulmonary valvular insufficiency resulting from outflow-patch correction across the pulmonic annulus. Circulation 48:Suppl 3:11-18, 1973 Poirier RA, McGoon DC, Danielson GK, Wallace RB, Ritter DG, Moodie DS, Wiltse CG: Late results after repair of tetralogy of Fallot. 1 THORAC CARDIOVASC SURG 73:900-908, 1977 Kirklin lW, Blackstone EH: Editorial on papers by Naito, Wessel, and their colleagues. 1 THORAC CARDIOVASC SURG 80:594-599, 1980 Graham TP lr, Cordell D, Atwood GF, Boucek Rl lr, Boerth RC, Bender HW, Nelson JH, Vaughn WK: Right
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ventricular volume characteristics before and after palliative and reparative operation in tetralogy of Fallot. Circulation 54:417-423, 1976 Wessel HU, Cunningham WJ, Paul MH, Bastanier CK, Muster AJ, Idriss FS: Exercise performance in tetralogy of Fallot after intracardiac repair. J THoRAc CARDIOVASC SURG 80:582-593, 1980 Sahn DJ, DeMaria A, Kisslo J, Weyman A: Recommendations regarding quantitation in M-mode echocardiography. Results of a survey of echocardiographic measurements. Circulation 58: 1072-1083, 1978 Feigenbaum H: Echocardiographic measurements and normal values, Echocardiography, Philadelphia, 1981, Lea & Febiger, Publishers, p 549 Jellinek MY, Lawn B: Exercise stress testing for exposure of cardiac arrhythmias. Prog Cardiovasc Dis 16:497-522, 1974 Reduto LA, Berger HJ, Johnstone DE, Hellenbrand W, Wackers F, Whittemore R, Cohen LS, Gottschalk A, Zaret BL: Radionuclide assessment of right and left ventricular exercise reserve after total correction of tetralogy of Fallot. Am J Cardiol 45:1013-1018, 1980
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15 Berger HJ, Matthay RA, Lake J, Marshall RC, Gottschalk A, Zaret BL: Assessment of cardiac performance with quantitative radionuclide angiocardiography. Right ventricular ejection fraction with reference to findings in chronic obstructive pulmonary disease. Am J Cardiol 41:897-905, 1978 16 Reduto LA, Berger HJ, Cohen LS, Gottschalk A, Zaret BL: Sequential radionuclide assessment of left and right ventricular performance after acute transmural myocardial infarction. Ann Intern Med 89:441-447, 1978 17 Korr KS, Gandsman EJ, Winkler ML, Shulman RS, Bough EW: Hemodynamic correlates of right ventricular ejection fraction measured with gated radionuclide angiography. Am J CardioI49:71-77, 1982 18 Naito Y, Fujita T, Manabe H, Kawashima Y: The criteria for reconstruction of right ventricular outflow tract in total correction of tetralogy of Fallot. J THORAC CARDIOVASC SURG 80:574-581, 1980 19 Blackstone EH, Kirklin JW, Pacifico AD: Decisionmaking in repair of tetralogy of Fallot based on intraoperative measurements of pulmonary arterial outflow tract. J THORAC CARDIOVASC SURG 77:526-532, 1979
THoRAc CARDIOVASC SURG
85:691-696, 1983
The influence of pulmonary insufficiency on ventricular function following repair of tetralogy of Fallot Evaluation using radionuclide ventriculography Long-standing pulmonary insufficiency after repair of tetralogy of Fallot may adversely affect ventricular function. We evaluated 20 patients at a mean of 9 years after repair by radionuclide ventriculography, 24 hour Holter monitoring, and M-mode echocardiography. The mean age at complete repair was 7.1 ± 2.6 years. Patients were divided into groups as follows: Group I (eight patients), no clinical pulmonary insufficiency; Group II (12 patients), moderate to severe pulmonary insufficiency. Group II was further divided: Group I1a, transannular patch (six patients); Group lib, no transannular patch (six patients). There was no difference between groups for age at operation, duration offollow-up, right ventricular pressure, or right ventricular-pulmonary arterial gradient. No patient had a residual shunt and all were in New York Heart Association Class I. Serious ventricular dysrhythmias occurred in 38% of Group I patients and 50% of Group II (p = NS). The echocardiographic ratio of right to left ventricular end-diastolic dimension was greater in patients with pulmonary insufficiency than in those without pulmonary insufficiency: 0.83 ± 0.17 versus 0.55 ± 0.15, p < 0.01. Right ventricular ejection fraction was 0.39 ± 0.08 in Group I and 0.27 ± 0.07 in Group II, p < 0.01. Left ventricular ejection fraction was 0.64 ± 0.12 in Group I and 0.53 ± 0.07 in Group II, p < 0.02. Radionuclide angiography is a useful means of identifying right ventricular dysfunction following repair of tetralogy of Fallot. The dysfunction appears significantly worse in patients with pulmonary insufficiency.
Edward L. Bove, M.D., Craig J. Byrum, M.D., F. Deaver Thomas, M.D., Rae-Ellen W. Kavey, M.D., Henry M. Sondheimer, M.D., Marie S. Blackman, M.D., and Frederick B. Parker, Jr., M.D., Syracuse, N. Y.
ComPlete repair of tetralogy of Fallot can be accomplished with low operative mortality and excellent long-term symptomatic benefits. The technique used to relieve the right ventricular outflow tract obstruction is an important determinant of early and late cardiac function. Several studies have shown similar functional results between patients treated with a transannular From the Divisions of Cardiac Surgery, Pediatric Cardiology, and Nuclear Medicine, State University of New York, Upstate Medical Center, Syracuse, N. Y. 13210. Received for publication April 7, 1982. Accepted for publication July 22, 1982. Address for reprints: Edward L. Bove, M.D., Department of Surgery, SUNY Upstate Medical Center, 750 E. Adams St., Syracuse, N. Y. 13210.
patch and those left with an intact pulmonary valve."? However, follow-up time is often short'" or the information is based largely on clinical findings.' At least one report suggests that long-standing residual pulmonary insufficiency may not be well tolerated." Repair with a transannular patch resulted in abnormal right ventricular ejection fraction and right ventricular end-diastolic volume in one study," Another investigation showed decreased exercise tolerance in patients with clinical pulmonary insufficiency after complete repair.'? We have studied a group of 20 patients late after repair of tetralogy of Fallot. This report correlates the presence or absence of postrepair pulmonary insufficiency to echocardiographic ventricular dimension, serious ventricular dysrhythmia, and ventricular function as measured by radionuclide ventriculography. 691
The Journal of
692
Rove et al.
Thoracic and Cardiovascular Surgery
Table I. Clinical and hemodynamic data RV systolic pressure (torr)
PA systolic pressure (torr) 16 24 26 34 22 25 30
Age at operation (yr)
Duration of follow-up (yr)
4 4 6 7 7 8 9 6 6.4 ± 1.8
6 5 11 8 9 II 14 6 8.8 ± 3.1
32 35 39 42 28 45 30 45 37.0 ± 6.7
9 10 II [2 [3 14
7 7 4 8 9 2 6.2 ± 2.6
7 10 3 7 15 5 7.7 ± 4.5
15 16 17 18 19 20
Group lib mean
10 8 7 8 14 6 8.8 ± 2.9
Group II mean
7.5 ± 3.0
Group Group [: No P[
Case No. I 2 3 4 5 6 7 8
Group [ mean Group lIa: PI, TAP
Group lIa mean Group lib: PI, no TAP
RV-PA systolic pressure difference (torr) 16 II 13 8
Serious ventricular dysrhythmia
24.9 ± 7.5
23 12.1 ± 7.5
No No No No No Yes Yes Yes 38%
53 35 55 57 45 21 45.2 ± 2.4
50 32 30 30 30 20 32.0 ± 9.8
3 3 25 27 15 6 13.2 ± 0.9
No No No No Yes No 17%
13 7 II 10 II 10 10.3 ± 2.0
45 43 40 56 50 35 44.8 ± 7.4
23 28 36 45 25 30.7 ± 8.3
22 15 4 29 5 10 14.2 ± 9.9
Yes Yes Yes No Yes Yes 83%
9.0 ± 3.6
45.0 ± 9.7
31.3 ± 8.7
13.7 ± 9.9
50%
22
27
6
20
o
Legend: RV. Right ventricular. PA. Pulmonary arterial. PI, Pulmonary insufficiency. TAP, Transannular patch.
Methods Patient selection. A total of 39 patients underwent complete postoperative evaluation consisting of cardiac catheterization and radionuclide ventriculography after repair of tetralogy of Fallot. The criteria for admission to the study included no residual shunt, resting right ventricular peak systolic pressure of less than 60 torr, resting right ventricular-pulmonary arterial peak systolic gradient of less than 30 torr, and no tricuspid insufficiency. Twenty of these patients met the criteria. Their ages at operation ranged from 2 to 14 years (mean 7.1 ± 2.6 years). Chest roentgenograms were available from all patients within 3 months of the last follow-up date. Cardiothoracic ratio was measured from posteroanterior projections. M-mode echocardiograms were available in 17 patients. The right and left ventricular end-diastolic dimensions were measured in the standard fashionI I. 12 and expressed as a simple ratio. Twenty-four hour Holter monitoring was performed in all patients. Ventricular dysrhythmias were classified according to the
Lown rating criteria." Patients with multiform ventricular premature beats (Grade 3) or successive ventricular premature beats (Grade 4) were categorized as having serious dysrhythmias. Those with isolated uniform ventricular premature beats (Grades 1 and 2, depending on frequency) were not judged to have serious ventricular dysrhythmias. Patient groups. The 20 patients were divided into two groups on the basis of the presence or absence of significant pulmonary insufficiency, a determination made on clinical grounds alone. Group I (n = 8) consisted of patients with no clinical pulmonary insufficiency (seven patients with no diastolic murmur and one patient with a short, trivial diastolic murmur). Group II (n = 12) consisted of the remaining patients who had moderate or severe clinical pulmonary insufficiency (Grade 3/4 to 4/4 diastolic murmur). Group II was further subdivided according to the method of surgical relief of the right ventricular outflow tract obstruction: Group IIa (n = 6) was treated by placement of a transannular patch and excision of pulmonary valve
Volume 85 Number 5 May, 1983
Repair of tetralogy of Fallot
69 3
Table II. Noninvasive studies of ventricular function
Group Group I: No PI
Case No. I
2 3 4 5 6 7 8 Group I mean Group IIa: PI, TAP
9 10 II 12 13 14
Group IIa mean Group lib: PI, no TAP
15 16 17 18 19 20
Roentgenogram: CT ratio 0.52 0.46 0.46 0.50 0.47 0.55 0.48 0.43 0.48 ± 0.04 0.60 0.54 0.62 0.59 0.57 0.57 0.58 ± 0.03
Echocardiogram: RVED/LVED ratio 0.38 0.49 0.50 0.74 0.46 0.73 NA NA
0.55 ± 0.15 1.00 0.74 0.53 1.08 NA
1.00 0.87 ± 0.23
Radionuclide ventriculography RVEF
0.46 0.71 0.77 0.66 0.49 0.72 0.58 0.75 0.64 ± 0.12
0.34 0.29 0.21 0.17 0.25 0.28 0.26 ± 0.06
0.46 0.54 0.58 0.40 0.55 0.52 0.51 ± 0.07 0.56 0.49 0.64 0.61 0.45 0.60 0.56 ± 0.07 0.53 ± 0.07
Group lib mean
0.80 ± 0.08
0.22 0.23 0.36 0.30 0.18 0.35 0.27 ± 0.07
Group II mean
0.53 ± 0.08
0.83 ± 0.17
0.27 ± 0.07
NA
LVEF
0.26 0.36 0.40 0.45 0.48 0.37 0.32 0.51 0.39 ± 0.08
0.42 0.54 0.39 0.42 0.53 0.59 0.48 ± 0.08
0.79 0.80 0.73 0.73 0.93
I
Legend: CT, Cardiothoracic. RVED/LVED, Right ventricular end-diastolic/left ventricular end-diastolic dimension. RVEF, Right ventricular ejection fraction. LVEF, Left ventricular ejection fraction. PI. Pulmonary insufficiency. TAP, Transannular patch. NA, Not available.
tissue; Group lIb (n = 6) had pulmonary valvotomy without a transannular patch. No patient in Group I had a transannular patch. Surgical techniques. All operations were performed at moderate hypothermia with perfusate temperatures between 28° and 32° C. Intermittent aortic crossclamping (15 to 20 minute periods) was used in 19 patients. The most recent patient was subjected to a single period of cardiac arrest induced with crystalloid cardioplegia. Previously placed systemic-pulmonary artery shunts present in 11 patients were interrupted at the beginning of cardiopulmonary bypass. The ventricular septal defects were patched by means of interrupted suture technique. Infundibular muscle resection was carried out to variable degrees and commissurotomy was performed when valvular stenosis was also present. In six patients, a transannular patch was placed and pulmonary valve tissue was excised. Radionuclide ventriculography. Radionuclide ventriculography was performed in all patients from 3 to IS years after operation (mean 9 years) by labeling red blood cells with 99mTc pertechnetate. A Model 420 Ohio
Nuclear mobile scintillation camera with a 10 inch field of view and a high-resolution collimator were used. Ten minute acquisition times were recorded with an on-line mini-computer system (Gamma 11, Digital Equipment Corp., Maynard, Mass.) in the anterior and left lateral views. The degree of obliquity in the lateral projection that best separated the left and right ventricles in these patients was generally the 90 degree left lateral position. In one patient, the anterior view was used because of technical difficulties in separating the right and left ventricles with the left lateral view. No collimator angulation was used. The data obtained from the scintillation camera were recorded in frame mode with the detected R-wave from the electrocardiogram used as a reference into 16 frames spanning the cardiac cycle and subsequently processed into a cine presentation as a guide to the edges of the ventricular cavities. A computer algorithm established a threshold of 15% to adjust the regions of interest to track the ventricular wall motion during systolic contractions. A background region of interest (for subtraction purposes) was established between the ventricular edge at
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Table ID. Serious ventricular dysrhythmia No. of patients Dysrhythmia present Dysrhythmia absent p Value
9 II
Age at operation (yr)
RV systolic pressure (torr)
PA systolic pressure (torr)
8.6 ± 2.5 5.8 ± 2.0 p <0.02
42.0 ± 6.1 41.6 ± 11.7
29.3 ± 7.3 28.3 ± 9.0
NS
NS
CT ratio
Echocardiogram: RVED/LVED ratio
RVEF
LVEF
0.50 ± 0.07 0.52 ± 0.70
0.80 ± 0.08 0.70 ± 0.25
NS
NS
0.31 ± 0.10 0.32 ± 0.10
0.59 ± 0.10 0.56 ± 0.12
NS
NS
For legend see Table II.
end-diastole and end-systole, and ventricular volume curves were obtained from which stroke counts, ejection fraction, and systolic and diastolic time parameters were obtained. Values greater than 0.55 for the left ventricle and 0.45 for the right ventricle are considered normal. '4. 15 Measurements were made without knowledge of the patient's status or the surgical technique. Statistical analysis. Statistical significance at the 95% confidence level was determined by the two-tailed t test for the difference between two means. Chi square and Fisher's exact test were also used as noted. Results The clinical features and catheterization data for the 20 patients are shown in Table I. There was no difference in the age at operation between Groups I and II. The duration of follow-up ranged from 3 years to 15 years (mean 9 years) with no significant difference between groups. Only one patient had had the operation less than 5 years earlier. Systemic-pulmonary artery shunts had been previously performed in six of eight Group I patients (75%) and five of 12 in Group II (42%), P = NS. Cardiac catheterization was performed from I to 6 years after complete repair (mean 2.4 years). Right ventricular and pulmonary arterial pressures were slightly higher in patients with pulmonary regurgitation, but there was no significant difference between the two groups. The peak systolic gradients from the right ventricle to the pulmonary artery were the same in the two groups. Serious ventricular dysrhythmias occurred with similar frequencies in the two groups of patients: three of eight (38%) in Group I and six of 12 (50%) in Group II. The subgroup of patients treated without a transannular patch but left with significant pulmonary insufficiency (Group lIb) had the highest incidence of serious ventricular dysrhythmias: five of six patients, 83%. This difference, however, was not statistically significant when compared to Group IIa (pulmonary insufficiency, transannular patch): one of six patients, 17%; p <0.08.* "Fisher's exact test and chi square analysis.
Cardiothoracic ratios (Table II) in those patients with pulmonary insufficiency in whom a transannular patch had been used (Group IIa) were significantly greater than those in either Group I or Group lIb, p < 0.01. Patients with pulmonary insufficiency (Group II) had a greater right ventricular end-diastolic dimension, reflected as a greater echocardiographic ratio of right to left ventricular size (Table II), than patients without pulmonary insufficiency (0.83 ± 0.17 versus 0.55 ± 0.15, respectively, p < 0.01). However, echocardiographic measurements did not differentiate between those patients within Group II who had been treated with and without a transannular patch (0.87 ± 0.23 versus 0.80 ± 0.08, respectively, p = NS). Comparison of ventricular function between Groups I and II, by means of radionuclide ventriculography, showed better right and left ventricular function in patients without pulmonary insufficiency. Right ventricular ejection fraction was 0.39 ± 0.08 in patients without pulmonary insufficiency (Group I) compared to 0.27 ± 0.07 in patients with pulmonary insufficiency (Group 11), p < om. In those patients with pulmonary insufficiency, the method of relief of right ventricular outflow tract obstruction was not reflected in any difference in right ventricular ejection fraction: 0.26 ± 0.06 in Group I1a versus 0.27 ± 0.07 in Group lIb, p = NS. Left ventricular ejection fraction was also better in those patients without residual pulmonary insufficiency (0.64 ± 0.12) than in those with pulmonary insufficiency (0.53 ± 0.07), p < 0.02. No difference was found in a comparison of left ventricular ejection fraction in patients treated with and without a transannular patch. Discussion The development of dysrhythmias or ventricular dysfunction is a widely recognized late problem following repair of tetralogy of Fallot.' The present study indicates that evaluation of symptoms alone is not sensitive enough to detect patients with impaired ventricular function. Additionally, satisfactory hemodynamics at postoperative cardiac catheterization did not preclude the late development of right ventricular dys-
Volume 85
Repair of tetralogy of Fallot
Number 5 May, 1983
function when significant pulmonary insufficiency was present. The design of this study was to selectively evaluate the problem of pulmonary insufficiency late after repair of tetralogy of Fallot. Therefore, patients with other established reasons for persistent ventricular dysfunction (residual left-to-right shunt, coronary insufficiency, tricuspid regurgitation, or significant residual pulmonary stenosis) were eliminated from consideration. Radionuclide ventriculography is a proved method of evaluating left ventricular function. Although less well established, its use in evaluating right ventricular function appears to be accepted.'>" Because this technique is independent of the geometry of the ventricular chamber, it is particularly appropriate for use with the right ventricle. Our data indicate that patients with clinically moderate to marked pulmonary insufficiency late following repair of tetralogy of Fallot have diminished left and right ventricular function compared to patients with no or minimal regurgitation. Despite this, all patients in our group remained asymptomatic throughout the period of follow-up (mean 9 years) and were in New York Heart Association Class I. Left ventricular ejection fraction was normal in Group I patients (0.64 ± 0.12) and only mildly below normal in Group II (0.53 ± 0.07). Right ventricular ejection fraction was impaired in both groups, although Group I patients (0.39 ± 0.08) were not far below the accepted normal of 0.45. The finding of serious ventricular dysrhythmias late after repair of tetralogy of Fallot did not correlate with noninvasive measures of ventricular function or with the presence of pulmonary insufficiency alone in this group of patients. The only risk factor that predicted an increased incidence of serious ventricular dysrhythmias proved to be older age at operation: 8.6 ± 2.5 years versus 5.8 ± 2.0 years, p < 0.02 (Table III). This finding confirms the results of others.' Additionally, among patients with pulmonary insufficiency, those in whom a transannular patch was not used appear in this small number of patients to have an increased incidence of dysrhythmias (83%) when compared to those patients in whom a transannular patch was used (17%), p < 0.08. The explanation for this is not readily apparent from these data, although one may speculate that adequate relief of obstruction without a transannular patch was achieved at the expense of more myocardial resection and a more generous ventriculotomy. Possibly, increased myocardial fibrosis resulting from the increased muscle resection in addition to volume overload may be the reason for the higher incidence of ventricular dysrhythmias. Only one patient in this study was operated upon with cardioplegia, a technique now routinely utilized. It is
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hoped that this improved method of myocardial protection will help to better preserve myocardial function. Additionally, our technique of repair has evolved to minimize right ventricular resection. The ventricular septal defects are closed through the tricuspid valve and a limited vertical incision is made high in the right ventricular outflow tract. All ventriculotomies are closed with a patch, which is confined below the anulus if the pulmonary valve diameter will allow. 18. 19 In conclusion, the findings of this study indicate that patients with clinically significant pulmonary insufficiency following repair of tetralogy of Fallot have impaired ventricular function late after operation. The importance of radionuclide angiography in the noninvasive assessment of these patients is its ability to uncover and quantify left and right ventricular dysfunction in patients who are asymptomatic. The serial prospective assessment of right ventricular function in patients with pulmonary insufficiency following repair of tetralogy of Fallot may provide guidelines for future pulmonary valve replacement in these patients with regard to preservation of right ventricular function.
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REFERENCES Katz NM, Blackstone EH, Kirklin lW, Pacifico AD, Bargeron LM Jr: Late survival and symptoms after repair of tetralogy of Fallot. Circulation 65:403-410, 1982 Finnegan P, Haider R, Patel RG, Abrams LD, Singh SP: Results of total correction of the tetralogy of Fallot. Br Heart 1 38:934-942, 1976 Arciniegas EA, Farooki ZQ, Hakimi M, Perry BL, Green EW: Early and late results of total correction of tetralogy of Fallot. 1 THORAC CARDIOVASC SURG 80:770-778, 1980 Fuster V, McGoon DC, Kennedy MA, Ritter DG, Kirklin lW: Long-term evaluation (12 to 22 years) of open heart surgery for tetralogy of Fallot. Am 1 Cardiol 46:635-642, 1980 Calder AL, Barratt-Boyes BG, Brandt PWT, Neutze 1M: Postoperative evaluation of patients with tetralogy of Fallot repaired in infancy. 1 THORAC CARDIOVASC SURG 77:704-720, 1979 lones EL, Conti CR, Neill CA, Gott VL, Brawley RK, Haller lA lr: Long-term evaluation of tetralogy patients with pulmonary valvular insufficiency resulting from outflow-patch correction across the pulmonic annulus. Circulation 48:Suppl 3:11-18, 1973 Poirier RA, McGoon DC, Danielson GK, Wallace RB, Ritter DG, Moodie DS, Wiltse CG: Late results after repair of tetralogy of Fallot. 1 THORAC CARDIOVASC SURG 73:900-908, 1977 Kirklin lW, Blackstone EH: Editorial on papers by Naito, Wessel, and their colleagues. 1 THORAC CARDIOVASC SURG 80:594-599, 1980 Graham TP lr, Cordell D, Atwood GF, Boucek Rl lr, Boerth RC, Bender HW, Nelson JH, Vaughn WK: Right
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ventricular volume characteristics before and after palliative and reparative operation in tetralogy of Fallot. Circulation 54:417-423, 1976 Wessel HU, Cunningham WJ, Paul MH, Bastanier CK, Muster AJ, Idriss FS: Exercise performance in tetralogy of Fallot after intracardiac repair. J THoRAc CARDIOVASC SURG 80:582-593, 1980 Sahn DJ, DeMaria A, Kisslo J, Weyman A: Recommendations regarding quantitation in M-mode echocardiography. Results of a survey of echocardiographic measurements. Circulation 58: 1072-1083, 1978 Feigenbaum H: Echocardiographic measurements and normal values, Echocardiography, Philadelphia, 1981, Lea & Febiger, Publishers, p 549 Jellinek MY, Lawn B: Exercise stress testing for exposure of cardiac arrhythmias. Prog Cardiovasc Dis 16:497-522, 1974 Reduto LA, Berger HJ, Johnstone DE, Hellenbrand W, Wackers F, Whittemore R, Cohen LS, Gottschalk A, Zaret BL: Radionuclide assessment of right and left ventricular exercise reserve after total correction of tetralogy of Fallot. Am J Cardiol 45:1013-1018, 1980
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15 Berger HJ, Matthay RA, Lake J, Marshall RC, Gottschalk A, Zaret BL: Assessment of cardiac performance with quantitative radionuclide angiocardiography. Right ventricular ejection fraction with reference to findings in chronic obstructive pulmonary disease. Am J Cardiol 41:897-905, 1978 16 Reduto LA, Berger HJ, Cohen LS, Gottschalk A, Zaret BL: Sequential radionuclide assessment of left and right ventricular performance after acute transmural myocardial infarction. Ann Intern Med 89:441-447, 1978 17 Korr KS, Gandsman EJ, Winkler ML, Shulman RS, Bough EW: Hemodynamic correlates of right ventricular ejection fraction measured with gated radionuclide angiography. Am J CardioI49:71-77, 1982 18 Naito Y, Fujita T, Manabe H, Kawashima Y: The criteria for reconstruction of right ventricular outflow tract in total correction of tetralogy of Fallot. J THORAC CARDIOVASC SURG 80:574-581, 1980 19 Blackstone EH, Kirklin JW, Pacifico AD: Decisionmaking in repair of tetralogy of Fallot based on intraoperative measurements of pulmonary arterial outflow tract. J THORAC CARDIOVASC SURG 77:526-532, 1979