The Preoperative and Postoperative Findings in 627 Patients with Tetralogy of Fallot*

Summary

The preoperative and postoperative findings in 627 patients operated for correction of tetralogy of Fallot (TOF) in the period 1960 to 1984 were analyzed in order to evaluate the clinical and hemodynamic late results. The average age was 7.2 years (range 9 months to 30 years). The patients were divided into 4 groups in order to determine the long-term prognosis in relation to the severity of the underlying anatomy; group I = without outflow tract patch; group II = with a patch up to the valve base; group III = with a transannular patch (TAP); group IV = TAP or valved conduit in patients with pulmonary atresia. Preceding shunt operations had been performed in 350 patients (55.8%); a primary correction was carried out in 277 cases (44.1 %). Hospital mortality for all patients operated from 1960 to 1984 was 14.0%, late mortality, by contrast, was only 1.1 %. In the last 4 years (1980 to 1983), the overall mortality considerably decreased to 3.4% (n = 29) for patients without TAP and to 8.0% for all operated patients including those with pulmonary atresia (n = 50). A comparíson of the actuarial survival curves, moreover, demonstrates that the prognostic survival rate is unequivocally dependent on the severity of the anatomy of a TOF.

The hemodynamic results obtained from 271 recatheterized patients from all 4 groups were designated excellent in 106 patients (39.1 %), good in 100 (39.9%) and poor in 65 (23.9%). Proximal residual gradients across the right ventricular outflow tract (RVOT) were found in 30.2% of the corrected patients, and distal gradients in 24.3%. Fifty-two patients out of the 627 (8.2%) had to be reoperated for residual VSD, RVOT aneurysm, valvular pulmonary stenosis or peripheral stenosis. Intracardial electrophysiological tests carried out in 166 patients postoperatively showed an antegrade effective refractory period of the AV-node lasting over 400 ms in 47 patients (28.3%), as well as additional ventricular action potentials in 117 patients (70.4%), which could be correlated to extrasystoles or ventricular tachycardia in 37.9% of the cases. Additional AV-pathways were disclosed in 3 patients.

Cardiac recatheterization with electrophysiological studies are necessary following correction of TOF because clinical findings alone do not allow for the evaluation of hemodynamic late results. Even in cases with good hemodynamic results, cardiac rhythm analysis can uncover specific findings which could explain a possible later appearance of cardiac dysrhythmias. We shall continue to favor palliation for the widening of the pulmonary vascular bed in those cases with unfavorable anatomy of TOF under 2 years of age.

Key words

Tetralogy of Fallot - Preoperative and postoperative studies