[Long-term evaluation after correction of tetralogy of Fallot]

The long-term survivors of the patients who underwent corrective surgery for tetralogy of Fallot between 1956 and 1988 were analyzed with respect to symptoms, late death, reoperation, and ventricular arrhythmias. For analysis, these 380 patients were separated into three periods, April 1956-December 1968 (Period 1), January 1968-May 1978 (Period 2), and June 1978-December 1988 (Period 3). In Period 3, the intracardiac procedures were performed with or without minimal right ventriculotomy. There were 24 late deaths (6.3%), and 10 of them were sudden. Nine patients (2.4%) required reoperation. Actuarial reoperation free survival rate was 93.8% at 10 years, 90.0% at 20 years, and 85.3% at 30 years. There were no differences in the actuarial curve between 3 periods though there was no late death in Period 3. NYHA functional class was I in 229 (80%) out of all 287 patients whose symptoms were clear to follow up, II in 50 (17), and III in 8 (3%). There was no patient in NYHA class IV. The incidence of NYHA class II and III was significantly higher in Period 1 (23%) and 2 (28%) than Period 3 (7%) (p less than 0.01, p less than 0.01). Ventricular arrhythmias were evaluated in 155 patients with ambulatory electrocardiography. Significant ventricular arrhythmias of Lown's grade 2 to 4 were detected in 52 patients (34%). The incidence of significant ventricular arrhythmias of Lown's grade 2 to 4 was significantly higher in Period 1 (50%) and 2 (53%) than Period 3 (15%) (p less than 0.01, p less than 0.01). Thus symptoms and ventricular arrhythmias increased when the follow-up interval exceeded 10 years or in patients with large ventriculotomy.