LATE VENTRICULAR ARRHYTHMIA IS RARE AFTER EARLY REPAIR OF TETRALOGY OF FALLOT

Objectives. This study was conducted to describe the incidence of vent ricular arrhythmia during prospective long-term follow up in a group o f patients who had repair of tetralogy of Fallot during early childhoo d. Background. Ventricular arrhythmia has been a common finding in pat ients who have undergone repair of tetralogy of Fallot in late childho od or as adults. Whether earlier repair lowers the incidence of late v entricular arrhythmia or late sudden death is unknown. Methods. Twenty -nine asymptomatic patients who underwent repair at age 1.2 to 7.7 yea rs (mean [+/-SD] age 4 +/- 1.4 years) between 1979 and 1984 were studi ed. Twenty-one patients had simple repair (Group A), and eight had com plex or multiple operations (Group B). All had ambulatory electrocardi ographic monitoring preoperatively, postoperatively, at early follow-u p (after 4.2 +/- 1.3 years) and again at late follow-up (after 11.8 +/ - 1.3 years). At late follow-up, 28 subjects also underwent echocardio graphy, and 26 had an exercise test. Results. No patient had significa nt ventricular arrhythmia (greater than or equal to modified Lown grad e 2) before or immediately after repair. There was no significant incr ease in the incidence of arrhythmia at early and late follow-up (14% t o 28%), but at each of these periods the incidence of ventricular arrh ythmia was higher in Group B patients (3 [43%] of 7 vs. 1 [5%] of 22 w ith early repair, p = 0.03; 6 [75%] of 8 vs. 2 [10%] of 21 with late r epair, p = 0.001). No patient had symptoms of arrhythmia, and there we re no sudden deaths. Late ventricular arrhythmia did not correlate wit h estimated right ventricular systolic pressure, outflow tract gradien t or degree of pulmonary incompetence or right ventricular dilation. O n exercise, 5 (19%) of 26 patients had ventricular premature complexes at low levels of exercise that were suppressed at maximal exercise in all patients. Conclusions. Late ventricular arrhythmia is rare in pat ients with successful early correction of tetralogy of Fallot, unless complex or multiple operations are performed.