Late ventricular arrhythmia is rare after early repair of tetralogy of Fallot.

This study was conducted to describe the incidence of ventricular arrhythmia during prospective long-term follow-up in a group of patients who had repair of tetralogy of Fallot during early childhood. Ventricular arrhythmia has been a common finding in patients who have undergone repair of tetralogy of Fallot in late childhood or as adults. Whether earlier repair lowers the incidence of late ventricular arrhythmia or late sudden death is unknown. Twenty-nine asymptomatic patients who underwent repair at age 1.2 to 7.7 years (mean [+/- SD] age 4 +/- 1.4 years) between 1979 and 1984 were studied. Twenty-one patients had simple repair (Group A), and eight had complex or multiple operations (Group B). All had ambulatory electrocardiographic monitoring preoperatively, postoperatively, at early follow-up (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 echocardiography, and 26 had an exercise test. No patient had significant ventricular arrhythmia (> or = modified Lown grade 2) before or immediately after repair. There was no significant increase in the incidence of arrhythmia at early and late follow-up (14% to 28%), but at each of these periods the incidence of ventricular arrhythmia was higher in Group B patients (3 [43%] of 7 vs. 1 [5%] of 22 with early repair, p = 0.03; 6 [75%] of 8 vs. 2 [10%] of 21 with late repair, p = 0.001). No patient had symptoms of arrhythmia, and there were no sudden deaths. Late ventricular arrhythmia did not correlate with estimated right ventricular systolic pressure, outflow tract gradient or degree of pulmonary incompetence or right ventricular dilation. On exercise, 5 (19%) of 26 patients had ventricular premature complexes at low levels of exercise that were suppressed at maximal exercise in all patients. Late ventricular arrhythmia is rare in patients with successful early correction of tetralogy of Fallot, unless complex or multiple operations are performed.