Sudden cardiac death and late arrhythmias after the Fontan operation

We sought to examine the incidence and predictors of arrhythmias and sudden cardiac death (SCD) after Fontan operation.

Arrhythmias and SCD have been reported following operations for congenital heart disease, but the incidence and risk factors have not been well defined in patients after a Fontan operation.

We reviewed records of all patients who had a Fontan operation from 1973 to 2012 (n = 1052) at our institution. A questionnaire was mailed to patients who were not known to be deceased at the initiation of the study. Late arrhythmias were classified as bradyarrhythmias or tachyarrhythmias requiring treatment >30 days after operation.

We included 996/1052 (95%) patients with no arrhythmia diagnosis prior to Fontan. Overall 10-, 20-, and 30-year freedom from arrhythmias was 71%, 42%, and 24%, respectively. Of 864 patients who survived >30 days after Fontan, 304 (35%) had atrial flutter, 161 (19%) had atrial fibrillation, 108 (13%) had atrial tachycardia, 37 (4%) had reentrant supraventricular tachycardia, 40 (5%) had ventricular tachycardia, and 113 (13%) had sinus node dysfunction. Predictors of late arrhythmias included an atriopulmonary Fontan, age at operation (>16 years) or atrial arrhythmias postoperatively. During follow-up, 52/1052 (5%) patients had SCD, with 51 having documentation available; 8 patients died suddenly within 30 days and the remaining 43 had an average time to SCD of 6.9 ± 6.7 years (median was 3.8 years). Arrhythmias were documented in 28/43 (65%) patients prior to SCD. Predictors of SCD included atrioventricular valve replacement and post-bypass Fontan pressures >20 mm Hg; preoperative sinus rhythm was protective.

Arrhythmias and SCD are significant concerns among Fontan patients and specific risk factors may warrant closer follow-up and earlier consideration for therapy.