Outcomes of late atrial tachyarrhythmias in adults after the Fontan operation

OBJECTIVES The purpose of this study was to compare the clinical and echoca rdiographic features of adults who developed atrial tachyarrhythmias (ATs) late alter a Fontan procedure with those who have remained free of arrhythm ias. BACKGROUND Atrial tachyarrhythmias are a frequent complication of the Fonta n operation. However, the outcomes in adult patients with AT who have had t he Fontan operation have not been well. defined. METHODS We reviewed the outcomes of 94 consecutive patients who underwent t he Fontan operation between 1977 and 1994 and were followed as adults at th e University of Toronto Congenital Cardiac Centre for Adults. Sixty patient s had an atriopulmonary connection, 21 patients had an atrioventricular con nection, and 13 patients received a lateral tunnel connection. RESULTS Thirty-nine patients (41%) had sustained AT (atrial fibrillation, a trial flutter or supraventricular tachycardia) after their Fontan procedure . Compared with patients who did not develop AT, those who did were more li kely to develop heart failure (46% vs. 13%, p = 0.003) and right atrial thr ombus (31% vs. 4%, p = 0.006), exhibit left atrial enlargement (mean [+/-SD ] diameter: 44 +/- 10 vs. 37 +/- 9 mm, p = 0.002), exhibit right atrial enl argement (mean [+/-SD] volume: 139 +/- 149 vs. 76 +/- 54 mi, p = 0.040) and have moderate-to-severe systemic valve regurgitation (31% vs. 7%, p = 0.01 0). The mean survival time was not significantly different between the arrh ythmia group and the arrhythmia-free group (21.2 +/- 1.3 and 18.0 +/- 0.7 y ears, respectively; p = 0.900). CONCLUSIONS Systemic atrioventricular valvular regurgitation and biatrial e nlargement are commonly observed in patients who develop AT after the Fonta n procedure. These patients are more likely to develop right atrial thrombu s and heart failure. (C) 2001 by the American College of Cardiology.