Effect of Ebstein's anomaly on short- and long-term outcome of surgically treated patients with Wolff-Parkinson-White syndrome.

BACKGROUND Ebstein's anomaly is the most commonly occurring congenital abnormality associated with the Wolff-Parkinson-White (WPW) syndrome. However, the effects of Ebstein's anomaly on the risks and benefits of surgical ablation of accessory pathways in patients with WPW syndrome are unknown. METHODS AND RESULTS This study compared the long-term outcome of 38 WPW patients with Ebstein's anomaly undergoing accessory pathway ablation to a reference population of 384 similarly treated patients without the anomaly. Ebstein's anomaly was mild in 21 patients (55%) and moderate-to-severe in 17 patients (45%). Sixteen patients (42%) required tricuspid valve surgery, and 23 (61%) had an atrial septal defect or patent foramen ovale repaired. Baseline clinical characteristics and preoperative clinical arrhythmias were similar in both groups. Ten-year survival was 92.4% and 91.2% for patients with and without Ebstein's anomaly, respectively (p = NS). During a mean follow-up of 6.2 +/- 3.8 and 5.3 +/- 3.6 years, 82% of patients with and 90% without Ebstein's anomaly had either clinically insignificant or no arrhythmias, and 18% versus 10% reported symptoms suggesting arrhythmias lasting longer than 1 minute, respectively. Atrial fibrillation was reduced postoperatively to 9% (p less than 0.001) in patients with and to 4% (p less than 0.001) in those without the anomaly. Fewer hospitalizations were reported postoperatively by 90% versus 96% of patients with and without Ebstein's anomaly; 9.4% versus 6.0% of patients were disabled at follow-up, respectively (p = NS). CONCLUSIONS Patients with Ebstein's anomaly are improved significantly after accessory pathway ablation. The presence of this anomaly should not preclude accessory pathway ablation in these patients.