PERMANENT PACING IN EBSTEINS-ANOMALY

Patients with Ebstein's anomaly present unique challenges to permanent pacing due to anatomical variations and tricuspid valve replacement. We retrospectively reviewed our experience with permanent pacing in pa tients with Ebstein's anomaly between 1976 and 1993. We identified 401 patients with Ebstein's anomaly, of whom 15 (3.7%) required permanent pacing (1 of the 15 was implanted elsewhere). Of the 15, there were 8 females and 7 males (mean age 32 years [range 7-74]); the indications for pacing were AV block in 11 and sinus node dysfunction in 4. Eight patients were programmed with VVI and seven with DDD. All WI patients were paced epicardially. Two patients with DDD pacemakers had transve nous atrial and ventricular leads, 4 DDD patients had transvenous atri al leads and epicardial ventricular leads, and 1 patient had both epic ardial and transvenous systems. Associated surgical procedures include d tricuspid valve replacement in 14 of 15, atrial septal defect repair in 10 of 15, atrioplasty in 7 of 15, prior tricuspid annuloplasty in 4 of 15, pulmonary vein dilation in 1 of 15, and conduction system abl ation in 2 of 15. Patients had a mean follow-up of 35 months (range 1- 168 months). Complications requiring operative intervention occurred i n four patients. One patient had displacement of a transvenous ventric ular lead. A second patient had an epicardial lead failure. A third pa tient had a nonfunctioning atrial lead that displaced across the tricu spid valve, causing severe tricuspid regurgitation. The fourth patient had multiple epicardial and endocardial leads exit block with seconda ry diaphragmatic stimulation. Permanent pacemakers were required in 3. 7% of patients with Ebstein's anomaly, with the indication being intri nsic conduction disease in the majority of patients. Ninety-three perc ent of patients required tricuspid valve replacement, suggesting more severe manifestation of Ebstein's anomaly. Twenty-seven percent had co mplications requiring surgical intervention. Thus, permanent pacing in patients with Ebstein's anomaly can be challenging and should be appr oached by an experienced physician.