LONG-TERM PACEMAKER DEPENDENCY AFTER RADIOFREQUENCY ABLATION OF THE ATRIOVENTRICULAR JUNCTION

This prospective study was conducted to determine the percentage of pa tients with long-term pacemaker dependency after successful radiofrequ ency ablation of the atrioventricular junction. Abrupt inhibition of t he pacemaker was performed 13.5 +/- 8.1 months after ablation in 59 pa tients. A greater than or equal to 5-second asystole was considered to indicate pacemaker dependency. Pacemaker dependency was present in 18 patients. Absence of escape rhythm immediately after ablation was str ongly associated with a higher incidence of longterm pacemaker depende ncy. The following variables were not associated with pacemaker depend ency: age, presence of cardiac disease, presence of preablation bundle branch block, number of radiofrequency applications, a bilateral appr oach for ablation, and continuation of antiarrhythmic therapy after ab lation. We concluded that (1) long-term pacemaker dependency is presen t in 30.5% of the patients after successful atrioventricular junction radiofrequency ablation and (2) absence of escape rhythm immediately a fter ablation predicts long-term pacemaker dependency.