Catheter ablation of the atrioventricular junction: a report of the percutaneous mapping and ablation registry.

An international registry was formed to collate data for patients undergoing attempted catheter ablation of the atrioventricular (AV) junction and insertion of a permanent pacemaker. Over the past 2 years, data was submitted for 127 patients who were followed for a mean of 9.9 +/- 8.2 months. The most common arrhythmia treated was chronic or paroxysmal atrial fibrillation or flutter (78 patients, 61%); the remainder had supraventricular tachycardia due to AV node reentry, ectopic atrial tachycardia, or incorporated an accessory pathway. A single shock of 150 to 400 J was effective in producing chronic third-degree AV block in 45 patients while two or more shocks were used in an additional 45 patients. There was no significant difference in the total cumulative energy used in successful and unsuccessful procedures. Immediate complications related to the shock included ventricular fibrillation (one patient), pericardial tamponade (one patient), and transient hypotension (one patient). No chronic sequelae occurred as a result of these complications. Late complications (1 day to 1 month) included ventricular tachycardia (three patients), sepsis involving the pacemaker pocket (two patients), staphylococcal sepsis from temporary pacing catheter (one patient), thrombophlebitis (one patient), thrombosis of the left subclavian vein (one patient), and hemothorax (one patient). Follow-up evaluation revealed chronic third degree AV block in 90 (71%) and AV conduction resumed but no drugs were required for arrhythmia control in eight (6.5%) and arrhythmia control was achieved with previously ineffective drugs in 16 (13%). Thirteen patients (10%) had no improvement and five of these patients underwent cardiac electrosurgery for direct His bundle ablation.(ABSTRACT TRUNCATED AT 250 WORDS)