HIGH-ENERGY TRANSCATHETER CARDIOVERSION FOR CHRONIC, POORLY TOLERATEDATRIAL-FIBRILLATION

Between August 1991 and May 1993, 14 patients affected by chronic, poo rly tolerated atrial fibrillation (AF) were submitted to high energy t ranscatheter cardioversion. Mean duration of AF was 27.4 +/- 45.1 mont hs. In nine patients (56%), AF lasted for > 1 year. All patients had u nderlying heart disease, with a mean LVEF of 45.2% +/- 11.8% and a NYH A Class greater than or equal to II. Previously, a mean of 2.9 +/- 1.3 patients failed external electrical cardioversion, with and without a ntiarrhythmics, have been attempted. Transcatheter conversion was perf ormed by pulling the His-bundle catheter back in the right atrial cavi ty until no His bundle activity was recorded on distal poles, and then delivering the shock between a proximal electrode (cathode) and a bac k plate (anode). In all patients, transcatheter conversion restored si nus rhythm. Transient complete atrioventricular (AV) block was observe d in four patients (28%), and treated by prophylactic temporary pacing . At 1 year seven patients (50%) were still in sinus rhythm. In this s eries, only younger age could be related to AF recurrence (46.1 +/- 10 .8 vs 63.4 +/- 6.8 years, P less than or equal to 0.004), even if prop hylaxis with amiodarone showed a positive trend versus sinus rhythm ma intenance (71% vs 14%, P = NS). in conclusion, high energy transcathet er cardioversion is a safe and effective method of restoring sinus rhy thm in patients with chronic, poorly tolerated AF. In these patients, high energy transcatheter cardioversion could be considered as an alte rnative to AV node ablation techniques, avoiding pacemaker implant and embolic risk. Larger studies are needed to determine better patient s election and delineate drug strategy after the procedure.