Effects of transcatheter cardioversion on chronic lone atrial fibrillation.

The effectiveness and safety of internal transcatheter cardioversion on chronic lone atrial fibrillation were examined in ten patients resistant to external electrical (400 joules) and pharmacological cardioversion. Transcatheter cardioversion was performed by pulling back the atrioventricular junction catheter just inferior to the site of the His-bundle recording and delivering the shock between a proximal electrode (cathode) and backplate (anode). Transcatheter cardioversion restored sinus rhythm in all of the ten patients. The only complication observed was transient atrioventricular block after the shock and this was treated by temporary pacing. However, atrial fibrillation recurred in five patients at 30, 27, 52, 1, and 6 days, respectively. A second attempt at transcatheter cardioversion was performed in those patients an was successful in three patients. During a follow-up period ranging from 12 to 22 months, eight patients continued in sinus rhythm. Thus, transcatheter cardioversion is considered effective and safe in selected patients with chronic lone atrial fibrillation in whom external cardioversion was unsuccessful.