Low energy internal atrial cardioversion in atrial fibrillation lasting more than a year

The aim of this study was to evaluate the efficacy of low energy internal a trial cardioversion in restoring sin us rhythm (SR) in patients with chroni c atrial fibrillation (AF) persisting > 1 year. Fifteen patients with chron ic AF lasting > 1 year (from 13-48 months, mean 24 +/- 13 months) were stud ied. R wave synchronized 3/3 ms biphasic shocks were delivered between righ t atrial and coronary sinus (left pulmonary artery in five patients) electr odes. Sedatives or anesthetics were administered only at the patient's requ est. Results: Stable SR was restored in 14 (93%) of 15 patients after shock s with a mean leading edge voltage of 377 +/- 77 V (range 260-500) and a me an delivered energy of 7.3 +/- 3.4 J (range 2.6-12.9). The procedure was pe rformed without anesthesia in 6 (40%) patients. All successfully cardiovert ed patients were treated with flecainide, sotalol, or amiodarone. During a follow up of 7.7 +/- 7.9 months (range 1-24) AF recurred in five (36%) pati ents. Three of five AF recurrences occurred within 3 days after conversion to SR. Conclusion: internal low energy atrial cardioversion is highly effec tive in restoring SR even in patients with AF lasting > 1 year. The long-te rm results from the standpoint of freedom from AF recurrences, are satisfac tory, although additional antiarrhythmic treatment is required, particularl y in the first days after conversion.