Duty-cycled unipolar/bipolar versus conventional radiofrequency ablation in paroxysmal and persistent atrial fibrillation

Background: Duty-cycled (DC) radiofrequency ablation (RFA) for atrial fibrillation (AF) has been introduced, however, data on large patient series and comparison to conventional RFA are scarce. Methods: Between 2006 and 2008 DC RFA was performed in 209 consecutive patients (143 (68%) paroxysmal and 66 (32%) persistent AF). As controls served 211 patients, 155 (73%) with paroxysmal and 56 (27%) with persistent AF (p=0.3). In DC RFA, the pulmonary veins (PV) were isolated followed by ablation at the septum and left atrium, if AF persisted. Conventional PV isolation was followed by anatomical lines at the roof and mitral isthmus. Results: Freedom of paroxysmal AF was demonstrated after 1.08 DC RFA procedures per patient in 82% and after 1.19 conventional procedures in 87% after 8.5 +/- 6.5 months (ns). In persistent AF, success rates were 79% after 1.35 DC RFA procedures and 80% after 1.34 conventional procedures after 11.5 +/- 8.5 months (ns). The subgroup analysis of 119 patients with follow-up >= 12 months (17.5 [14.1-23.6] months) showed similar results. Left atrial flutter occurred in 3% and 8% after paroxysmal AF ablation (