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Objectives: The purpose of this study was to assess the efficacy and safety of a novel, multielectrode, duty-cycled radiofrequency ablation (RFA) system for long-standing persistent atrial fibrillation (AF). Background: RFA for persistent AF remains a lengthy and challenging procedure. Methods: In 5 European centers, 50 patients with long-standing persistent AF underwent RFA. A circular pulmonary vein (PV) ablation catheter was used for PV isolation. Complex fractionated atrial electrograms were targeted at the interatrial septum using a multiarray septal ablation catheter and in the left atrium using a multiarray ablation catheter. Results: During a mean total procedure time of 155 ± 40 min, complete PV isolation and complex fractionated atrial electrogram ablation were achieved in all patients. In 50% of patients, redo ablation was performed using the same strategy and technology. There were no device-related adverse events. At 6 months, a 7-day Holter electrocardiogram showed >80% AF reduction in 40 of 50 patients (80%), and 32 of 50 (64%) were off antiarrhythmic drugs. At 20 ± 4 months after the last procedure, 31 of 47 patients (66%) had a >80% reduction in AF burden, with 21 patients (45%) free of AF and off antiarrhythmic drugs. Conclusions: This initial 50-patient multicenter study demonstrates a 80% short-term and 66% success rate at 20 months, with a low complication rate and a relatively short procedure time in patients with persistent AF using 3 anatomically specific multielectrode ablation catheters and low-energy duty-cycled radiofrequency energy. [Copyright &y& Elsevier]

Abstract: 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 2008DC 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 1.08DC RFA procedures per patient in 82% and after 1.19 conventional procedures in 87% after 8.5±6.5months (ns). In persistent AF, success rates were 79% after 1.35DC RFA procedures and 80% after 1.34 conventional procedures after 11.5±8.5months (ns). The subgroup analysis of 119 patients with follow-up ≥12months (17.5 [14.1–23.6] months) showed similar results. Left atrial flutter occurred in 3% and 8% after paroxysmal AF ablation (p <0.05) and in 12% and 23% after persistent AF ablation (p =0.1). Multivariate predictors for success in both groups were age, left atrial size, presence of persistent vs. paroxysmal AF and previous pacemaker implantation, but not the ablation technique used. Non-fatal complications were seen in 2.8% with no differences between the groups. Conclusion: Outcome in DC RFA is similar to conventional RFA with a final success rate exceeding 80% in both paroxysmal and persistent AF in the absence of fatal complications. [Copyright &y& Elsevier]