P4763High power radiofrequency ablation with fixed short duration is rapid, efficient and safe for circumferential pulmonary vein isolation

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Abstract Background Short duration 50 Watt radiofrequency (RF) ablation has been shown to be feasible for atrial fibrillation (AF) ablation with short procedure times. Purpose We evaluated 50 Watt RF power with a different fixed short application duration at the anterior and posterior left atrial wall using contact force (CF) sensing catheters for circumferential pulmonary vein isolation (PVI). Methods Consecutive patients (pts) with indication for de novo AF ablation (n=40, age 64±12 years) with paroxysmal (n=23) or persistent (n=17) AF underwent high density 3D mapping of the left atrium. Low voltage areas of more than 5% of the left atrium were only found in 20% of pts. Thereafter, circumferential PVI using CF sensing catheters was performed. For each RF application (50 Watt, RF duration 11–13s at the anterior wall, 9–11s at the posterior wall) a stable catheter tip position with minimal mean CF of 3g was required and application was stopped in case of CF more than 30g. Esophageal temperature measurement was performed with temperature cut off 39.0°C. In case of temperature rise, ablation protocol was switched to conventional 20 Watt RF applications for ablation adjacent to the esophagus. Results Complete PVI was achieved in all pts with 81±29 short RF applications resulting in cumulative RF applications duration of 13.1±4.2min and an ablation duration of 59±17min for complete PVI. Even RF application with low CF (3–5g) were effective. Due to esophageal temperature rise, switch to conventional RF application with 20 Watt was performed in 43% of pts at least at one posterior PV entrance. After a waiting period of 20 min only in 33% of pts any PV conduction recurs, in 28% of pts only at a single spot and reconnected fibers were not associated with low CF application at that spot, but clearly associated with low energy application at the posterior wall. All PV were successfully re-isolated in most of pts with a single spot high energy RF application. No serious complications occurred in association with PVI. Follow up will be available at presentation time. Conclusion RF ablation with 50 Watt fixed short duration is efficient and safe for circumferential PVI. Ablation procedure durations are shorter and early recurrence rates are lower compared to reported conventional ablation procedures. The importance of CF titration seems to be diminished by 50 Watt RF applications in the left atrium. Further follow up have to be waited.