Ablation Procedure
We performed all RFCA procedures under deep sedation. A duo-decapolar electrode catheter (BeeAT, Japan Lifeline, Tokyo, Japan) was inserted into the coronary sinus (CS) from the right internal jugular vein. Two long sheaths (Swarts and Agilis, Abbott, St. Paul, MN) were advanced into the left atrium through a single transseptal puncture via the right femoral vein. A duo-decapolar ring catheter (Lasso, Biosense Webster, Irvine, CA) was used to record pulmonary vein (PV) potential. Patients were anticoagulated with intravenous heparin to maintain an activated clotting time > 300 seconds. All patients underwent circumferential PVI by isolating the left and right PVs as ipsilateral common ostia on the 3D-geometry of the left atrium (Carto 3, Biosense Webster). In patients with a long superior vena cava (SVC) sleeve (> 30 mm) or in whom ectopic beats originating from the SVC triggered AF, electrical isolation of the SVC was performed as previously described.5Isolation of the posterior wall of the left atrium (PLA) was performed depending on the operators’ discretion.6
In the Non-CF group, ablation was performed with a 3.5-mm tip, 56-hole irrigated catheter (THERMOCOOL SF; Biosense Webster). In the CF group, a 3.5-mm tip, 56-hole irrigated catheter with a CF sensor (THERMOCOOL SMARTTOUCH SF, Biosense Webster) was used for ablation. Power settings were 25–30 W for the posterior wall and 30–35 W for other regions of the left atrium. In the Non-CF group, the RF current was delivered for 20–40 seconds to each lesion, until local bipolar electrograms decreased. If intra-esophageal temperature rose > 39.5℃ during ablation, RF delivery was interrupted.