RFA
After performing a transseptal puncture using a one-puncture technique, two long sheaths were inserted into the left atrium (LA).7 A pulmonary venography was performed to determine the anatomical relationships of the PV ostia and the LA. Circular mapping catheters were placed in the superior or inferior PVs, and ipsilateral PVs were circumferentially and extensively ablated under fluoroscopic and electrophysiological guidance. RFA applications were delivered using either an 8-mm-tip ablation catheter (Japan Lifeline Inc, Japan), SmartTouch ThermoCool® Surround Flow irrigated-tip ablation catheter (Biosense Webster, Irvine, CA), or TactiCath™ Quartz (Abbott, Chicago, IL). The maximum power applied on the LA posterior wall was 20-30 W and that at the anterior aspect of the PVs was 30-40 W. The RFA energy was delivered for 30–40 seconds at each site. When the CARTO system (Biosense Webster, Irvine, CA) and contact force catheter were used, RFA was delivered until the ablation index reached >400 at the posterior wall/roof and the ablation index was >450 at the anterior wall. A point-by-point RFA was performed. When the EnSite system (Abbott, Chicago, IL) was used, the lesion size index approach was conducted;8 RFA was delivered until the lesion size index was >5 at the posterior wall/roof and the lesion size index was >5.5 at the anterior wall. The esophageal temperature has been routinely measured during RFA applications to avoid esophagus-related complications.9 In cases with an esophageal temperature of >39℃, RFA was discontinued.