CBA
All procedures were performed under deep sedation with propofol. A 15-Fr steerable sheath (FlexCath Advance; Medtronic, Ireland) was introduced into the LA, and an inner lumen mapping catheter (Achieve; Medtronic, Ireland) was sequentially positioned in each PV to obtain the baseline PV potential. A 28-mm CBA (Arctic Front Advance or Arctic Front Advance PRO, Medtronic, Ireland) was advanced over the inner lumen mapping catheter up to the LA, inflated, and positioned in the PV ostium of each vein. The CBA was inflated and advanced to the ostium of each PV in an attempt to obtain complete occlusion. After verifying the complete occlusion of the PV ostium, cryoenergy was applied. After documentation of the PVI, the freeze cycle was extended for another 120 seconds. If no real-time PV signal recording could be obtained, a standard freeze cycle of 180 seconds was applied.10 In cases with either a minimum temperature of ≤ -60℃, an esophageal temperature of <18.5℃, or the PV potential remained after a 100 second application of cryoenergy, CBA was discontinued.11 If the PV potential did not disappear after several applications at the same PV, touch-up ablation with a 4-mm-tip irrigated ablation catheter (FlexAbility™ Ablation Catheter, Abbott, Chicago, IL) was performed. To avoid phrenic nerve injury, CBA applications for the right PVs were performed under monitoring of the diaphragmatic compound motor action potentials during phrenic nerve pacing.12