Ablation procedure
Anti-arrhythmic drugs (AADs) were discontinued for at least five half-lives prior to ablation. Oral anticoagulant drugs were skipped just before the procedure. EnSite NavxTM (Abbott, St Paul, MN, USA) was used to perform all ablation procedures. The ablation strategy consisted of liner ablations, including the roof, bottom, and MI, as well as pulmonary vein (PV) and superior vena cava (SVC) isolation under general anesthesia. The CS was cannulated using a guiding catheter (CPS AimTM SL; Abbott) via an approach from the internal jugular vein. Subsequently, a contrast agent was injected through BermanTM angiographic catheter (Teleflex, Morrisville, NC, USA) while a balloon was being inflated (Figure 2A). If angiography adequately confirmed the VOM, then EIVOM was performed in advance of RF ablation.
In both groups, an irrigation catheter (FlexiAbilityTMor TactiCathTM; Abbott) was used to deliver RF pulses (30 W, 40 s) point-by-point at the endocardium of the lateral MI under left atrial appendage (LAA) pacing (Figure 2E). The ablation catheter was supported by steerable introducer (AgilisTM NxT steerable introducer; Abbott) to gain adequate contact force and stability. If a bidirectional block line was not fully achieved, additional RF pulses (25 W, 30 s) via approaches from the femoral and internal jugular veins were delivered to the inside of the CS, which was opposite the endocardial MI line. (Figure 2F & G) Bidirectional block was confirmed by a differential pacing maneuver from the distal and proximal CS sites.