Cather ablation procedures
The radiofrequency catheter ablation (RFCA) procedures were performed under conscious sedation. The detail of the procedure has been described previously13. After access to the left atrium (LA) via the transseptal puncture needle (Synaptic Medical), two 8.5 - French sheaths (NaviEase, Synaptic Medical) were advanced into LA. Intravenous heparin was administered immediately after the transseptal puncture and to maintain the activated clotting time of 250 - 350 seconds throughout the procedure. A 7-French mapping catheter (PentaRay, Biosense Webster) was used to perform the 3-dimensional electrical anatomical mapping (EAM) under the guidance of the CARTO3 system (Biosense Webster). An 8-French 3.5-mm tip irrigated ablation catheter (SmartTouch, Biosense Webster) with an upper power of 40 W, an upper temperature limit of 43°C, and a flow rate of 17 mL/min was used to perform the catheter ablation. The stepwise ablation strategy was employed: i) circumferential pulmonary vein isolation (CPVI) with bi-directional electric block as the endpoint in every patient; ii) if AF remained after CPVI, the complex fractionated atrial electrogram (CFAE) based ablation was performed; iii) if focal or reentrant atrial tachycardia (AT) was presented during the procedure, a focal or linear ablation based on the EAM and/or entrained mapping was performed; iv) if cavo-tricuspid isthmus (CTI) dependent atrial flutter (AFL) was observed before or during the procedure, linear ablation of the CTI was performed with di-directional conduction block as the endpoint; v) if AF persisted after all these ablation lesions, intravenous ibutilide and/or electric cardioversion was used to restore sinus rhythm. The detailed ablation data in catheter ablation group is shown in Table S1.