Background Major atrial coronary arteries,including the sinus node artery (SNA),were commonly found in the areas involved in atrial fibrillation (AF) ablation and could cause difficulties in achieving linear block at the left atrial (LA) roof.The SNA is a major atrial coronary artery of the atrial coronary circulation.This study aimed to determine impact of the origin of SNA on recurrence of AF after pulmonary vein isolation (PVI) in patients with paroxysmal AF.Methods Seventy-eight patients underwent coronary angiography for suspected coronary heart disease,followed by catheter ablation for paroxysmal AF.According to the origin of SNA from angiographic findings,they were divided into right SNA group (SNA originating from the right coronary artery) and left SNA group (SNA originating from the left circumflex artery).Guided by an electroanatomic mapping system,circumferential pulmonary vein ablation (CPVA) was performed in both groups and PVI was the procedural endpoint.All patients were followed up at 1,3,6,9 and 12 months post-ablation.Recurrence was defined as any episode of atrial tachyarrhythmias (ATAs),including AF,atrial flutter or atrial tachycardia,that lasted longer than 30 seconds after a blanking period of 3 months.Results The SNA originated from the right coronary artery in 34 patients (43.6％) and the left circumflex artery in 44 patients (56.4％).Freedom from AF and antiarrhythmic drugs (AADs) at 1 year was 67.9 ％ (53/78) for all patients.After 1 year follow-up,79.4％ (27/34) in right SNA group and 59.1％ (26/44) in left SNA group (P=0.042) were in sinus rhythm.On multivariate analysis,left atrium size (HR=1.451,95％CI:1.240-1.697,P ＜0.001) and a left SNA (HR=6.22,95％CI:2.01-19.25,P=0.002)were the independent predictors of AF recurrence.Conclusions The left SNA is more frequent in the patients with paroxysmal AF.After one year follow-up,the presence of a left SNA was identified as an independent predictor of AF recurrence after CPVA in paroxysmal AF.