Abstract: AIM: To investigate the relationship between autonomic nervous system(ANS) and early recurrence of atrial fibrillation(AF) after left atrium circumferential pulmonary vein ablation.METHODS: A total of 90 patients with paroxysmal AF underwent circumferential pulmonary vein ablation using CARTO system.All patients underwent 24-h ambulatory Holter monitoring and heart rate variability(HRV) analysis 3 days before and after the ablation.Patients were divided into recurrence group(n=38) and non-recurrence group(n=52) based on the postoperative Holter results,symptoms and electrocardiogram.The average heart rate(mean HR),time domain indexes(such as SDNN,SDANN,rMSSD,PNN50) and frequency domain index(such as W,LF,HF,LF/HF) of the two groups were compared.RESULTS: Electrical isolation of the pulmonary veins was achieved in all 90 patients.The parameters indicated parasympathetic and sympathetic activities decreased significantly after ablation in both groups.In non-recurrence group,indictors of parasympathetic tone were significantly lower,whereas those of sympathetic tone were higher in recurrence group.CONCLUSIONS: Vagal denervation may inhibit early recurrence of AF after left atrium circumferential pulmonary vein ablation in patients with paroxysmal AF.