Background: Transient reconduction of the isolated pulmonary veins (PVs) induced by an intravenous injection of adenosine triphosphate (ATP) is known to be a surrogate marker of subsequent reconnection of the PVs after catheter ablation (CA). And reapplication of ablation in these atrial fibrillation (AF) patients may increase the success rate of complete PV isolation during follow up. It remains to be determined whether reconnection of PV potential (PVP) post-ATP is different between those with dissociated PVP and complete elimination of PVP and whether the impact of further ablation guided by ATP on the outcome of CA is different or not. The aim of this study was to investigate the effect of ATP on the dissociated PVP and the impact on the recurrence rate of AF by reapplication of ablation at the earliest reconnection PVP site demonstrated by ATP injection. Methods: This study comprised 16 patients (11 men, 54.1짹13.0 years old) with AF patients who showed dissociated PVP after successful PV isolation and underwent adenosine (12mg) guided additional ablation at the reconnection of PVP site, ATP (+) group. We compared clinical characteristics and the recurrence rate of 91 patients (72 men, 55.4짹9.7 years old) who showed dissociated PVP after ablation, but did not undergo injection of adenosine, ATP (-) group. The portion of persistent AF was 18.8% in ATP (+) group and 28.6% in ATP (-) group (p= 0.6). Follow up period was 7.6짹2.1 month in ATP (-) group and 8.6짹8.4 month in ATP (+) group, respectively (p= 0.3). Results: The LA size (40.6짹6.6 mm) and LA volume (96.7짹32.2 mm3) in ATP (-) group were similar to those of ATP (+) group (37.8.짹3.7 mm and 82.8짹19.4 mm3, p=0.1 and p=0.1, respectively). The left ventricular ejection fraction in ATP (-) group was 55.2짹5.3% and 56.0짹5.9% in ATP (+) group (p=0.6). Anti-arrhythmic drugs were used after CA in 44% out of ATP (-) and 37.5% out of ATP (+) group respectively (p= 0.63). Twenty seven (29.7%) out of 91 patients in the ATP (-) group recurred AF, whereas only 1 (6.3%) of 16 ATP (+) group recurred (p= 0.049). Conclusions: After PV isolation, reapplication of ablation guided by ATP injection in patients with dissociated PVP significantly reduced AF recurrence rate. Keywords: Dissociated potential, Dormant potential, adenosine triphosphate (ATP)