Background: Catheter mapping in patients with paroxysmal AF has revealed atrial foci that can trigger the onset of arrhythmia. Case Report: A 68 year-old man with a 3–year history of palpitations and recurrent paroxysmal atrial fibrillation was treated by radiofrequency (RF) catheter ablation. A single source of ectopics was localized within the initial segment of left superior pulmonary vein (LSPV), witch gave rise of conducted repetitive and non-sustained discharges. Successful ablation site was situated in the ostial point of the LSPV almost in left atrium where fusion of rapid potential with left atrial potential was founded, but not to the site where the earliest rapid potential was identified. Conclusions: Specific successful ablation site can be guided using simple electrophysiologic criteria for specific localization of emerging point of PVPs from pulmonary vein to left atrium.

Keywords: Atrial Fibrillation, pulmonary vein ectopics