OBJECTIVES The aim of this study was to determine the mechanism of atrial tachycardia (AT) that occurs after ablation of atrial fibrillation (AF). BACKGROUND Patients who undergo catheter ablation of AF may develop AT during follow-up. METHODS Seventy-eight patients underwent an ablation procedure for AT after circumferential pulmonary vein ablation (CPVA) for AF. The 3-dimensional maps fro...