Abstract Background Rotors are the source of atrial fibrillation (AF). However, the ablation of rotors for persistent AF is challenging. The purpose of this study was to identify the dominant rotor by accelerating the organization of AF using a sodium channel blocker and detecting the rotor's preferential area that governs AF. Methods Overall, 30 consecutive patients with persistent AF who underwent pulmonary vein isolation and still sustained AF were enrolled. Pilsicainide 50 mg was administered. An online real‐time phase mapping system (ExTRa Mapping™) was used to identify the meandering rotors and multiple wavelets in 11 left atrial segments. The time ratio of non‐passive activation (%NP) was evaluated as the frequency of rotor activity in each segment. Results Conduction velocity became slower—from 0.46 ± 0.14 to 0.35 ± 0.14 mm/ms (p = .004)—and the rotational period of the rotor was significantly prolonged—156 ± 21 to 193 ± 28 ms/cycle (p