Zhang RF, Ma CM, Wang N, et al. - This investigation was carried out to define the apt initial dosage of heparin during radiofrequency catheter ablation (RFCA) among patients suffering from atrial fibrillation (AF) taking uninterrupted nonvitamin K antagonist oral anticoagulant (NOAC) treatment. This analysis involved 187 consecutive AF patients who had their first RFCA. An initial heparin dose of 100 U/kg was given in the warfarin group (control group: n = 38). Patients receiving NOACs were randomly split into 3 NOAC categories (NG: n = 149), NG110, NG120, and NG130, and were given initial heparin doses of 110 U/kg, 120 U/kg, and 130 U/kg, respectively. According to findings, an adequate intraprocedural anticoagulant effect can be offered by an initial heparin dosage of 120 U/kg or 130 U/kg for patients with AF on uninterrupted NOAC treatment who had RFCA, and dosage of 130 U/kg permitted activated clotting time to reach the target earlier.