Bipolar radiofrequency ablation for refractory scar-related interatrial septal tachycardias: a multicenter study

Catheter ablation of scar-related interatrial septal atrial tachycardias (IAS-ATs) is challenging and can be refractory to conventional unipolar radiofrequency catheter ablation (RFCA). This multicenter study investigated the safety and efficacy of bipolar radiofrequency catheter ablation (Bi-RFCA) in patients with IAS-AT refractory to conventional unipolar RFCA. Consecutive patients with scar-related IAS-AT refractory to conventional unipolar RFA across three electrophysiological centers were included in the study. Bi-RFCA with power up to 40 W and duration up to 60 s was performed with two ablation catheters across the IAS at sites identified with activation and entrainment mapping. Acute termination and noninducibility of the targeted IAS-AT was used as the intraprocedural ablation endpoint. Arrhythmia-free survival from any atrial arrhythmia (AT or atrial fibrillation) lasting > 30 s was used as a follow-up outcome measure. A total of 17 patients (12 males, age 62 ± 13) were included in the study. Acute elimination of arrhythmia with Bi-RFCA was achieved in all patients. Mean procedure time was 173 ± 69 min, mean bipolar RF time 209 ± 193 s, and mean power 39 ± 3 W. During 11 ± 3 months of follow-up, AT/AF recurrence was observed in 2 (12%) patients. No steam pops occurred during any of the Bi-RFCA applications and no other complications occurred during procedures or follow-up. Bi-RFCA is an effective and safe strategy to target scar-related IAS-AT refractory to standard unipolar RFCA.