Bipolar Catheter Ablation as a Key for Successful Treatment of Intramural VentricuLar Arrhythmias: Results From the Bipolar-Kiel Study.

Background: Unipolar catheter ablation (CA) is effective in the treatment of ventricular arrhythmias but its efficacy can be limited in eliminating intramural arrhythmic origins. Bipolar ablation has emerged as a bail-out strategy. However, currently, it is being primarily utilized after a failed ablation attempt.

Objective: The aim of this study is to assess the safety and efficacy of endocardial and/or epicardial bipolar catheter ablation in patients with ventricular arrhythmias within their first procedure or after a previously failed ablation attempt.

Methods and results: Patients who underwent bipolar CA between September 2022 and February 2025 were included. A total of 21 bipolar ablation procedures were performed in 19 patients (median age 66 ± 11, 11% female, median ejection fraction 42% ± 16%). In total, 16 procedures were performed due to ventricular tachycardia (VT) or VT storm, five procedures were performed due to symptomatic premature ventricular contractions (PVC). In 48% of all cases, ablation was performed within the patient's first procedure. The interventricular septum was the most common site of bipolar ablation (11/21), followed by epi-endocardial bipolar ablation procedures (9/21) and the papillary muscle (1/21). Bipolar ablation was successful in 17/21 patients. In one patient, AV block occurred after bipolar ablation. During a median follow-up time of 12 ± 6 months, four patients with initially acute procedural success experienced recurrence of a ventricular arrhythmia.

Conclusion: Bipolar catheter ablation is an effective tool for arrhythmias with an intramural origin. It is shown to be safe with a high acute success rate in patients undergoing their first or redo procedure for VT or PVC.