Bipolar radiofrequency catheter ablation in the treatment of 
cardiac arrhythmias - single center experience

Abstract Background Catheter ablation has emerged as a primary choice of treatment for many arrhythmias. While unipolar ablation is sufficient in the treatment of the majority of arrhythmias, its acute and long term efficacy can be limited in specific cases. In particular, eliminating intramural arrhythmic origins remains challenging, as unipolar ablation can fail to create transmural lesions. Bipolar ablation is proposed as an alternative to overcome unipolar ablation limitations. Aim The aim of the study was to assess ablation settings, safety as well as efficacy of bipolar catheter ablation in a big tertiary ablation center. Methods and Results All patients who underwent CA between September 2022 and October 2024 were screened retrospectively for bipolar catheter ablation. Sixteen patients were identified (median age 68 [61;81], 13% female, median BMI 27 [24;31], median ejection fraction 49 [36;57]). 11/16 (69%) patients underwent catheter ablation of ventricular tachycardia (VT), 5 of those patients presented with VT storm. In 5/16 (31%) patients, catheter ablation was performed due to symptomatic premature ventricular contractions. In 7/16 (44%) patients bipolar ablation was performed after a previously failed procedure (1.6 previous procedures). All procedures were performed under conscious sedation with propofol and fentanyl. In 7/16 (44%) patients, bipolar ablation of the interventricular septum was performed (Figure). In 4/16 (25%) patients, bipolar ablation was performed between coronary sinus and left ventricle (LV) and in 2/16 (13%) patients bipolar ablation was done between epicardial and endocardial LV after establishing an epicardial access. 1/16 (6%) patient underwent bipolar ablation of the lateral papillary muscle. Median number of RF applications were 8 [6;10] with a median of 180 [174;322] seconds of RF ablation time. Average impedance drop during ablation was 15 [13;17] Ohms. Total procedure time was 180 [13;17] minutes. Bipolar ablation was successful in 12/16 (75%) patients. After a mean follow up of 8 months, one patient with acute success experienced recurrence of the tachycardia. In one patient, with previously implanted pacemaker, total AV block occurred after bipolar ablation. No other peri- or postprocedural complications occurred. Conclusion Bipolar catheter ablation is an effective tool to target different arrhythmias with an intramural origin. It is shown to be safe with a relatively high acute success rate in patients presenting with VT or PVC.