Bipolar radiofrequency ablation of refractory ventricular arrhythmias: results from a multicentre network

Abstract

Aims: Advanced ablation strategies are needed to treat ventricular tachycardia (VT) and premature ventricular complexes (PVC) refractory to standard unipolar radiofrequency ablation (Uni-RFA). Bipolar radiofrequency catheter ablation (Bi-RFA) has emerged as a treatment option for refractory VT and PVC. Multicentre registry data on the use of Bi-RFA in the setting of refractory VT and PVC are lacking. The aim of this Bi-RFA registry is to determine its real-world safety, feasibility, and efficacy in patients with refractory VT/PVC.

Methods and results: Consecutive patients undergoing Bi-RFA at 16 European centres for recurring VT/PVC after at least one standard Uni-RFA were included. Second ablation catheter was used instead of a dispersive patch and was positioned at the opposite site of the ablation target. Between March 2021 and August 2024, 91 patients underwent 94 Bi-RFA procedures (74 males, age 62 ± 13, and prior Uni-RFA range 1-8). Indications were recurrence of PVC (n = 56), VT (n = 20), electrical storm (n = 13), or PVC-triggered ventricular fibrillation (n = 2). Procedural time was 160 ± 73 min, Bi-RFA time 426 ± 286 s, and mean Uni-RFA time 819 ± 697 s. Elimination of clinical VT/PVC was achieved in 67 (74%) patients and suppression of VT/PVC in a further 10 (11%) patients. In the remaining 14 patients (15%), no effect on VT/PVC was observed. Three major complications occurred: coronary artery occlusion, atrioventricular block, and arteriovenous fistula. Follow-up lasted 7 ± 8 months. Nineteen patients (61%) remained VT free. ≥80% PVC burden reduction was achieved in 45 (78%).

Conclusion: These real-world registry data indicate that Bi-RFA appears safe, is feasible, and is effective in the majority of patients with VT/PVC.

Keywords: Advanced ablation strategies; Bipolar ablation; Premature ventricular complexes; Ventricular tachycardia.

Graphical Abstract

Figure 1

Schematic distribution (%) of Bi-RFA lesion sets in patients included in the study. LV, left ventricle; RV, right ventricle.

Figure 2

(A) Clinical PVC of a 56-year-old female after two failed extensive unipolar ablation attempts. Earliest activation preceding PVC onset by −20 ms was recorded in the great cardiac vein adjacent to the LV summit area. (B) Configuration of the catheters and their connection to the RF generator during bipolar ablation with addition of dispersive patch to deal with the return electrodes overheating of the intracardiac return electrode positioned in the GCV. In such setting, the RF current alternates between ablation catheter tip located in the LCC and both: tip of the 8 mm intracardiac return electrode in GCV and skin dispersive patch located at the anterior chest, which anatomically is the closest surface area to the LV summit region. Power was up titrated to 40 W with effective PVC elimination and no recurrence in the follow-up. Tip temperature of the GCV catheter in such configuration did not exceed 60°C. GVC, great cardiac vein; LCC, left coronary cusp.

Figure 3

(A) Clinical VT of a 39-year-old male after eight failed Uni-RFA attempts and one Bi-RFA attempt. Abrupt V3 transition pattern is suggestive for LV summit origin. During repeat Bi-RFA ablation best, although imperfect, pace mapping was found at the septal region of the LVOT area. (B) Sequential Bi-RFA preformed between the LPC, RVOT, and LVOT with the use of two flexible-tip (Flexibility, Abbott, USA) ablation catheters. (C) Impedance trends during Bi-RFA observed with D5W and NS irrigation of both ablation catheters and at different power settings. CS, coronary sinus; D5W, dextrose-5-in water; LPC, left pulmonic cusp; LVOT, left ventricular outflow tract; NS, normal saline; RVOT, right ventricular outflow tract.

Figure 4

Kaplan–Meier curves demonstrating freedom from the clinical PVCs and VT after Bi-RFA. PVC, premature ventricular complexes; VT, ventricular tachycardia.