1Herzzentrum der Universität zu Köln Elektrophysiologie Köln, Deutschland
Background:
Premature ventricular contractions (PVC) arising from the left ventricular summit are a challenging arrhythmia to manage, often refractory to conventional radiofrequency ablation. This study aimed to investigate the effectiveness of bipolar ablation as a therapeutic option for PVCs originating from this anatomically complex region.
Methods:
We conducted a retrospective analysis of a prospective ablation registry to identify patients with recurrent, symptomatic PVCs originating from the left ventricular (LV) summit who underwent bipolar ablation. Bipolar ablation involved the use of two ablation catheters, delivering radiofrequency energy from opposite sides of the summit. The catheters were connected by a dedicated adapter, allowing to connect one ablation catheter in position of a return electrode. Procedural success was defined as the elimination of PVCs during the procedure and freedom from PVCs on follow-up monitoring. Results of procedure and follow-up were compared to a similar patient group who had received unipolar ablation of summit-PVCs.
Results:
A total of 12 patients received bipolar ablation between July 2022 and October 2023. Three pts underwent ablation for sustained VT (two LV-summit, one LV apex) and were excluded. A total of 9 patients (mean age 57±18 years, n=7 [78%] male, BMI 28±5kg/m2) were therefore included in the analysis. Two pts (22%) suffered cardiomyopathy (one DCM one NCCM) with impaired systolic LV-function (<35%). All but one had a history of a previous unsuccessful ablation attempt (median 1 [1-2]). In the group of 33 patients who underwent unipolar ablation of summit-PVCs 8 (32%) had received at least one previous ablation and were included in the analysis. Baseline parameters did not differ between groups. The acute procedural success rate for bipolar ablation was 89% (8/9 pts) in bipolar pts and 75% (6 out of 8 pts) in unipolar pts, with a mean procedural time of 173±33 minutes, a mean fluoroscopy time of 14±9 minutes (158±55 min [p=0.478] and 14±12 min [p=0.995] for unipolar pts). Bipolar ablation was performed between the LVOT and RVOT in 6, and between LVOT and the distal CS in 6 pts with 25-35 W. Coronary angiography was performed in 2 (22%) pts before and after bipolar ablation. No major complications were detected in bipolar pts while one non-fatal tamponade occurred in the unipolar pts group. Follow-up data at 97 [93-269] days revealed a sustained reduction in PVC burden in bipolar pts (from 18±13% to 7±9%; p=0.026) while unipolar ablation did not show a significant burden reduction (15±6% to 11±10%; p=0.382). The success rate of a relative burden reduction >50% was n=6 (67%) and did not differ significantly between the groups (burden reduction after unipolar ablation >50% in 3 out of 8 pts [38%]; p=0.347).
Conclusion:
Bipolar ablation offers an effective and safe therapeutic approach for PVCs originating from the LV summit in pts with failed prior ablation attempts. It significantly reduced PVC burden in this analysis, providing symptomatic relief for patients with a challenging arrhythmia. The data suggest that a repeat procedure after a failed summit PVC ablation should only be performed if bipolar ablation is available during the second procedure. Larger studies are warranted to confirm efficacy and safety of this ablation method.