Safety and efficacy of bipolar RF ablation for refractory ventricular arrhythmias from the LV summit
B BanavalikarAbstract
Background
The left ventricular summit (LVS) is the most common epicardial site of idiopathic ventricular arrhythmias (VA) with a high proclivity for causing PVC-induced cardiomyopathy. Standard unipolar radiofrequency (RF) ablation in the LVS is often ineffective owing to the presence of thick epicardial fat.
Purpose
To determine the safety and efficacy of bipolar RF ablation for VA in the LV summit refractory to sequential unipolar ablation.
Methods
Patients with symptomatic idiopathic VA (VT and/or PVC) from the LVS refractory to standard unipolar RF ablation formed the study population. Activation mapping was performed in the distal great cardiac vein, aortic cusps, infra-valvular LV outflow tract as well as the right ventricular outflow tract, and sequential standard irrigated ablation was performed, starting from the earliest site of activation. Bipolar RF ablation was performed if standard irrigated unipolar ablation was unsuccessful. Bipolar ablation was performed with two irrigated ablation catheters positioned on the opposing surfaces of the earliest site of activation, initially with a power of 30W and titrated up to 50W, if necessary. All patients were closely monitored during ablation for any adverse effect.
Results
Between January 2022 and October 2025, 91 patients (mean age 51.8±15.9 years; 46 females) with LVS VA refractory to sequential unipolar ablation underwent bipolar ablation. The mean LV ejection fraction was 43±10.7%, and 37 patients had PVC-induced cardiomyopathy (LVEF <50%). Fifty-seven patients had high burden PVC with non-sustained VT, three had sustained monomorphic VT, and 31 had PVC only, with a mean 24-hour VA burden of 27.9±7.1%. Fifty-five patients had VA from the inaccessible (septal) LVS whereas in 36 patients, the PVC originated in the lateral LVS. Acute procedural success with bipolar RFA (complete elimination of the clinical VA) was achieved in 85 patients with a mean RF power of 39.7±5.3W without any untoward effect. At a mean follow-up of 25.3±17.2 months, 79 out of 91 patients (86.8%) were free from the clinical arrhythmia in the absence of any anti-arrhythmic drug.
Conclusion
Bipolar RF ablation is a safe and effective ablation technique for refractory VA from the LV summit.