Reviewing Strategies and Our Approach to Mapping and Ablation of Left Ventricular Summit Arrhythmias

Background: Left ventricular (LV) summit is an important origin for ventricular arrhythmias (VAs). However, the complex electroanatomic structure of LV summit and the surrounding anatomic sites makes ablation of this arrhythmia challenging. Aim: In this paper, we review the main strategies to mapping and ablation of LV summit VAs and summarize our experience in this challenging ablation. Methods: To summarize our experience, we included all consecutive patients with outflow VAs referred to our institute for ablation between 2019 and 2024 who were eventually diagnosed with LV summit origin based on electroanatomical mapping and ablation result using stepwise and sequential ablation approach. Results: A total of 38 patients were found to have VAs from LV summit origin. Overall five patients had history of at least one failed ablation. V1 transition was seen in 15 patients, V2 transition in 12 patients, and V3 transition in 11 patients. Four patients had R wave pattern break in lead V2. Ablation was performed from the earliest activation or from one of the adjacent sites using stepwise and sequential approach. Acute suppression of VAs occurred in 35 patients without complications, except one case of pseudoaneurysm of femoral artery. Conclusions: Stepwise and sequential ablation approach can suppress VAs originating from LV summit in most patients.