How to map and ablate left ventricular summit arrhythmias

The LVS is a common source of idiopathic VAs, and catheter ablation is challenging. The origin of these arrhythmias may be the LVOT epicardium or the intramural myocardium next to the basal septum, and mapping of the proximal septal venous perforator can help to make this differentiation. LVS VAs can be eliminated by ablation from the coronary venous system or from adjacent endocardial structures, including the LCC, basal LV endocardium, or septal RVOT. Ablation from the endocardium is preferred when an intramural origin is suspected or when ablation from the GCV/AIV is unsafe because of close proximity to coronary vessel or not technically feasible because of size or branching.