A new insight into the anatomical ablation approach at R-L ILT for VAs with a left ventricular summit origination: electrophysiological characteristics and catheter ablation

Ventricular arrhythmia (VA) originating from the left ventricular summit (LVS) poses particular challenges, with higher rates of ablation failure. To further evaluate the anatomical ablation approach from the subaortic region for LVS VAs and their electrophysiological characteristics. The study enrolled 27 consecutive patients with sympatomatic VAs originating from LVS and who received an anatomical ablation approach from R-L ILT in our center. Three different mapping results were obtained as the earliest activation sites (EAS) were observed in the RVOT region (group 1), R-L ILT (group 2), and epicardial region (group 3), respectively. A higher percentage of rS/QS patterns in lead I was observed in Groups 1 and 3. A narrower QRS duration was observed in Group (1) A presystolic potential was recorded at R-L ILT for most VAs in group (2) All VAs were successfully ablated at R-L ILT in groups 1 and 2, though poor pace mapping results were observed at R-L ILT. 4/7 VAs in group 3 ultimately failed after an ablation in both the endocardial and epicardial regions. An anatomical ablation approach at R-L ILT was effective for most VAs with an LVS origin. Different ECG and electrophysiological characteristics could be observed in VAs with different EAS. Poor pace mapping results in all regions with an EAS in the epicardial region had predictive value for the failure of the ablation procedure.