BACKGROUND: Idiopathic ventricular arrhythmias (VAs) originating from the left ventricular summit (LVS) can be ablated from some endocardial sites across the left ventricular myocardium where ventricular activation is later than in the great cardiac vein (GCV) (anatomical approach). Failure of ablation at the initial target site was, however, common and approaches have evolved to improve the outcomes.
OBJECTIVES: This study explored predictors of successful anatomical ablation of LVS VAs to elucidate the ablation site selection strategy.
METHODS: We studied 40 consecutive patients who underwent a successful anatomical ablation of idiopathic LVS VAs with completed endocardial mapping.
RESULTS: The earliest ventricular activation relative to the QRS onset in the endocardium and GCV was -1 (-5 to 0) ms and -24 (-29 to -18.25) ms, respectively. Endocardial radiofrequency catheter ablation (E-RFCA) was performed at the shortest distance from the epicardial earliest activation site (EAS) in 36 patients, and it was successful in 20, in whom the endocardial earliest ventricular activation was also recorded at the ablation site. That approach failed in 16 patients, and E-RFCA was successful at the junction between the left and right coronary cusps in 3. In 13 out of 16 patients with a failed ablation and the remaining 4 patients, E-RFCA was successful at or near the endocardial EAS. Overall, E-RFCA was successful at the endocardial EAS in 37 out of 40 patients (93%).
CONCLUSIONS: This study suggests that E-RFCA of LVS VAs through an anatomical approach should first target the endocardial EAS rather than sites anatomically closest to the epicardial EAS.
Editor-in-Chief
Kalyanam Shivkumar, MD, PhD, FACC
CME Editor
Kenneth A. Ellenbogen, MD, FACC
Authors
Takumi Yamada, MD
G. Neal Kay, MD
Important Dates
Date of Release: April 27, 2026
Term of Approval/Date of CME/MOC Expiration: April 26, 2027