Abstract 16306: Characteristics of Left Ventricular Summit Ventricular Arrhythmias Ablation - The Inaccessible Peak

Abstract

Introduction: Ventricular arrhythmias (VA) arising from the left ventricular (LV summit) are often inaccessible especially in the region superior to the coronary sinus (CS) and ablation at multiple sites may be required. We sought to define the procedural characteristics and outcomes in this group of patients. Methods: Consecutive patients who underwent ventricular premature beat (VPB) ablation at our academic center were obtained. Patients with VPBs arising from the LV summit were noted and their charts were reviewed for clinical and procedural characteristics. Results: There were a total of 110 patients who underwent VPB ablation between January 2012 to March 2015. Of these there were 13 patients whose VA site of origin was determined to be from the LV summit intra-procedurally. Mean age of the patients was 53±16 years with 85% whites and 54% males. Mean QRS duration was 117±33ms. 11 patients were on a beta-blocker, 1 on a class Ia agent and 2 on no medications. Mean EF pre and post procedure was 41±14% and 47±10%. Mean PVC burden was 26%. EKG morphology showed LBBB pattern pattern in V1 with transition in V3 (in 6 patients), RBBB pattern (7 patients) with inferior axis and negative lateral leads. Mean procedure and fluoroscopic times were 266±82 and 45±20 minutes respectively. Acute success was obtained in 69% (n=9) and partial success in 15% (n=2). Acute success was obtained by ablating in the CS alone in 3 patients, epicardially alone in 3 patients and endocardially in 1 patient. In the other 2 patients, epi and endocardial ablation was performed in 1 patient and endo, epi and CS ablation in the other patient to obtain acute success. In the 2 patients with partial success, epicardial and CS ablation in 1 patient and endocardial and CS ablation in the other was performed. In one patient no ablation was performed and in another patient ablation was performed in all 3 sites without any success. Long term recurrence > 3 months occurred in 1 patient with acute success. A power of 30 to 50 watts was used in the CS, 30 to 45 watts in the epicardium and 30 to 50 watts in the endocardium. Conclusion: Epicardial or CS ablation alone was successful in terminating VPBS arising from the LV summit in about half of the patients with epicardial and/or endocardial and/or CS ablation required in few others.