Abstract 17592: Radiofrequency Catheter Ablation of Para-Hisian Ventricular Arrhythmias: Features of the Local Ventricular Electrogram at the Optimal Ablation Site
Introduction: The characteristics of the local ventricular electrogram at the optimal ablation site have been rarely described in patients undergoing catheter ablation for idiopathic ventricular arrhythmias (VAs) originating in the vicinity of the His bundle region.
Methods and Results: Among 163 consecutive patients with idiopathic VAs with left bundle branch block morphology and inferior-axis deviation, 15 patients (9%) were found to have an successful ablation site at the right ventricle close to the His bundle region (para-Hisian group). The electrophysiologic data were compared between the patients of para-Hisian group and those with VAs arising from the right ventricular outflow tract (RVOT group). The local bipolar electrogram at the successful ablation sites in the para-Hisian group exhibited a significantly longer R-wave duration, lower R-wave amplitude, and slower upright deflection of the initial R wave than did those in the RVOT group (all p<0.001). In the para-Hisian group, a total of 53 radiofrequency energy applications were delivered, of which local ventricular electrograms at 15 successful and 38 unsuccessful ablation sites were reviewed. Multiple peaks of R wave at the local bipolar electrogram were present in 14 (93%) of the successful ablation sites. R-wave duration of greater than 34 ms had discriminatory power for indicating the site of successful ablation (area under receiver operating characteristics curve 0.94, sensitivity 93.3%, specificity 81.3%).
Conclusions: The successful ablation site of para-Hisian VAs has distinctive characteristics of the local ventricular electrograms. R wave lasting longer with multiple peaks of the local bipolar electrogram could be a novel predictor of successful ablation. These findings can facilitate catheter ablation for para-Hisian VAs and reduce the risk of inadvertent atrioventricular block.
- © 2010 by American Heart Association, Inc.