Catheter Ablation -> Ventricular Arrhythmias -> Electrocardiography D-PO06 - Poster Session VI (ID 26) Poster

D-PO06-084 - Qrs Morphology Predicts Site Of Successful Ablation In Patients With Basal Posterior Septal Premature Ventricular Complexes (ID 656)

 T.R. Larsen: Nothing relevant to disclose.


Background: Idiopathic ventricular arrhythmias (VAs) including PVCs/VT from the basal postero-septal (BPS) region of the heart are rare with reported incidence of ~2%. The VAs may originate from the endocardial or epicardial aspect of the BPS region and may require ablation from adjacent cardiac chambers.
Objective: Describe ECG characteristics of BPS VAs and identify features that may predict successful site of ablation.
Methods: All consecutive patients referred for catheter ablation of VAs at our center between July 2016 and July 2019 formed the study cohort. Patients who had successful ablation site at BPS were included. All patients failed at least 1 antiarrhythmic medication. The 12 lead ECG of PVCs were analyzed.
Results: Of 326 patients undergoing idiopathic VA ablation, 9 (2.7%) had successful ablation at BPS. There were 7 males, mean age 69 ± 5.8 years, mean LVEF 40 ± 12%. Mean baseline PVC burden in 8 patients was 32.3% ± 10.6% (1 patient had sustained VT). All patients had a left superior axis (LIII more negative than LII). Positive concordance (RBBB morphology in V1) predicted a successful ablation site at the basal posterior LV septum. LBBB pattern in V1 and MDI <55 predicted successful site in the RV in all but 1 patient (figure). MDI > 55 predicted success from the epicardium/middle cardiac vein (MCV). 7 patients required mapping in multiple locations (RV, LV, RA, coronary sinus/MCV). 2 required only RV endocardial mapping. 3 patients required ablation at ≥2 sites in adjacent chambers.
Conclusion: QRS morphology can guide localization of BPS VAs, however due to the complexity of this region, meticulous mapping and ablation from adjacent vantage points may be necessary to eliminate these VAs