Electrocardiographic Characteristics Differentiating Epicardial Outflow Tract-Ventricular Arrhythmias Originating From the Anterior Interventricular Vein and Distal Great Cardiac Vein

Abstract

Background:The aim of this study was to identify the ECG features that might differentiate between anterior interventricular vein (AIV) and distal great cardiac vein (d-GCV) outflow tract-ventricular arrhythmias (OT-VAs).Methods and Results:Radiofrequency catheter ablation was performed in 13 of 375 patients (3.5%) for AIV or d-GCV OT-VAs. We grouped the 13 patients by the origin, d-GCV (n=9) or AIV (n=4), and compared their ECGs and electrophysiological data. The OT-VA ECGs had S waves in lead I in all 13 patients. The voltage in the inferior lead III and peak deflection index showed no significant between-group differences (2.3±0.7 vs. 2.5±0.3 mV and 0.65±0.04 vs. 0.68±0.04 mV, respectively) for the d-GCV and AIV groups. There were also no significant between-group differences in the QaVL/QaVR, where Q denotes the amplitude of the Q wave in the suffix lead. However, the R/S ratio in V1 (1.7±1.0 [n=5] vs. 0.2±0.05, P=0.04), and QRS duration (149±16.6 vs. 123±3.8 ms, P=0.012) were greater in the d-GCG group than in the AIV group. There were no significant between-group differences in the activation time or pace mapping score at the optimal ablation sites.Conclusions:A low R/S ratio in V1 and shorter QRS duration may help identify AIV sites of epicardial OT-VA origin.