An ECG Sign of Idiopathic Ventricular Tachycardia Ablatable From the Distal Great Cardiac Vein

Background Idiopathic ventricular arrhythmias (IVAs) can originate from the distal great cardiac vein (DGCV). However, inadequate distinction sometimes occurs with the use of electrocardiography (ECG) characteristics for distinguishing ventricular arrhythmias (VAs) arising from the DGCV and the adjacent left ventricle endocardium (LV ENDO). Objective The purpose of this study was to identify distinct ECG features in patients with idiopathic IVAs originating from the DGCV. Methods A total of 32 patients with IVAs originating from the DGCV were identified from a consecutive group of 874 patients undergoing IVAs ablation. The patients with IVAs from the DGCV were compared with a consecutively chosen series of 40 patients with IVAs in whom the site of origin was in the adjacent LV ENDO. Results Of these 32 patients with IVAs arising from the DGCV, 13 patients had distinct ECG characteristics compared with the LV ENDO group. Both notches in the upstroke and downstroke of the R wave in lead III were found in all 13 patients. However, the characteristic ECG pattern in lead III was found in 1 of 40 patients in the LV ENDO group. The ECG characteristic of both early notch and late notch in lead III has a sensitivity of 40.6%, a specificity of 97.5%, a negative predictive value of 67.2%, and a positive predictive value of 92.9% to predict the VAs arising from the DGCV. Conclusions The distinct ECG characteristics of VAs originating from the DGCV can help differentiate from the adjacent LV ENDO sites of origin.