The RV(1)-V(3) transition ratio: A novel electrocardiographic criterion for the differentiation of right versus left outflow tract premature ventricular complexes

BACKGROUND: Several electrocardiographic (ECG) indices have been proposed to predict the origin of premature ventricular complexes (PVCs) with precordial transition in lead V(3). However, the accuracy of these algorithms is limited. OBJECTIVES: We sought to evaluate a new ECG criterion differentiating the origin of outflow tract with precordial transition in lead V(3). METHODS: We included in our study patients exhibiting outflow tract PVCs with precordial transition in lead V(3) referred for ablation. We analyzed a novel new ECG criterion, RV(1)-V(3) transition ratio, for distinguishing right from left idiopathic outflow tract PVCs with precordial transition in lead V(3). The RV(1)-V(3) transition ratio was defined as (RV1+RV2+RV3) (PVC) / (RV1+RV2+RV3) SR (sinus rhythm). RESULTS: We included 58 patients in our study. The ratio was lower for right ventricular outflow tract origins than left ventricular outflow tract (LVOT) origins (median [interquartile range], 0.6953 [0.4818–1.0724] vs 1.5219 [1.1582–2.4313], P < .001). Receiver operating characteristic analysis revealed an area under the curve of 0.856 for the ratio, and a cut-off value of ≥0.9 predicting LVOT origin with 94% sensitivity and 73% specificity. This ratio was superior to any previously proposed ECG criterion for differentiating right from left outflow tract PVCs. CONCLUSION: The RV(1)-V(3) transition ratio is a simple and accurate novel ECG criterion for distinguishing right from left idiopathic outflow tract PVCs with precordial transition in lead V(3).