Coupling interval variability: A new diagnostic method for distinguishing left from right ventricular outflow tract origin in idiopathic outflow tract premature ventricular contractions patients with precordial R/S transition at lead V3

Abstract

Background: To distinguish left ventricular outflow tract (LVOT) from right ventricular outflow tract (RVOT) origin in idiopathic outflow tract premature ventricular contractions (IOT-PVCs) patients with precordial R/S transition at lead V3 is still a challenge. We sought to develop a new electrocardiography (ECG) method for distinguishing LVOT from RVOT origin in IOT-PVCs patients with precordial R/S transition at lead V3.

Methods: We analyzed the surface 12-lead ECG characteristics and the difference of coupling interval variability (CIV) of PVCs between distinct origin sites in a retrospective cohort of IOT-PVCs patients with precordial R/S transition at lead V3 who underwent successful radiofrequency catheter ablation (RFCA) to develop a new diagnostic method, then validated it in a prospective cohort.

Results: A total of 196 consecutive patients (41 ± 15 years, 36.7% male) underwent RFCA of IOT-PVCs between January 2014 and August 2016. Among them, 68 patients (34.7%, 23 male) with precordial R/S transition at lead V3 constituted the retrospective cohort. Based on the areas under the receiver operating characteristic curves (AUCs), a CIV > 100 ms with the largest value of AUC was selected to develop a new diagnostic method with a specificity of 93.9% and an accuracy of 92.6%. It correctly identified the origin site of 38 from 41 patients in the prospective cohort, demonstrating a 96.8% specificity and 92.7% accuracy.

Conclusions: We presented a new simple method, a CIV > 100 ms which could reliably distinguish LVOT from RVOT origin in IOT-PVCs patients with precordial R/S transition at lead V3.

Keywords: Coupling interval variability; Electrocardiogram; Left ventricular outflow tract; Precordial R/S transition; Premature ventricular contractions.