Electrocardiographic characteristics for successful radiofrequency ablation of right coronary cusp premature ventricular contractions.

Electrocardiographic (ECG) criteria identifying right- and left-sided outflow tract origins have been established. The purpose of this study was to define the criteria for premature ventricular contractions (PVCs) originating from the right coronary cusp (RCC) adequately.We analyzed ECG and electrophysiologic study data from patients who underwent successful ablation of PVCs originating from the RCC and right ventricular outflow tract (RVOT). Eighteen RCC and 28 septal RVOT PVCs were studied. Among these 18 successful RCC PVCs, a predominantly positive QRS in lead I in 18/18 (100%), longer V1-2 R-wave duration (81.4 ± 31.1 vs 44.8 ± 7.0 ms, P = .02), V1-2 R wave duration index (RWDI) (51.3 ± 22.0 vs 31.2 ± 7.5%, P = .06) were observed compared to those with posteroseptal RVOT. Local ventricular activation time preceding QRS onset was significantly earlier (-38 ± 12 ms) at the successful RCC ablation site compared to the failed ablation site of the septal RVOT (-22 ± 8 ms), even without good pace mapping at the RVOT (P < .001). The receiver operating characteristic curve showed that a pre-QRS time of ≥-31 ms predicted successful RCC ablation with 67% sensitivity and 94% specificity. A predominantly positive QRS in lead I, longer R-wave duration and RWDI in lead V1 or V2 with a local ventricular activation preceding QRS onset by an average of -31 ms suggests an effective RCC ablation site.