New electrocardiographic criteria for predicting successful ablation of premature ventricular contractions from the right coronary cusp.

Background: ECG features for predicting successful ablation sites of outflow tract (OT) premature ventricular complex (PVCs) have been previously presented, but effective predictors of right coronary cusp (RCC) remain elusive.

Methods: 106 patients (59 males, 56±14years) who underwent successful PVC ablation were studied. Various ECG patterns and measurements were analyzed to identify the unique features of RCC PVC origins. The R-wave duration index (RWDI) was calculated as a percentage by dividing the QRS complex duration by the longest R-wave duration in lead V1 or V2.

Results: Successful ablation sites were the RCC in 18 patients, the left coronary cusp (LCC) in 20, the RCC/LCC junction (RLJ) in 22, the AIV/GCV in 11 and the right ventricular outflow tract in 35. Forty-seven patients had dominantly positive forces in lead I. Among these 47 patients, 19 were ablated from the RCC (18/18, 100%), eighteen from the RVOT (18/35, 51%), five from the LCC (5/20, 25%), and five from the RLJ (6/22, 27%). The S-wave amplitude in lead aVL was significantly smaller in RCC than LCC or RLJ PVCs (0.1±0.3mV vs. 1.1±0.5mV, p<0.001). The V1-2 RWDI was significantly greater in RCC than RVOT PVCs (51.8±20.5% vs. 30.8±13.9%, p<0.001). The optimal cut-off values of <0.95mV for S-wave (area under the curve, AUC: 0.76, p<0.01) and >43.6% for R-wave duration index in V1 or V2 (AUC: 0.83, p<0.001) were determined by ROC analysis.

Conclusions: The presence of a dominant positive lead I, RWDI >43.6% and S-wave amplitude in aVL <0.95mV predicted RCC PVCs with a sensitivity of 83% and specificity of 94%.