This study aims to assess the predictive utility of unipolar and bipolar electrogram in OTVA mapping and ablation. Results: In total 152 targets in RVOT of 76 patients: (1) 104 (68.2%) locations which record the ventricular activation. (2) The average of R_amp (the amplitude of the first positive peak), N_amp (the amplitude of the nadir) and Maxslope were 0,20 ± 0,39, 3,34 ± 3,04 và 1,45 ± 1,76, respectively. (3) The average R-Ratio and D-Max (MaxSlope) were 0,09 ± 0,15 và 16,03 ± 4,95, respectively. The unipolar electrogram criteria have meaning predictive of the high-rate success target in the right ventricular outflow tract including (1) D-Max index (the highest meaning with AUC = 0.75 95% CI 0.67 – 0.83) (2) The appreance of QS morphology (the highest sensitivity of 93%), D-Max index (the highest specify of 65%). (3) Combining unipolar electrocardiographic parameters with EAT index increases the predictive value of locating the target site in ventricular arrythmia ablation initiated from the right ventricular outflow tract. Conclusions: Unipolar EGM-derived quantitative criteria demonstrated a high value for localizing the target site and can be combined with bipolar EGM characteristics to increase the success rate of OT-PVC ablation procedures.