The V1 transition ratio: electrocardiographic criterion for predicting the success of ablation for outflow tract premature ventricular contractions

FUNDING ACKNOWLEDGEMENTS: Type of funding sources: None. BACKGROUND: Several electrocardiographic (ECG) criteria have been proposed for distinguishing left from right ventricular outflow tract premature ventricular contractions (OTPVCs) origins. However, electrocardiographic criteria predicting successful catheter ablation (CA) for OTPVCs are still unknown regardless of right and left ventricular origins. METHODS: We enrolled 63 patients who underwent CA for OTPVCs from September 2020 to August 2022, except patients with bundle branch block and axis deviation in 12-lead ECG. Radiofrequency catheter ablation (RFCA) was performed using 3D-mapping system and irrigation catheter. Electrocardiographic parameters of successful and unsuccessful patients were retrospectively analyzed. The transition ratios were calculated by the percentage R-wave during PVC (R/R+S) PVC divided by the percentage R-wave in sinus rhythm (R/R+S) SR . Success of CA for OTPVCs was defined as absence of targeted PVCs during all follow up visits and PVC burden <5% on follow-up period. RESULTS: 54 patients (85.7%) were success and 9 patients (14.3%) were unsuccess. Age, sex, Ejection Fraction (EF) and the burden of PVCs before CA were similar between 2 group. (Age: 50±15 vs 54±12 years, p=0.51, male: 46.3 vs 53.7%, p=0.73, EF: 66(58-73) vs 69(59-74), p=0.52, burden of PVCs: 22(17-29) vs 15(13-33)%, p=0.45). V1 transition ratio of unsuccessful group was significantly higher than successful group. (0.70(0.32-1.49) vs 1.55(1.09-9.37), p=0.013) V2 and V3 transition ratios were not significantly different between the two groups. The best cutoff values of V1 transition ratio were 1.0 (AUC 0.78, 95%CI: 0.61-0.94, sensitivity 0.70, specificity 0.88). CONCLUSION: V1 transition ratio>1.0 is more likely to be associated with a higher rate of RFCA failure of OTPVCs.