Electrocardiogram Analysis Of Radiofrequency Catheter Ablation Of Premature Ventricular Contractions From The Outflow Tract

Objective:To probe the patterns and duration of electrocardiographic, the precordial lead atwhich R/S translated after PVCs and sinus rhythm originating from the left and rightventricular outflow trcat. Identify the differences in PVCs as possible guidance forcatheter ablation.Methods:ECG characteristics in112consecutive patients who conducted radiofrequencycatheter ablation of PVCs were analyzed, respectively. we evaluated the QRSduration, the amplitudes of R wave and S wave, the R/S ratio of precordial leads, R/Stranslate lead of premature ventricular contractions. Analyse the differences of ECGcharacteristics originating from different parts of PVCs. Calculate the sensitivity andspecificity of various methods.Results:There were no differences in sex, age, LVEF, heart rate and the number of PVCsin the two groups (80patients from RVOT and22patients from LVOT).There were18patients who translated at V1-V2and16patients originating fromLVOT,2patients originating from RVOT. The standard of R/S transition at V1-V2todetermine PVCs originating from LVOT was with the specificity of97.5%, thesensitivity of72.7%. There were51patients who translated at V4-V6and49patientsoriginating from RVOT,2patients originating from LVOT. The standard of R/Stransition at V4-V6to determine PVCs originating from RVOT was with thespecificity of90.9%, the sensitivity of61.3%.There were33patients who translated at V3and29patients originating fromRVOT,4patients originating from LVOT. The V2R-wave amplitude ratio(0.50±0.24vs0.26±0.10, P=0.007) and the V2transition ratio (2.69±1.18vs0.78±0.39,P=0.003) were significantly larger for LVOT PVCs compared with RVOT PVCs. Thestandard of the V2transition ratio＞1.3to determine PVCs origin from LVOT was with the specificity of96.6%, the sensitivity of100%, positive predict value80.0%,negative predict value100%.There were60patients originating from superior part of RVOT and9patientsoriginating from superior part of LVOT. RVOT PVCs were characterised by a lowerQRS duration(136.6±16.4vs149.8±7.1ms, P=0.018) and a lower R/S ratio in leadV2(0.26±0.21vs2.30±2.56, P＜0.001).There were80patients originating from RVOT and9patients originating fromsinus of Valsalva. Sinus of valsalv PVCs were characterised by a greater R/S ratio inlead V1-V3(P＜0.01for each lead).Conclusion:The specificity and sensitivity are high when the R/S transition at V1-V2todetermine PVCs origin from LVOT, as well as the R/S transition at V4-V6todetermine PVCs origin from RVOT. The V2R-wave amplitude ratio and the V2transition ratio were significantly larger for LVOT PVCs compared with RVOT PVCs.The specificity and sensitivity are high when the V2transition ratio＞1.3todetermine PVCs origin from LVOT. The specificity of identifying the origin of PVCsfrom superior part of RVOT and LVOT by R/S ratio in lead V2is high. Thespecificity of identifying the origin of PVCs from sinus of Valsalva and RVOT byR/S ratio in lead V1-V3is high.