A new method for locating the ablation targets of ventricular outflow tract arrhythmias

Abstract

Objective To review the characteristics of intraoperative 12-lead intracardiac electrograms in successful ablation of ventricular arrhythmias originating from outflow tract, and to obtain a rapid and effective method for locating left and right ventricular outflow tracts, in order to effectively determine the target orientation and reduce the operation time. Methods Retrospective analysis was performed on the figures of 125 patients successfully ablated on the site of right ventricular outflow tract (RVOT) and 32 cases originating from left ventricular outflow tract (LVOT) , underwent ablation for premature ventricular contraction (PVC) or ventricular tachycardia (VT) in Sir Run Run Shaw Hospital between June, 2016 and April, 2018. The patients with ventricular arrhythmia whose V1 lead was rS or QS, and the main wave of inferior wall leads was upward electrocardiographic manifestation were selected as the research objects. We measured and analyzed the R wave amplitude and R-wave peak time (RWPT) , R-wave maximum deflection index (MDI) , R-wave amplitude index in lead V2, S-wave amplitude in lead V2 divided by R-wave amplitude in lead V3 (SV2/RV3) , S-wave amplitude in former lead of R-wave transition in precordial lead divided by R-wave amplitude in transition in precordial lead (TS/R) , transitional zone index (TZI) . Results rS or QS type in lead V1, the T S/R had the highest specificity (88%) and the R-wave maximum deflection index in lead V2 had the highest sensitivity (87.5%) whether the heart was transposed or not. The SV2/RV3 had a higher sensitivity but a lower specificity than TS/R index. Conclusion T S/R index≤1.0, indicatingLVOT ventricular arrhythmia could be used as a new high specificity index, and the R-wave maximum deflection index in lead V2≥0.3 indicated a high sensitivity of LVOT in outflow tract PVC/VT. Key words: Electrocardiography; Arrhythmias, cardiac; Catheter ablation