流出道起源室性早搏心电图特征及其对射频消融靶点的判断价值

目的：研究室性早搏（室早）的心电图特征及对流出道室早的定位价值。方法回顾68例成功消融的右室流出道（RVOT）和左室流出道（LOVT）室早患者的图形，测量胸前导联 R／S值、R／S 转换部位、V2导联 QRS 波时限、V2导联 R 波振幅指数和 R 波时限指数，探讨其与射频消融靶点的关系。结果54例起源于 RVOT 与14例起源于 LVOT 的室早患者一般情况无显著差异。RVOT 室早比 LVOT 室早时限更短（P ＜0．05），R／S 转换在 V1～V2导联的有12例，其中LVOT 11例，特异性91．67％，敏感性78．57％；转换在 V3导联的24例，其中 RVOT 21例，特异性87．50％，敏感性38．89％；转换在 V4～V6导联的为32例 RVOT 患者，特异性100％，敏感性59．26％；V2导联 R 波振幅指数和时限指数对 RVOT 室早的定位价值低于对 LVOT 室早的定位价值（P ＜0．05）。结论R／S 转换在 V2或 V2之前对 LVOT 的诊断价值大；转换在 V4或 V4之后对 ROVT 的诊断价值大；对于 R／S 转换在 V2～V3导联时，V2导联 QRS 波时限、R 波时限指数和 R 波振幅指数三个指标对确定室早的起源部位具有重要的价值。

ECG characteristics of outflow tract originated premature ventricular contraction and their location value for radiofrequency ablation target

Objective To explore the ECG characteristics of premature ventricular contraction (PVC)and their location value for outflow tract originated PVC.Methods Retrospective analysis was performed on the figures of 68 successfully ablated cases with right ventricular outflow tract (RVOT)PVC or left ventricular outflow tract (LVOT)PVC.We measured R/S value of precordial leads,switch site of R/S,QRS complex duration of V2 lead,amplitude and duration indices of R wave in V2 lead,and then discussed the relationship between each of the above index and radiofre-quency ablation target.Results There was no significant difference in general circumstances be-tween 54 RVOT-PVC and 1 4 LVOT-PVC patients.The duration of RVOT-PVC was shorter than that of LVOT-PVC(P <0.05 ).There were 1 2 cases with R/S switch in V1 V2 lead,including 1 1 LVOT-PVC ones with a specificity of 91 .67% and a sensibility of 78.57%;there were 24 cases with R/S switch in V3 lead,including 21 RVOT-PVC ones with a specificity of 87.50% and a sen-sibility of 38.89%;there were 32 RVOT-PVC cases with R/S switch in V4 V6 lead with a specific-ity of 1 00% and a sensibility of 59.26%.The location value of amplitude and duration indices of R wave in V2 lead for RVOT-PVC was low than that for LVOT-PVC(P <0.05).Conclusion R/S switch has greater diagnostic value for LVOT-PVC in or before V2 lead and for RVOT-PVC in or before V4 lead.When R/S switches in V2 V3 lead,the three indices of QRS complex duration,R wave du-ration index and R wave amplitude index of V2 lead play important roles in identifying the origin sites of PVC.