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

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

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（RV0T)和左室流出道（L0VT)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RV0T与14例起源于LV0T的室早患者一般情况无显著差异。RV0T室早比LV0T室早时限更短（P<0.05)，R/S转换在Vi?乂2导联的有12例，其中LV0T11例，特异性91.67%，敏感性78.57%;转换在V3导联的24例，其中RV0T21例，特异性87.50%，敏感性38.89%;转换在V4?乂6导联的为32例RV0T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RV0T室早的定位价值低于对LV0T室早的定位价值（P<0?05)。结论R/S转换在乂2或V2之前对LV0T的诊断价值大；转换在乂4或乂4之后对R0VT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。

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 radiofrequency ablation target. Results There was no significant difference in general circumstances between 54 RVOT-PVC and 14 LVOT-PVC patients. The duration of RVOT-PVC was shorter than that of LV0T-PVC(P <0. 05). There were 12 cases with R/S switch in Vi - V2 lead, including 11 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 sensibility of 38. 89% ; there were 32 RVOT-PVC cases with R/S switch in V4_ V6 lead with a specificity of 100% 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. 0 5 ). 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 duration index and R wave amplitude index of V2 lead play important roles in identifying the origin sitesof PVC.