起源于右室流出道间隔部特发性室性早搏心电图及心电向量图研究

目的：探讨经射频消融证实的起源于右室流出道间隔部的特发性室性早搏（室早）的心电图特征及心电向量图特征。方法采用 CARDIO-View 心电工作站收集并分析14例经射频消融术证实为右室流出道间隔部特发性室早患者的12导联心电图及 Frank 导联心电向量图参数。结果起源于右室流出道间隔部的特发性室早呈类左束支阻滞图形。12导联心电图胸导联移行指数≥0的有12例（85．7％），V2导联 R 波时限指数＜50％的14例（100％）， V2导联 R／S 波振幅指数＜30％的有13例（92．9％），SV2／RV3指数＞1．5的有12例（85．7％）。心电向量图特征为：QRS 环运行方向在 F 面呈 CW 和 CCW 的各有5例（35．7％），H 面呈 CCW的有10例（71．4％），S 面均呈 CW（100％）；起始0．04 s，QRS 环振幅逐渐增大，QRS 环方位大部分指向左前下；0．01～0．04 s 向左向量逐渐增加，向前向量逐渐减少；QRS 环最大向量及大部分面积位于左下后。结论心电图对起源于右室流出道间隔部的室早定位诊断具有较高的准确率。起源于右室流出道间隔部的室早有典型的心电向量特征。

Characteristics of electrocardiogram and vectorcardiogram of idiopathic ventricular prema-ture contraction originating from right ventricular outflow tract septum

Objective To investigate the characteristics of electrocardiogram(ECG)and vector-cardiogram(VCG)of idiopathic ventricular premature contraction(IPVC)originating from right ven-tricular outflow tract septum(RVOTS)verified by radiofrequency ablation(RFA).Methods We collected and analyzed the parameters of 1 2 lead ECG and Frank lead VCG among 1 4 RVOTS origi-nated IPVC patients verified by RFA with CARDIO-View ECG workstation.Results In 1 2 lead ECG,RVOTS originated IPVC was shaped like left bundle branch block.There were 1 2 cases (85.7%)with precordial transition ratio≥0,1 4 cases(1 00%)with R-wave duration index <50%in lead V2 ,1 3 cases(92.9%)with R/S-wave amplitude index <30% in lead V2 ,and 1 2 cases (85.7%)with SV2 /RV3 index >1 .5.The characteristics of VCG were as follows.In F plane,QRS loop operated in a clockwise(CW)and counter-clockwise(CCW)direction in 5 cases(35.7%)re-spectively;in H plane,it operated in CCW direction in 1 0 cases(71 .4%);in S plane,its operat-ing direction was CW in all the cases(1 00%);at the first 0.04 s,the amplitude of QRS loop grad-ually increased,and most of it was oriented leftward,anteriorly and inferiorly;In the period of 0.01 0.04 s,leftward vectors gradually increased while anterior ones gradually decreased;the largest vector of QRS loop and the majority of its area was located leftward,inferiorly and backward.Con-clusion ECG is proved to have high accuracy in the location and diagnosis of RVOTS originated IPVC.Typical characteristics of VCG are found in RVOTS originated IPVC.