左、右心室起源的室性早搏体表心电图定位诊断的价值

The Value of Surface ECG Differentiating the Origin of Left and Right Ventricular Premature Ventricular Contractions

目的探讨体表心电图定位诊断对于判断室性早搏(premature ventricular contractions,PVCs)左、右心室起源的价值。方法随机选择66例射频消融成功的室性早搏患者,分析其中49例右心室起源和17例左心室起源的室早患者体表心电图V2导联QRS形态、胸前导联R波移行区、V1和V2导联R/S高度、胸前导联移行区指数(transitional zone index,TZ)的差异,确定体表心电图室性早搏胸前导联移行区指数在室性早搏起源定位中的敏感性和特异性。结果右心室起源的室性早搏V2导联多呈r S型、胸前导联R波多移行于V3-V5;左心室起源的室性早搏V2导联多呈Rs型、胸前导联R波多移行于V1-V2;右心室起源室性早搏V1、V2导联的R/S高度明显小于左心室起源的室性早搏(P<0.05),而TZ明显大于左室室早(P<0.05);TZ数值对于鉴别左、右心室起源的室性早搏的灵敏度、特异度、吻合度均较高(88.23%,83.67%,k=0.64)。结论体表心电图室性早搏的V2导联QRS形态、胸前导联R波移行区、V1和V2导联R/S高度、TZ,有助于鉴别室性早搏左、右心室的不同起源,TZ对于区分左、右心室起源的室性早搏有较好的诊断价值。

Objective To explore the value of surface electrocardiogram （ECG） differentiating the origin of left and right ventricular premature ventricular contractions （PVCs）. Methods A retrospective analysis was performed in 66 patients with PVCs who had been given radio frequency catheter ablation （RFCA） successfully, including 49 patients with PVCs originated from right ventricular （RV-PVCs） and 17 patients with PVCs from left ventricular （LV-PVCs）. QRS-wave morphology on lead V2, preeordial R wave transition zone, R/S-wave amplitude ratio on lead V1 and V2, transitional zone index （TZ index） of PVCs were measured from the surface ECG of two groups. Results In RV-PVCs group, most QRS- wave morphology on lead V2 was the type of rS, precordial R wave transition occurred all after V3, while in LV-PVCs group most the type was Rs, preeordial R wave transition occurred before V2. The R/S-wave amplitude ratio on lead V1 and V2 in RV-PVCs group was significantly lower than in LV-PVCs group （P〈0.05）.The TZ index in RV-PVCs group was significantly larger than in LV-PVCs group （ P 〈0.05）. TZ index 〈 0 for predicting left ventricular origin were 88.23% in sensitivity, 83.67% in specificity, and 0.64 in goodness of fit. Conclusion QRS-wave morphology on lead V2, precordial R wave transition zone, R/S-wave amplitude ratio on lead V1 and V2, transitional zone index of surface ECG can offer great help on identifying the origin of PVCs. The TZ index can be a more useful marker for differentiating the origin of PVCs from left or right ventricular.