左心室流出道及邻近结构室性心律失常体表心电图鉴别流程

Differentiation procedures of superficial electrocardiogram for ventricular arrhythmias of left ventricular outflow tract and of adjacent structures

目的探讨左心室流出道(LVOT)及其邻近结构不同起源室性心律失常(VAs)的心电图(ECG)特征及鉴别流程。方法将272例射频消融成功,经X线或三维标测证实有效靶点在LVOT及其邻近结构的VAs患者纳入本研究,并分为以下6组:(1)左冠窦(LCC)组110例;(2)右冠窦(RCC)组35例;(3)左右冠窦交界处(L-RCC)组16例;(4)左冠窦下(ILCC)组42例;(5)二尖瓣环前壁心内膜(end-MAA)组18例;(6)心大静脉远端移形区(DGCV)组51例。比较LVOT及其邻近结构不同部位VAs的ECG特征,以鉴别指标的灵敏度、特异度、阳性及阴性预测值为依据制定诊断流程。结果(1)以假性δ波时间≥54ms作为鉴别DGCV与LCC、RCC、L-RCC、ILCC和end-MAA的指标,其灵敏度86.27%,特异度90.95%,阳性预测值68.75%,阴性预测值96.63%。(2)以Ⅰ导联呈R、Rs或r型作为诊断RCC及L-RCC和心大静脉远端延伸支(EDGCV)的指标,其灵敏度、特异度、阳性及阴性预测值分别为92.16%、81.18%、59.47%、97.87%和66.67%、97.62%、85.71%、93.18%;(3)以V1及V4~V6导联均呈单向R波作为诊断ILCC或DGCV2的指标,其灵敏度、特异度、阳性及阴性预测值分别为73.81%、97.21%、86.11%、94.05%及84.62%、94.74%、84.62%、94.74%;(4)以V1呈R型、V4~V6呈Rs型作为诊断DGCV1的指标,其灵敏度、特异度、阳性及阴性预测值分别为90.91%、97.50%、90.91%、98.90%;(5)以V1呈qr S或QS型作为诊断L-RCC起源的指标,其灵敏度100.00%、特异度96.59%、阳性预测值69.57%、阴性预测值100.00%。结论LVOT及其邻近结构VAs并非罕见,体表12导联ECG对其鉴别有较大的临床价值,认识这些特点,对术前初步判断可能的有效靶点,缩短手术时间及X线曝光时间有一定的意义。

Objective To explore the electrocardiographic features and differentiation procedures of left ventricular outflow tract(LVOT)and its adjacent structures with different premature ventricular premature contractions(PVCs)/ventricular tachycardia(VT)of different origins.Methods Two hundred and seventy two patients underwent successful radio-frequency ablation on targets in the left ventricular outflow tract(LVOT)and PVC/VT of its adjacent structures,which were proved by X-ray or three-dimensional standard measurement.The fuci were located in the left coronary cusp(LCC group,n=110),the right coronary cusp(RCC group,n=35),the junction of the left and right coronary cusps(L-RCC group,n=16),the inferior left coronary cusp(ILCC group,n=42),the endocardium of mitral annulus anterior wall(end-MAA group,n=18),and the distal gradual change area of great cardiac vein(DGCV group,n=51).The ECG characteristics of VAs in different parts of LVOT and its adjacent structures were compared,and the diagnostic procedure was based on sensibility,specificity,positive predictive value and negative predictive value of the differential indexes.Results The pseudo-δwave time≥54 ms was used as a index to differentiate the DGCV from LCC,L-RCC,ILCC and end-MAA,the sensibility,specificity,positive predictive value and negative predictive value were 86.27%,90.95%,68.75%,and 96.63%,respectively.Types of R,Rs or r in I lead were used as a index to diagnose RCC,L-RCC and EDGCV,the sensibility,specificity,positive and negative predictive values were 92.16%,81.18%,59.47%,97.87%and 66.67%,97.62%,85.87%,93.18%,respectively.Wave one-way R in both V1 and V4~V6 leads was used as a index to diagnose the origin of ILCC or DGCV2,the sensibility,specificity,positive and negative predictive value were 73.81%,97.21%,86.11%,94.05%and 84.62%,94.74%,84.62%,94.74%,respectively.Type of R in V1,type of Rs in V4~V6 leads were used as a index to diagnose the origin of DGCV1,the sensibility,specificity,positive and negative predictive values are 90.91%、97.50%、90.91%、98.90%,respectively.The type of qrS or QS in V1 lead was used as a index to diagnose the origin of L-RCC,the sensibility was 100.00%,specificity was 96.59%,positive predictive value was 69.57%,and negative predictive value was 100.00%.Conclusion LVOT and PVC/VT of adjacent structures are not rare,superficial 12 leads electrocardiogram has great clinical value in differentiating LVOT and PVC/VT of adjacent structures,the understanding of these characteristics has certain significance for preoperative determination of possible effective targets,shorten operative time and X-ray exposure time.