特发性左心室流出道心外膜侧室性心动过速

Idiopathic epicardial left outflow tract ventticular tachycardia

目的 报道 ９例经电生理检查证实的特发性左心室流出道心外膜侧室性心动过速（室速）的体表心电图及电生理检查特点。方法 男性５例，女性４例，年龄１５－５８岁，６例为运动诱发的持续性室速，３例为运动诱发的非持续性室速。结果 室速时，９例体表心电图 ＱＲＳ波全部呈现右束支阻滞图形（８例胸前导联 Ｖ１－Ｖ６呈现高 Ｒ波），Ⅱ、Ⅲ、ａＶＦ导联为高 Ｒ波，Ｉ、ａＶＬ导联为 ＱＳ波。电生理检查，右心室和左心室心内膜标测未发现最早心室激动点，在较早心室心内膜激动处的心内电图多呈现起始部低幅电位，提示远场电位。心室内起搏标测未发现与室速体表心电图１２导联ＱＲＳ波形态相同的起搏点。８例通过心脏静脉系统标测发现最早的心室激动点［体表心电图最早ＱＲＳ波前１５－５０ ｍｓ，平均（３２ ± １２）ｍｓ］和完全或近乎完全的起搏标测位于心大静脉的远端 １例、心前间隔静脉的近端７例。１例患者在左心室流出道消融成功，１例患者在心大静脉远端血管内消融成功。其他患者在右心室和／或左心室内消融失败。结论 心脏静脉标测可以鉴别出特发性左心室流出道心外膜侧室速。

Objective Nine patients (pts)who had ventricular tachycaidia (VT) originating from the subepi- cardial region of the left ventricular outflow tract were reported. Methods Five pts were male and 4 female, aged 15 - 58, presented with exercise-induced nonsustained and sustained VT in 3 and 6 pts, respectively. Results hi all pts the QRS morphology during VT exhibited RBBB morphology (8 pts exhibited tall R wave acmss the precordial leads), tall R wave in leads Ⅱ,Ⅲ, and aVF, and QS morphology in leads I and aVL. Endocardial right and left ventricular mapping did not identify the site with the earliest ventricular activation time. Electrograms at earlier endocardial sites showed low amplitude initial components suggestive of far field signals. Endocaidial pace mapping pmduced a poor QRS match with surface 12-lead ECG during spontaneous VT. Earliest ventricular activation [15 -50 ma, mean (32 ±12)ms before QRS] and nearly identical QRS morphology were obtained from pace mapping at the distal great car- diac vein in 1 Pt and from the proximal anterior interventricular vein in 7 pts who underwent epicardial mapping thmugh the cardiac veins. Radiofrequency current deliveiy in the great cardiac vein eliminated VT in 1 pt, and in the endocardium of the left ventricular oufflow tract in 1 pt. Condusion Cardiac vein mapping may identify pta with idio- pathic subepicardial left ventricular oufflow tract VT.