维拉帕米敏感性特发性左心室室性心动过速的心电图特征

Electrocardiogram characteristics of verapamil-sensitive idiopathic ventricular tachycardia

目的研究维拉帕米敏感性特发性左心室室性心动过速（ILVT）的心电图特征及相关电生理特点。方法回顾性分析2012年8月至2014年3月于阜外医院心律失常中心行心内电生理检查并经导管射频消融术治疗的51例ILVT患者的心电图，依据起源部位对ILVT进行分类，记录电生理检查中ILVT的房室关系，分析相关心电图指标。结果射频消融证实左后分支起源45例，左前分支起源3例，高位间隔起源3例，电生理检查证实70．6％的ILVT无室房传导，其余29．4％则存在不同比例的室房逆传。心电图房室分离现象可见于49％的ILVT。左后分支起源的ILVT心动过速周长为（353．7±61．1）ms，QitS时限为（130．3±9．2）ms，RS间期为（57．6±9．5）ms，胸导联及aVR导联Vi／Vt均〉1，Ⅱ导联R波达峰时间为（20．4±8．7）ms，额面QRS电轴左偏占64．4％，无人区电轴占35．6％，V．导联以R及qR型为主，V6导联以rs及QS型为主，aVR导联以qR型为主。左前分支起源的ILVT，额面电轴均右偏，胸导联及aVR导联Vi／Vt均〉1，V1导联均为qR型，V6导联均为rs型。高位间隔型ILVT的QRs时限为78～102ms，房室分离现象可见于其中2例患者，余1例可见1：1逆行P波。结论激动速度相关的心电图鉴别指标对于ILVT的诊断无帮助，而无人区电轴及形态学特征则有助于正确诊断ILVT。房室分离现象在ILVT较为常见，并且是诊断高位间隔型ILVT的唯一可靠的心电图征象。

Objective To study the surface electrocardiogram （ECG） characteristics and related elec- trophysiologic features of verapamil-sensitive idiopathic left ventricular tachycardia （ILVT）, and evaluate ECG criteria for the differential diagnosis of wide QRS complex tachycardia （WCT）. Methods Retrospectively, a total of 51 patients who underwent radiofrequency catheter ablation （RFCA） with ILVT verified by electrophysi- ologic study（EPS）between August 2012 and March 2014 were included in this study. The ILVT were classified into three subgroups according to the origin verified by successful ablation. During the episodes of ILVT induced in the EPS, the atrioventricular relationship was recorded. The ECG characteristics were thoroughly analysed. Results Forty-five left posterior,3 left anterior and 3 upper septal ILVTs were verified by EPS and successful RFCA. VA conduction was observed in 29.4% induced ILVTs during EPS. Forty-nine percent surface ECG ex- hibited evidence for atrioventricular dissociation. Regarding the lINT originating from left posterior fascicular, the major ECG findings were as follows：Mean tachycardia cycle length was （353.7±61.1） ms. Mean QRS complex width was （130. 3±9. 2） ms. Mean RS interval was （57.6±9. 5） ms;Vi/Vt〉l was observed in all precordial and aVR leads. Mean R wave peak time at lead Ⅱ was （20. 4±8.7） ms. Left axis deviation was observed in 64. 4% ECG while 35. 6% exhibited axis of ＂no man＇ s land＂. Lead V1 majorly exhibited R or qR pattern. Lead V6 commonly presented rS or Qs pattern. Lead aVR predominantly demonstrated qR pattern. For the left anterior ILVT, the ECG exhibited a right deviation of frontal QRS axis with qR pattern at lead Vl and rS pattern at lead V6. The upper septal type consistently exhibited narrow QRS tachycardia. In addi- tion, atrioventricular dissociation was observed in two of three ECGs in the subgroup of upper septal ILVT, leav- ing one case presenting 1 ： 1 retrograde P wave. Conclusion WCT differential criteria related with conduction velocity fails to predict ILVT reliably. Axis of ＂no man＇ s land＂ and morphology criteria are valuable in differ- entiating ILVT from wide QRS complex superior ventricular tachycardia. In addition, atrioventricular dissociation is frequently detected on the surface ECG of ILVT and represents the sole ECG finding to predict the presence of upper septal type ILVT.