三维电解剖标测左心室特发性室性心动过速缓慢传导区

Value of identifying the slow conduction zone of idiopathic left ventricular tachycardia byelectroanatomic mapping

目的通过三维电解剖技术标测左心室特发性室性心动过速（idiopathic left ventricular tachycardia，ILVT）的缓慢传导区（slow conduction zone，SCZ）。方法使用三维电解剖标测技术对12例ILVT患者进行标测，构建左心室解剖模型，在窦性心律和室性心动过速下对左后分支电位（posterior fascicular potential，PP）及舒张期电位（diastolic potential，DP）进行标测，研究分析SCZ的电生理特性及解剖分布特征。结果9例患者在窦性心律和室性心动过速下进行三维标测，3例患者只在室性心动过速下进行标测。能够记录到DP的SCZ位于左心室后间隔基底部，长度约（25．1±2．2）mm，传导速度为（0．08±0．01）m／s，且在窦性心律下和室性心动过速时差异无统计学意义（P〉0．05）。左后分支PP区位于左后间隔部。其中9例患者在窦律和室速时均标测到DP与PP交汇区，此交汇区在窦性心律下和室性心动过速时位置相同，且所有患者在此交汇区消融放电均能终止室性心动过速。结论SCZ与左后分支的交汇区是消融ILVT的关键区域，可通过对该区域的标测来指导ILVT的消融。

Objective To explore the value of identifying slow conduction zone（SCZ） of idiopathic left ventricular tachycardia（ILVT） by electroanatomic mapping. Methods Twelve patients with ILVT were mapped by a 3-dimensional electroanatomic （EA） mapping system. Left posterior fascicular potential （PP） and the SCZ with diastolic potential （DP） in LV during sinus rhythm （SR） and ventricular tachycardia （VT） were mapped after a three-dimensional endocardial geometry of the left ventricular was established. Then we investigated the electrophysiological and anatomic characteristics of SCZ. Results EA mapping was successfully performed in 9 patients during SR and VT, and in 3 patients during VT. The SCZ with DP was located at the inferoposterior septum, and the length of the SCZ was （25. 1 ± 2. 2） mm with a conduction velocity of （0. 08 ± 0.01 ） m/s. There was no difference in these parameters between patients during SR and VT （ P 〉 0. 05 ）. There was one area with PP located at the posterior septum. The areas with both DP and PP were found in 9 patients during SR and VT. In addition, this area was coincided with such area during VT during SR and radiofrequency ablation targeting the site within the area abolished VT in all patients. Conclusions The ILVT substrate within the junction area of the SCZ and the posterior fascicular can be identified by EA mapping and used to guide the ablation of ILVT.