窦性心律下非接触式标测指导线性消融治疗特发性左心室室性心动过速

Noncontact mapping and linear ablation of left posterior fascicle during sinus rhythm in the treatment of idiopathic left ventricular tachycardia

目的 大多数特发性左心室室性心动过速(ILVT)是起源于左后分支(LPF)浦肯野纤维网的折返性心动过速,因而利用非接触式标测系统在窦性心律下标测LPF并经其导航系统指导线性消融治疗ILVT是可行的,现介绍此方法的安全性和有效性。方法 6例患者,1例既往接受3次射频导管消融术,临床呈无休止发作;1例为常规消融术后1个月复发;4例为常规首次接受射频导管消融术患者。其中男性5例,女性1例,平均年龄15～58(34.00±16.26)岁。常规电生理检查明确ILVT诊断后,将球囊电极导管经股动脉逆行送入至左心室心尖部,构建几何构形后建立窦性心律的等电位图。结果 窦性冲动沿希氏束向下传导,在间隔中部不到心尖处激动局部间隔心肌并很快激动整个左心室。局部虚拟电图显示,在间隔部激动的每个QRS波前均有高频、低幅的电位,该电位与QRS波之间的距离随激动的推移而逐渐缩短;心室激动爆发点处的局部电图呈QS型。在心室激动爆发点上方1 cm处于LPF区域作垂直于LPF激动方向的线性消融,消融后所有患者均出现不同程度的左后分支阻滞图形,线性消融的平均放电次数为4～8(5.66±1.50)次,消融完毕后心动过速均不能诱发。平均随访7～13(10.00±2.76)个月,所有患者均无心动过速复发。结论

Objectives To evaluate the safety and efficacy of noncontact mapping and linear ablation of left posterior fascicle (LPF) during sinus rhythm in the treatment of idiopathic left ventricular tachycardia (ILVT). Methods There were totaly six patients [5 male, 1 female, mean age (34.00+16.26) years] included in the study, one with incessant tachycardia who failed the conventional radiofrequency ablation procedure 3 times, one with noninducible tachycardia after the multielectrode array (MEA) placement, the rest four patients were routine ILVT cases. After the diagnosis of ILVT was made by electrophysiological study, MEA was advanced retrogradely and deployed in the left ventricle. Left ventricular endocardial contour was then made and isopotential maps of sinus rhythm was established. Results Sinus activation began at His area and propagated down the left septum, broke out radially at the mid-level of the left septum. Local virtual electrograms showed a short, sharp, high-frequency and low-amplitude potential preceding the ventricular potential in the area of left bundle and Purkinje conduction sytem, and QS morphology of ventricular activation in the break-out area. Linear ablation lesions perpendicular to LPF propagation direction was done 1cm above the break-out point. The mean times of radiofrequency deliveries was (5.66±1.50). Left posterior fascicular block of different degree was recorded by body surface ECG after linear ablation. No tachycardia could be induced after the procedure and no tachycardia recurred after a mean follow-up of (10.00±2.76) months. Conclusions Mapping and linear ablation of LPF during sinus rhythm guided by noncontact mapping system in the treatment of ILVT is not only safe and effective, but also simple and time saving, especially for those tough cases, recurred cases and uneasily inducible cases.