应用非接触球囊导管标测系统指导心动过速的心内膜标测与消融

目的观察非接触球囊导管标测系统指导难治性室性心动过速的标测与射频消融的有效性和优越性。方法5例患者均为男性，平均年龄33.2岁。经股静脉或股动脉置入64极球囊电极和射频消融导管至同一心室，计算机标测系统首先构建心腔的几何构型，然后建立心动过速的腔内等电势图，分析心动过速的最早起源点及折返激动的关键峡部，最终利用计算机导航系统指导消融导管至拟定靶点处进行环状或线形消融。结果5例患者共诱发出6种心动过速，心动过速平均周期为（336.6±42.7）ms。2例特发性左室室性心动过速及1例隐匿性束室纤维患者均消融成功。1例扩张型心肌病患者共有两种心动过速，一种起源于右室流出道，另一种起源于左室间隔部，前者消融成功，后者因导管操作致心动过速持续发作伴血流动力学不稳定而终止手术。1例致心律失常性右室心肌病患者于最早激动点处做环状消融，未获成功。5例患者术中和术后均无并发症发生。随访4个月，所有消融成功患者均未再有心动过速发作。结论非接触性球囊导管标测系统指导心律失常的心内膜标测与消融是安全、有效的，与常规的标测和消融方法比较，该系统有一定的优越性，尤其适用于复杂病例、血流动力学不稳定和非持续性室性心律失常的标测及指导射频消融。

Endocardial mapping and ablation of tachycardia using a noncontact balloon catheter mapping system

Objective　To describe a new computerized mapping system with a noncontact balloon catheter and to assess the clinical utility and advantage of this system for mapping and ablation of refractory tachycardias. Methods　Five male patients with a mean age of 33.2 years underwent electrophysiological study and radiofrequency ablation using the noncontact, computerized mapping system. A 9F 64 electrode balloon catheter and a conventional 7F ablation catheter were positioned via a femoral artery or vein into the same ventricular chamber. By use of the recorded location of the ablation catheter tip, ventricular three-dimensional geometry was established. Using a boundary element inverse solution, 3360 virtual endocardial electrograms were computerized and used to derive isopotential maps. Radiofrequency catheter ablation with linear or circular lesion was performed at the earliest activation sites or the isthmus guided by the locator system. Results　Six kinds of tachycardia, 5 of ventricular and 1 of concealed fasciculoventricular fiber mediated tachycardia ,were induced by programmed stimulation in 5 cases and the mean cycle length of tachytcardia was (336.6±42.7)ms. Among the 6 kinds of tachycardia, radiofrequency ablation guided by the locator system was successful in 4 kinds. There were no complications during and after the procedure. In 4 months follow-up no relapse occurred in those cured cases either. Conclusions　The noncontact mapping system described in this study computes accurate isopotential maps that are used as a useful guide for catheter ablation of tachycardia,especially for hemodynamically unstable and nonsustained ventricular tachycardia. It is also suitable for understanding the electrophysiologic mechanism of rare kinds of tachycardia.