25例房性心动过速的电生理检查和射频消融结果

The results of electrophysiologic study and radiofrequency ablation in 25 patients with atrial tachycardia

目的探讨房性心动过速（房速）的发生机制和射频消融结果。方法对２５例房速患者进行心内电生理检查、药物试验和射频消融治疗。结果（１）２４例阵发性房速为折返机制，并且静脉注射三磷酸腺苷的终止率达８７％；而另１例慢性房速则是异常自律性增加。（２）２４例（９６％）房速消融成功。成功靶点的Ａ波较体表心电图Ｐ′波（Ａ－Ｐ′间期）提前３８±１１ｍｓ，明显长于非成功靶点（２６±７ｍｓ，Ｐ＜０．０５）。消融成功部位主要位于房内特殊的解剖区域。结论成年人阵发性房速的主要发病机制是折返性，并对三磷酸腺苷敏感。

Objective To investigate the mechanism of atrial tachycardia (AT) and the results of radiofrequency ablation. Methods Electrophysiologic study, drug test and radiofrequency ablation were performed in 25 patients with AT. Results It was showed that (1) in 24 patients, the suspected mechanism of paroxysmal AT was related to reentry, and 87% of these AT could be terminated by intravenous adenosine triphosphate (ATP); however the chronic AT in other 1 case was probably due to abnormal automaticity. (2) ATs were successfully ablated in 24 patients (96%). The intervals between the onset of local atrial wave and the P′ wave in surface electrocardiogram (AP′ interval) were 38±11ms at successful target sites which were mainly located in the special anatomic areas of atria, and were significantly longer than those at unsuccessful ablation sites (26±7ms, P<0.05). Conclusion It is suggested that the major mechanism of AT in adult patients is reentry, and these reentrant AT is adenosine sensitive. Radiofrequency ablation has shown to be an effective method to treat the AT.