心房起搏对心房电生理学特性的影响及治疗房颤的作用机制研究

目的：分析心房起搏对心房电生理学特性的影响，探讨其治疗房颤的可能作用机制。方法：39例不伴器质性心脏病的阵发性室上性心动过速病人，于射频消融成功后给予心房起搏(RAA起搏，DCS起搏和双心房起搏)，分别测定不同起搏状况下RAA处的心房有效不应期(ERP)和心房传导时间(RAA-His,RAA-DCS)。结果：DCS和双心房起搏后，RAA起搏相比较，RAA处的心房传导时间明显缩短，ERP显延长(P＜0．01)；且DCS起搏与双心房起搏相比，前对心房传导时间和ER的影响更为显。14例阵发性房颤病人(包括既往有阵发性房颤病史和起搏过程中诱发房颤的思)与25例非阵发性房颤病人相比，前RAA起搏时的心房传导时间较长，ERP较短(P＜0.05)。结论：DCS起搏和双心房起搏可改变心房的电生理学特性，缩短心房传导时间，延长ERP，其中尤以DCS起搏的改变最为显。心房起搏对心房电生理学特性的改变可能是其治疗和预防房颤的主要机制。

Study on the Effects of Atrial Electrophysiologic Properties and the Mechanism in Treatment of Atrial Fibrillation with Atrial Pacing

Objective: This study was designed to analyze the effects on the atrial electrophysiologic properries and the mecha-nism in treatment of atrial fibrillation with atrial pacing. Methods: 39 patients without structural heart disease were enrolled to receive different modes of atrial pacing (RAA, DCS, biatrial), Meanwhile, the atrial conduction times and the atrial effective refractory period (ERP) at RAA were determined. Results: Both DCS and biatrial pacing were able to reduce the atrial conduction times and the atrial ERPat RAA significantly(P < 0.01),the difference of effects between DCS and biatrial pacing was also significant (P < 0.05) .So as to 14 patients with PAF(incIuding those had history of PAF and those with induced PAF during pacing), atrial conduction times were shorter and ERP longer at RAA than 35 non - PAF patients during RAA pacing(P < 0.01) .Conclusion: Both DCS and biatrial pacing can change the atrial electrophysiologic properties - reducing the atrial conduction time and prolonging the atrial ERP, but the effects of DCS pacing is prior to that of biatrial pacing. These changes may be the major mechanism in treatment of atrial fibrillation proba-bly.