窦房结功能障碍时心房电活动的变化

Electrophysiologic characteristics of the atrium in rabbits with sinus node dysfunction

目的 :研究家兔窦房结功能障碍 (SND)时心房肌电生理变化。方法 :健康家兔 30只。用射频消融法消融窦房结区 ,建立SND模型。分别测定消融前及消融后 1、2、4、6h及 7d时心房有效不应期 (ERP)、期前收缩刺激时心房潜伏期 (S1 A1、S2 A2 )、S1、S2 刺激时心房反应时间 (A1、A2 )及心房肌波长指数 (WLI)。结果 :消融后 2、4、6h及 7d时心房ERP及WLI明显缩短 (P <0 .0 1) ,A1及A2 明显延长 (P<0 .0 1) ,以消融后 2h出现明显 ,6h已基本稳定。但消融后 1h与消融前比较 ,除WLI减少外 ,其他各项电生理指标差异无显著性意义。结论 :家兔SND时可导致心房ERP缩短 ,WLI降低 (心肌波长变小 ) ,传导缓慢及紊乱 。

Objectives: The aim of the study is to establish a rabbit sinus node dysfunction(SND) model for the study of electrophysiologic characteristics of the atrium and to investigate the electrophysiologic mechanisms of rabbites with SND to develop atrial fibrillation(Af) and atrial tachycarsia(AT). Methods: The model of SND was established in 30 rabbits with radiofrequenceablation method(ablated the sinus node region of the rabbits). At a drive cycl length of 200 ms, atrail effective refractory (ERP), the duration of atrial activation (A 1 and A 2) and atrial latency (S 1-A 1 and S 2-A 2) were measured.Wavelength index (WLI) was calculated(WLI=ERP/A 2). Results: We did not find significant statistical differences regarding S 1-A 1 and S 2-A 2 before and after SND. In contrast, A 1 ?A 2 Width were notable lenthening and WLI and ERP was significantly shortening in 2 h, 4 h, 6 h, 7 d after SND. Conclusion: In rabbits with SND, atrial ERP and WLI shortening , A 1?A 2 Width lengthening, at least in part, the tendency of rabbits with SND to develop Af?AT as a part of its natural history .Atrial electrophysiologic disturbances is an important mechanisms of rabbits with SND to develop Af and AT during natural course.