心房颤动电重构的实验研究

Experimental study on electrical remodeling of atrial fibrillation

目的 :研究犬心房颤动 (Af)模型心房有效不应期 (ERP)的变化 ,验证Af电重构这一假说的正确性。方法 :采用快速心房起搏的方法建立犬的Af模型 (起搏组 ,n =13) ,用程序刺激测量心房的ERP ;观察P波时限和PA间期的变化 ,并与假手术组 (对照组 ,n =7)作比较。结果 :持续快速起搏 9～ 10周后 ,心房ERP明显缩短 ,当S1S1为 30 0ms时 ,对照组与起搏组分别为 (15 0± 2 1)ms与 (115± 2 3)ms(P<0 .0 1) ;S1S1为 4 0 0ms时分别为(15 4± 2 4 )ms与 (10 5± 2 7)ms(P <0 .0 1)。起搏组P波时限和PA间期明显长于对照组。结论 :持续心房快速刺激可使ERP明显缩短 ,使心房发生电重构。

Objective:To use the model of sustained AF to explore the electrophysiological changes and to test the hypothesis electrical remodeling. Methods:The model of sustained AF was established by chronic rapid atrial pacing in 10 dogs. 7 sham operated dogs were served as control. ERP by programmed electrical stimulation was measured in both atria. P wave duration and PA interval were also measured.Results:A significant reduction in atrial ERP was documented at cycle length drives of 400 and 300 ms (154±24) ms versus (105±27) ms and (150±21) ms versus (115±23) ms, respectively, P< 0.01 ) in the control and paced groups. Significant increases in P wave duration and PA interval were observed in the paced groups.Conclusion:Atrial ERP is significantly shortened with rapid atrial pacing, indicating atrial electrical remodeling. Atrial electrical remodeling can contribute to presence and persistence of AF.