兔LQT2模型时空复极异质性变化与室性心律失常发生的关系  

Relationship Between Spatiotemporal Heterogenity of Ventricular Repolarization and Ventricular Arrhythmia in Long QT Syndrome 2 Models.

作　　者：赵朝[1] 杨琳[1] 陈前[1] 刘丽平[1] 杨小梅[1] 

机构地区：[1]西安交通大学第一医院心内科,陕西西安710061

出　　处：《中国心脏起搏与心电生理杂志》2005年第5期373-375,共3页Chinese Journal of Cardiac Pacing and Electrophysiology

基　　金：国家自然科学基金资助课题(批准号:30100067)

摘　　要：为探讨心室跨壁复极离散度(TDR)和动作电位时程(APD)恢复性质的变化在LQT2室性心律失常发生中的作用,笔者采用冠状动脉灌注的兔左室肌楔形组织块制备LQT2模型。标本随机分四组:对照组(标准台氏液灌注);LQT2模型(简称模型)组(100μmol/Ld,l-sotalol灌流);模型+低钾(3mmol/L)组和模型+低钾+维拉帕米(2μmol/L)组。观察不同基础周长(BCL)刺激(500,1000和2000ms)条件下,四组标本APD90、TDR和APD恢复性质的变化与室性心律失常发生的关系。结果:①在不同BCL条件下,与对照组相比,模型组、模型+低钾组及模型+低钾+维拉帕米组的内外膜心肌细胞的APD90均增大,以内膜心肌细胞的APD90增大显著,导致TDR增加。②BCL为500和1000ms时,与对照组相比,模型组、模型+低钾组的APD恢复曲线斜率显著增加,而模型+低钾+维拉帕米组,差异无显著性。③在BCL为1000和2000ms时,给予S1S2程序刺激,模型+低钾组尖端扭转性室性心动过速发生率为5/7。结论:TDR增大和APD恢复性质的变化在室性心律失常的发生中均起着重要的作用。To investigate the role of transmural dispersion of repolarization（TDR） and cardiac restitution properties in arrhythimogeneity in LQT2, we observed the effects of d,1-sotalol, hypokalemia and calcium channel blocker（verapamil） on TDR and cardiac restitution properties at different basic cycle length（BCL） by using the arterially perfused rabbit left ventricular wedge preparation. Results：Perfused with d, 1-sotalol, d, 1-sotalol and hypokalemia, d, 1-sotalol, hypokalemia and verapamil, APDgo were prolonged in epicardium and endocardium, and specially in endocardium. So TDR was markedly increased. The maximum slopes of APD restitution curve was also increased at two different BCL in the presence of LQT2 model and hypokalemia, verapamil could markedly reduce APD and the maximum slopes of APD restitution curve. At BCL of 1 000 ms and 2 000 ms in the presence of d,1- solalol and hypokalemia, Tdp could be induced in 5 of 7 rabbits, whereas no Tdp occurred in the group after verapamil was added. Conclusion： Both TDR and APD restitution properties contribute to arrthymia in LQT2. [ Chinese Journal of Cardiac Pacing and Electrophysiology ,2005 ,19 （5） ：373 - 375 ]

关 键 词：电生理学 长QT综合征 恢复性质 跨壁复极离散度 维拉帕米 

分 类 号：R331.38[医药卫生—人体生理学] R541.7[医药卫生—基础医学]