美西律对伊布利特心肌电生理特性的影响  

Effects of mexiletine on myocardial electrophysiological features of ibutilide

作　　者：王昊[1] 黄颖[1] 刘鹏[1] 崔海明[1] 廖德宁[1] 

机构地区：[1]第二军医大学长征医院心血管内科,上海200003

出　　处：《第三军医大学学报》2013年第22期2405-2408,共4页Journal of Third Military Medical University

摘　　要：目的观察美西律与伊布利特联用对心肌电生理特性的影响。方法制备犬左室楔形肌块模型,先后予正常台氏液、伊布利特台氏液、美西律-伊布利特台氏液灌流,并在灌流液更换后重复测量基础循环周长(basic cycle length,BCL)为500、667、1 000、2 000、4 000 ms时肌块外膜、中膜、内膜细胞的动作电位时程(action potential duration,APD)。结果伊布利特延长外膜、中膜、内膜APD(Ⅲ类效应),且伊布利特对APD的延长作用具有逆频率依赖性(reverse rate dependency,RRD);伊布利特对中膜APD的延长作用及其RRD最强[(10.8±2.1)ms vs(20.4±3.0)ms vs(17.3±3.1)ms;(15.8±4.0)ms vs(31.0±5.7)ms vs(21.5±3.4)ms;(18.4±3.5)ms vs(42.3±5.4)ms vs(24.0±3.5)ms;(23.0±3.6)ms vs(53.8±5.4)ms vs(31.3±3.6)ms;(25.6±4.2)ms vs(55.9±4.4)ms vs(34.8±3.2)ms,P<0.01];伊布利特对跨室壁复极离散度(transmural dispersion of repolarization,TDR)的增大作用也具有RRD。美西律可抑制伊布利特对各层心肌,特别是对中膜的Ⅲ类效应及其RRD,减小TDR。结论美西律与伊布利特联用可有效抑制伊布利特Ⅲ类作用的RRD,提高伊布利特的使用安全性。Objective To investigate the effect of mexiletine combined with ibutilide on electrophysiological characteristics of myocardia. Methods Arterially perfused canine left ventricular wedge preparations were isolated from mongrel dogs and perfused with normal Tyrodes’ solution, ibutilide Tyrodes’ solution, and mexiletine-ibutilide Tyrodes’ solution sequentially. Action potential duration （APD） of epicardium, mid-myocardium, and endomyocardium was measured under basic cycle length （BCL） of 500, 667, 1 000, 2 000, and 4 000 ms repeatedly after the perfusate was changed. Results Ibutilide prolonged APD of all layers of myocardium （class Ⅲ effect） in a manner of reverse rate dependency （RRD）, with the most prominent effect on mid-myocardium （10.8±2.1 vs 20.4±3.0 vs 17.3±3.1 ms; 15.8±4.0 vs 31.0±5.7 vs 21.5±3.4; 18.4±3.5 vs 42.3±5.4 vs 24.0±3.5 ms; 23.0±3.6 vs 53.8±5.4 vs 31.3±3.6 ms; 25.6±4.2 vs 55.9±4.4 vs 34.8±3.2 ms, P〈0.01）. Ibutilide also prolonged transmural dispersion of repolarization （TDR） in a manner of RRD. Mexiletine suppressed class Ⅲ effect of ibutilide and its RRD on all layers of myocardium, especially on mid-myocardium and reduced TDR. Conclusion Mexiletine combined with ibutilide can suppress class Ⅲ effect of ibutilide and its RRD, and enhance the safety of ibutilide.

关 键 词：美西律 伊布利特 逆频率依赖性 跨室壁复极离散 

分 类 号：R322.11[医药卫生—人体解剖和组织胚胎学] R337.5[医药卫生—基础医学]