硫酸镁对家兔在体心脏跨室壁心肌复极不均一性的影响  

Effect of magnesium sulfate on myocardium repolarization heterogeneity across the left ventricular wall in vivo

作　　者：张存泰[1] 李运田[1] 陆再英 

机构地区：[1]华中科技大学同济医学院附属同济医院心内科,武汉430030

出　　处：《中华心血管病杂志》2001年第11期680-682,共3页Chinese Journal of Cardiology

基　　金：卫生部科研基金资助项目 (98 2 0 95 )

摘　　要：目的　观察静脉注射索他洛尔后 ,硫酸镁对家兔跨室壁心肌复极不均一性的影响 ,探讨其治疗室性心律失常的机制。方法　采用单相动作电位 (monophasicactionpotential,MAP)记录技术 ,同步记录 12只开胸兔左室心外膜心肌、中层心肌和心内膜心肌的MAP ,在静脉注射索他洛尔基础上 ,静脉滴注硫酸镁后观察其对心肌复极不均一性的影响。结果　 (1)索他洛尔剂量依赖性地显著延长中层心肌的MAP复极 10 0 %时程 ,增加跨室壁复极离散度 (transmuraldispersionofrepolarization ,TDR) ;静脉滴注硫酸镁后TDR明显减少。 (2 )索他洛尔剂量依赖性地诱发早期后除极 (earlyafterdepolarization ,EAD)和尖端扭转型室性心动过速 (torsadedepointes,TdP)的发生率 ;硫酸镁抑制索他洛尔诱导的EAD和TdP。结论　硫酸镁逆转索他洛尔所致的TDR增加 ,抑制索他洛尔诱导产生EAD 。Objective To observe the effect of magnesium sulfate on myocardium repolarization heterogeneity across the left ventricular wall after intravenous administration of sotalol and explore the mechanism of magnesium sulfate treatment on arrhythmias Methods With the monophasic action potential (MAP) recording technique, MAPs of epicardium (Epi), mid myocardium (Mid) and endocardium (Endo) were recorded by specially designed plunge needle electrodes inserted into the left ventricular myocardium in 12 thoracotomized rabbits After intravenous injection of sotalol, the effect of magnesium sulfate on myocardium repolarization heterogeneity across the left ventricular wall were investigated in vivo Results (1) Sotalol increased transmural dispersion of repolarization (TDR)among three myocardial layers in a dose dependent manner, and magnesium sulfate decreased the TDR (2) Sotalol increased the incidence of early afterdepolarization (EAD) and torsade de pointes (TdP) dose dependently; magnesium sulfate inhibited EAD and TdP induced by sotalol Conclusion The fact that magnesium sulfate decreases TDR and suppreses EAD induced by sotalol may be associated with its therapeutic mechanism for arrhythmias

关 键 词：硫酸镁 索他洛尔 动作电位 心肌复极不均一性 电生理学 心动过速 

分 类 号：R540.5[医药卫生—心血管疾病]