右美托咪定对家兔离体心脏缺血-再灌注时心肌单相动作电位及跨室壁复极离散度的影响  

Effects of dexmedetomidine on the monophasic action potential duration and transmural dispersion of repolarization during ischemia-reperfusion in isolated rabbit hearts

作　　者：张凯强[1] 高鸿[2] 刘军[3] 刘艳秋[2] 龙娟[1] 李惠[1] 

机构地区：[1]贵州医科大学麻醉学院,贵阳市550004 [2]贵州医科大学附属医院麻醉科 [3]贵州医科大学附属人民医院心外科

出　　处：《临床麻醉学杂志》2016年第2期161-165,共5页Journal of Clinical Anesthesiology

基　　金：贵州省科技厅联合基金(黔科合LG字[2011]015号);贵阳市科技计划项目(筑科合同[20151001]社31号)

摘　　要：目的观察右美托咪定对家兔离体心脏缺血-再灌注心肌动作电位及跨室壁复极离散度的影响,探讨其对缺血-再灌注心肌电生理特性的作用。方法健康成年家兔18只,体重（2.0±0.5）kg,成功制备Langendorff离体心脏灌注模型,K-H液平衡灌注15min后,随机分为三组,每组6只：空白对照组（C组）：持续平衡灌注37℃K-H液150min;缺血-再灌注组（IR组）：K-H液继续灌注15min后停止,注射Thomas液（4℃,10 ml/kg）使心脏停搏60 min,心脏周围用低温（4℃）Thomas液保护,30min半量复灌Thomas液（4℃,5ml/kg）,60min时复灌K-H液;右美托咪定组（DEX组）：于K-H液及Thomas液中加入右美托咪定（25ng/ml）,余同IR组。记录平衡灌注15min（T0）、继续灌注15min/平衡30min（T1）、复灌30min/平衡120min（T2）、复灌60min/平衡150min（T3）的HR及三层心肌[内膜（Endo）、中膜（Mid）、外膜（Epi）]单相动作电位振幅（monophonic action potential amplitude,MAPA）,0相最大上升速率（Vmax）,90%单相动作电位时程（monophonic action potential duration,MAPD90）并计算跨室壁复极离散度（transmural dispersion of repolarization,TDR）,观察心脏复灌时心律失常、复跳时间,均不使用药物恢复心律。结果 DEX组心脏复跳时间（16.67±3.78）s明显短于IR组（46.33±7.29）s（P〈0.05）;心脏复跳时IR组有6例发生心律失常,2min内有2例恢复正常节律;DEX组有2例发生心律失常,2min内有1例恢复正常节律。与T0时比较,T2、T3时IR组,T1-T3时DEX组HR明显减慢（P〈0.05）;与T1时比较,T2、T3时DEX组HR明显减慢（P〈0.05）;与T2时和C组比较,T3时DEX组HR明显减慢（P〈0.05）;T1-T3时DEX组HR明显慢于IR组（P〈0.05）。与T0时比较,T1时DEX组Mid部位,T2、T3时DEX组Epi、Mid、Endo部位的MAPD90明显延长（P〈0.05）。与T1时比较,T3时DEX组Epi、Mid、Endo部位的MAPD90明显延长（P〈0.05）;T3时DEX组Mid部位的MAPD90明显长于C组（P〈0.0Objective To study the effects of dexmedetomidine on the monophasic action potential duration and the transmural dispersion of repolarization during ischemia-reperfusion of isolated rabbit hearts and thus explore its effect on myocardial ischemia-reperfusion electrophysiological characteristics.Methods Eighteen healthy adult rabbits,weighing（2.0±0.5）kg,were randomly divided into 3groups after successful preparation of Langendorff isolated heart perfusion model and 15 min perfusion and balance of K-H fluid.In the control group（group C）,37℃ K-H fluid was continuously perfused and balanced for 150 min.In the ischemia/reperfusion group（group IR）,K-H fluid was stopped after continuous perfusion and balance for 15 min and cardiac arrest was induced for 60 min with the injection of Thomas solution（4℃,10ml/kg）while the heart was protected by the low temperature Thomas solution（4 ℃）around it.Reperfusion of Thomas solution（4 ℃,5 ml/kg）was performed for 30 min and the heart was resuscitated by the perfusion of K-H fluid for 60 min.In dexmedetomidine group（group DEX）,dexmedetomidine（25ng/ml）was added in the K-H fluid and the Thomas solution.Other procedures were same as in group IR.Heart rate（HR）,monophasic action potential amplitude（MAPA）of the three layers of heart [endocardium（Endo）,myocardium（Mid）and epicardium（Epi）],0phase maximal increase rate（Vmax）,90% monophasic action potential duration（MAPD90）and transmural dispersion of repolarization（TDR）were recorded at the time of continuous balance perfusion 15min（T0）,continuous perfusion 15min/balance 30min（T1）,reperfusion 30min/balance 120min（T2）and reperfusion 60 min/balance 150 min（T3）.Cardiac arrhythmia and resuscitation time at cardiac reperfusion were observed,without using drugs to restore normal cardiac rhythm.Results In group DEX,cardiac resuscitation time was significantly shorter（16.67±3.78）s than that in group IR（46.33±7.29）s（P〈0.05）;At T2,in group IR,arrhythmi

关 键 词：右美托咪定 缺血-再灌注损伤 离体心脏 单相动作电位 跨室壁复极离散度 电生理学技术 

分 类 号：R614[医药卫生—麻醉学]