不同浓度右美托咪定对离体兔心室肌电生理学特性的影响  

The effects of different concentrations of dexmedetomidine on ventricular electrophysiological properties in isolated rabbit hearts

作　　者：龙娟[1,2] 高鸿[1,2] 李惠[1,2] 张凯强[1,2] 刘艳秋[1,2] 钟毅[1,2] 

机构地区：[1]贵阳医学院麻醉学系 [2]贵阳医学院附属医院麻醉科,550004

出　　处：《临床麻醉学杂志》2015年第10期1000-1002,共3页Journal of Clinical Anesthesiology

基　　金：贵州省教育厅自然科学基金(黔科合LG字[2011]015号)

摘　　要：目的观察右美托咪定对离体兔心室肌单相动作电位的影响。方法成年家兔18只,体重2.0~2.5kg,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：正常对照组（C组）继续灌注37℃K-H液60min;低浓度右美托咪定组（L组）灌注含25ng/ml右美托咪定的K-H液60min;高浓度右美托咪定组（H组）灌注含50ng/ml右美托咪定的K-H液60min,每组6只。观察记录平衡灌注15min（T0）、继续灌注15min（T1）、30min（T2）、60min（T3）时的HR、左心室前壁三层心肌单相动作电位,计算单相动作电位复极50%和90%的时程（MAPD50和MAPD90）。记录早期后除极、延迟后除极及心律失常的发生情况。结果与T0时比较,T1~T3时H组HR明显减慢（P〈0.01）,MAPD50、MAPD90明显延长（P〈0.05）。C组和L组HR明显快于H组,MAPD50、MAPD90明显短于H组（P〈0.05）。结论 50ng/ml右美托咪定可延长MAPD50和MAPD90,其对心肌的电生理特性影响可能是减慢心率的机制。Objective To study the effects of dexmedetomidine on monophasic action potentials（MAPs）of myocardium in isolated rabbit hearts.Methods Eighteen adult rabbits,weighing of 2.0-2.5kg,prepared isolated heart perfusion model by Langendorff,the hearts were randomly divided into three groups after perfusion with K-H solution for 15minutes（n=6）：control group（group C）,continue perfusion with K-H solution for another 60min;Low concentrations of dexmedetomidine group（group L）,perfusion with 25ng/ml dexmedetomidine K-H solution for 60 min;High concentrations of dexmedetomidine group（group H）,perfusion with 50ng/ml dexmedetomidine K-H solution for 60 min.Record HR and three layer myocardial monophasic action potential（MAP）of left ventricular anterior wall after balanced infusion for 15min（T0）,continued perfusion for 15min（T1）,30min（T2）,60min（T3）,calculate the monophasic action potential schedule of repolarization at 50%（MAPD50）and 90%（MAPD90）.The occurrence of early phase after depolarization,delay phase after depolarization and arrhythmia were also observed.Results In group H,slower HR and prolonger MAPD50 as well as MAPD90 were found at T1-T3 than T0（P〈0.05）.Group H showed slower HR and longer MAPD50 as well as MAPD90 than groups C and L（P〈0.05）.Conclusion 50ng/ml dexmedetomidine can prolong MAPD50 and MAPD90,which may be the mechanism of slowing down heart rate.

关 键 词：右美托咪定 单相动作电位 电生理学技术 

分 类 号：R614[医药卫生—麻醉学]