【摘要】 目的观察不同浓度瑞芬太尼对心室肌单相动作电位的影响。方法制备Langendorff离体兔心脏模型24个,K-H液灌注15 min后,随机分为4组,每组均6只,对照组继续灌注K-H液60 min;实验组分别灌注含12,25,50ng·m L-1瑞芬太尼的K-H液60 min。平衡灌注15 min(T0)、继续灌注15,30,60 min(T1~T3)时,记录心率、0相最大上升速率(Vmax)、单相动作电位振幅(MAPA)及单相动作电位复极50%,90%的时程(MAPD50,MAPD90)。结果与T0和对照组比较,3个浓度瑞芬太尼组在T1~T3时点,心率明显减慢,MAPD50、MAPD90明显延长(P<0.05)。与T0和对照组及低浓度组比较,中、高2个浓度实验组在T1~T3时,Vmax明显减慢,同时MAPA明显降低(P<0.05)。结论瑞芬太尼无浓度依赖性地减慢心率、延长动作电位时程;中、高2个浓度瑞芬太尼影响除极,可能是其引起心脏传导阻滞的机制之一。更多还原

【Abstract】 Objective To study the effects of different concentrations of remifentanil on monophasic action potentials( MAP) of myocardium in isolated rabbit hearts. Methods Twenty-four prepared isolated heart perfusion model by Langendorff. The hearts were randomly divided into four groups after perfusion with K-H 15 minutes( n = 6) : it continue perfusion 60 min in control group. The heart model in test groups were treated perfused with 12,25 and 50 ng·m L-1of remifentanil with K-H solution 60 min. The heart rate( HR),the 0 phase of the maximum rate of rise( Vmax),the monophasic action potential amplitude( MAPA) and monophasic action potential duration of repolarization at 50% and 90%( MAPD50,MAPD90) were recorded after balanced infusion 15 min( T0),continued perfusion 15,30,60 min( T1-T3). Results The HR,prolonger MAPD50 and MAPD90at T1-T3 in test groups were slower than T0 and control group( P < 0. 05). Both the Vmaxand MAPA at T1-T3 in the middle and high concentrations groups was slower was lower than T0,control group and low concentration of test group( P < 0. 05). Conclusion Remifentanil slows the heart rate and prolong the action potential duration when the process was not concentration dependent. Effect of middle and high concentrations of remifentanil on depolarization may be one of the mechanisms that cause heart block.更多还原