瑞芬太尼对家兔离体心室肌动作电位时程及跨室壁复极不均一性的影响

Effects of Remifentanil on Monophasic Action Potential Duration and Transmural Dispersion of Repolarization of Myocardium in Isolated Rabbit Hearts

目的:观察不同浓度瑞芬太尼对兔心室肌单相动作电位时程及跨室壁复极不均一性的影响。方法:成年家兔24只,制备Langendorff离体心脏灌注模型,K-H液平衡灌注15 min后随机分为正常对照组(C组)、瑞芬太尼低浓度组(R1组)、中浓度组(R2组)及高浓度组(R3组),C组继续灌注37℃K-H液60 min,R1、R2、R3组分别灌注含12μg/L、25μg/L及50μg/L瑞芬太尼的K-H液60 min;记录平衡灌注15 min(T0)、继续灌注15 min(T1)、30 min(T2)、60 min(T3)时心率(HR)、左心室前壁3层心肌单相动作电位(MAP);计算单相动作电位复极90%的时程(MAPD90)和跨室壁复极离散度(TDR);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时点比较,R1、R2和R3组T1~T3时点HR减慢、MAPD90延长、TDR增大(P<0.05);T1~T3同一时点与C组比较,R1、R2和R3组HR减慢、MAPD90延长、TDR增大(P<0.05);与T1时点比较,R1、R2和R3组T3时点TDR增大明显(P<0.05)。结论:瑞芬太尼减慢HR、延长MAPD90、增大TDR,增加心室肌复极不均一性;随时间延长,瑞芬太尼增大TDR明显,室性心律失常风险可能增加。

Objective： To observe the effects of different concentrations of remifentanil on monophasic action potential duration and transmural dispersion of repolarization of 3 layer myocardium in isolated rabbit hearts. Methods： Adult rabbits （n = 24） were used to isolate hearts for preparing Langendorff perfusion model. The hearts were randomly divided into 4 groups after perfusion with K-H for 15 min ： the hearts in control group （ group C） continued the perfusion for 60 min ; the hearts in low concentra- tion of remifentanil group （R1 group） perfused with 12 0.g/L of remifentanil K-H solution for 60 rain; the hearts in medium concentration of remifentanil group （R2 group ） perfused with 25 p^g/L of remifentanil K-H solution for 60 min; the heart in high concentration of remifentanil group （R3 group） perfused with 50 p,g/L of remifentanil K-H solution for 60 min. The HR and 3 layers of myocardial monophasic action potential（MAP） in left ventricular anterior wall were recorded at 4 different time point, i.e. after balanced infusion for 15 min （ T0 ）, continued perfusion for 15 rain （ T1 ）, continued perfusion for 30 min （ T2 ） , continued perfusion for 60 rain （ T3 ）, respectively. The monophasic action potential duration of repolarization at 90% （ MAPDg0 ） and the transmural dispersion of repolarization （TDR） were calculated. The incidence of early after depolarization, delay after depolarization and ar- rhythmia were also observed. Results： Compared with To, in groups R1, R2 and R3, HR slowed, MAPD90 prolonged and TDR increased at T1 - T3 （ P 〈 0.05 ）. Compared with goup C, at the same time points, HR slowed, MAPD90 prolonged and TDR increased in group R1-3 （ P 〈 0.05 ）. Compared with T1 , at T3 TDR increased significantly in groups R1 , R2 and R3 （ P 〈 0. 05 ）. Conclusions： Remifentanil can slow HR, prolong MAPDgo, With the extension of time, remifentanil can ventricular arrhythmias. increase TDR and increase myocardial heterogeneity. significantly increase TDR, in turn increase the risk of