灯盏花素对家兔肥厚心肌室性心律失常的影响

Effect of breviscapine tablets on ventricular arrhythmias in hypertrophic myocardium of rabbit heart

目的观察口服灯盏花素对家兔肥厚心肌室性心律失常的影响,探讨灯盏花素抗心律失常的作用机制。方法 30只家兔随机分为假手术组、心肌肥厚组和灯盏花素组,每组10只。假手术组开腹但不行腹主动脉缩窄术;心肌肥厚组和灯盏花素组采用腹主动脉缩窄术制备家兔心肌肥厚模型;灯盏花素组自手术后第2天开始喂服灯盏花素,每只每日1片,喂养8周。制备兔左心室楔形心肌块,利用浮置玻璃微电极法同步记录楔形心肌块内、外膜心肌细胞跨膜动作电位和跨壁心电图;测心脏质量(HW)、体质量(BW)和左心室游离壁厚度(LVT)。观察各组QT间期和内、外膜心肌细胞跨膜动作电位以及跨室壁复极离散度(TDR),程序电刺激诱发室性心律失常,记录跨膜动作电位复极90%的时程(APD90),早期后除极(EAD)和尖端扭转性室性心动过速(Tdp)的发生率。结果心肌肥厚组与灯盏花素组HW、HW/BW及LVT值与假手术组相比均明显升高(P<0.05);灯盏花素组HW、HW/BW及LVT值与心肌肥厚组相比均明显减小(P<0.05)。心肌肥厚组与灯盏花素组QT间期及内、外膜心肌APD90较假手术组明显延长(P<0.05);灯盏花素组QT间期及内、外膜心肌APD90与心肌肥厚组相比明显缩短(P<0.05)。假手术组、心肌肥厚组和灯盏花素组TDR分别为(55±17)、(99±12)和(68±11)ms,3组间比较差别有统计学意义(P<0.05)。灯盏花素组EAD和Tdp的发生率明显低于心肌肥厚组(P<0.05)。结论肥厚心肌TDR增大,心律失常的发生率显著升高。灯盏花素可减少TDR,明显降低EAD和Tdp的发生率。

Objective To observe the effect of breviscapine tablets on ventricular arrhythmias in hypertrophic rabbit hearts and study the antiarrhythmia mechanism of breviscapine.Methods Thirty rabbits were randomly divided into sham-operation group,cardiac hypertrophy group and breviscapine group,ten rabbits in each group.Rabbit model of cardiac hypertrophy were made by abdominal aorta constriction in cardiac hypertrophy group and breviscapine group,and the abdominal aorta was only exposed without constrition in sham-operation group.Breviscapine tablet was fed from the second day of constrition in breviscapine group,one tablet per day,all rabbits were fed for eight weeks.By using arterially perfused rabbit ventricular wedge preparations,the transmural electrocardiogram.The levels of heart weight（HW）,body weight（BW） and left ventricle thickness（LVT） were measured.QT interval and transmembrane action potentials from epicardium and endocardium were simultaneously recorded,the transmural repolarization dispersion（TDR）and 90% action potential duration（APD90） and the induced incidence of early afterdepolarization（EAD） and torsades de pointes（Tdp） were observed.Results The levels of HW,HW/BW,LVT,QT interval and APD90 from epicardium and endocardium in cardiac hypertrophy group and breviscapine group were higher than those in sham-operation group（P〈0.05）,but the levels of those in breviscapine group were reducer than those in cardiac hypertrophy group（P〈0.05）.The levels of TDR were（55±17）,（99±12） and（68±11） ms,there was statistically significant in difference in three groups（P〈0.05）.The incidences of EAD and Tdp in breviscapine group were lower than those in cardiac hypertrophy group（P〈0.05）.Conclusion TDR and the incidence of arrhythmias were increased in hypertrophy heart.Breviscapine could diminished TDR and the incidences of EAD and Tdp.