芪苈强心对心梗后兔心功能及心肌电生理的影响

Effect of Qiliqiangxin on cardiac function and electrophysiology in rabbits with myocardial infarction

目的观察中成药芪苈强心对新西兰大耳白兔心肌梗死模型的心功能及心脏电生理特性的影响,以探讨其治疗心梗后心衰及心律失常的机制。方法将24只新西兰大耳兔随机分为假手术组、心梗对照组、心梗芪苈强心组,每组8只。以人工结扎兔心脏冠脉左回旋支建立心梗模型,心梗芪苈强心组于建立心梗模型的第1天开始灌胃给予芪苈强心粉末[0.3 g/(kg·d)]。4周后,行超声心动图检查及在体电生理研究。结果 1与假手术组比较,心梗对照组左心室收缩末期内径(LVESD)、左心室舒张末期内径(LVEDD)、左心室后壁厚度(LVPWD)、舒张末期室间隔厚度(IVSD)增大(P<0.05),左心室射血分数(LVEF)、左心室短轴缩短分数(LVFS)减小(P<0.05);与心梗对照组比较,心梗芪苈强心组LVESD、LVEDD、LVPWD、IVSD减小(P<0.05),LVEF、LVFS增大(P<0.05)。2与假手术组比较,心梗对照组左室梗死周边区和正常区动作电位时程(APD)幅值明显降低(P<0.05);周边区动作电位时限复极90%时间(MAPD90)明显缩短(P<0.05),有效不应期(ERP)明显延长(P<0.05);正常区MAPD90、ERP明显延长(P<0.05)。与心梗对照组比较,心梗芪苈强心组左室梗死周边区和正常区APD幅值明显升高(P<0.05),周边区MAPD90明显延长(P<0.05),正常区MAPD90明显缩短(P<0.05)。结论芪苈强心胶囊可通过改善因心肌细胞缺血引起的心功能减退和抑制心室重构、延长心肌细胞梗死周边区心肌异常缩短的APD、缩短远离梗死区域心肌异常延长的APD、缩短心肌细胞的ERP来治疗心肌梗死后室性心律失常。

Objective To evaluate the effects of traditional Chinese medicine Qiliqiangxin（QLQX） on the cardiac function and the cardiac electrophysiological characteristics after myocardial infarction（MI） in New Zealand white rabbits,so as to explore the mechanism of QLQX against heart failure and antiarrhythmic after myocardial infarction. Methods Twenty four rabbits were randomly divided into three groups： sham-operated group（n = 8）, MI group（n = 8） and QLQX group（n = 8）. Rabbits were adapted to left sternal thoracotomy and hearts were exposed. QLQX group was given QLQX [0.3 g/（kg·d）] by gastric gavage one day after the establishment of MI model. The ultrasonic echocardiography was examined and electrophysiology in vivo was studied. Results 1Compared with sham operation group, left ventricular end-systolic dimensions（LVESD）, left ventricular end-diastolic dimensions（LVEDD）, left ventricular posterior wall depth（LVPWD） and IVSD in MI group increased（P〈0.05）, LVEF, LVFS decreased（P〈0.05）; compared with MI group, LVESD, LVEDD, LVPWD, IVSD in QLQX group decreased（P〈0.05）, LVFS and LVEF increased（P〈0.05）.2Compared with the sham operation group, the action potential duration（APD） amplitude of left ventricular infarction surrounding region and normal region in MI group decreased significantly（P〈0.05）; the MAPD90 of surrounding region was shortened obviously（P〈0.05）, ERP was prolonged significantly（P〈0.05）; the MAPD90, ERP of normal region was prolonged significantly（P〈0.05）; compared with MI group, the APD amplitude of left ventricular infarction surrounding region and normal region in QLQX group was significantly increased（P〈0.05）, the MAPD90 of peripheral region was prolonged significantly（P〈0.05）, the MAPD90 of normal region was shortened obviously（P〈0.05）. Conclusion QLQX Capsule can treat ventricular arrhythmias after MI through improving heart failure caused by myocardial ischemia, inhibiting ventricular remodeling, prolonging abnormal shortened APD of ventricular infarction surrounding region, shortening abnormal prolonged APD away from the infarction area and ERP of myocardial cells.