心肌梗死大鼠左心室收缩与舒张功能的改变及其影响因素

目的 探讨心肌梗死大鼠左心室收缩和舒张功能的改变、以及心室重构对心室舒缩功能的影响.材料和方法结扎Wistar大鼠左冠状动脉、制成心肌梗死模型,6周后测定左室心肌力学指标,心肌胶原含量、血浆及心肌的血管紧张素Ⅱ(Aug Ⅱ)浓度.结果 心肌梗死组与对照组比较,LVPSP、+dp/dt_(max)、dp/dt_(max)绝对值及V_(max)明显降低(P<0.01),LVEDP增加(P<0.01),T值延长(P<0.01),MAP无差异.心肌梗死组与对照组比较、心肌羟脯氨酸和心肌胶原含量明显增高(P均0.01),心肌AngⅡ含量明显升高(P<0.01)、血浆AngⅡ浓度无显著差异.结论 心肌梗死后左室收缩与舒张　功能明显降低,同时出现心肌细胞的肥大和纤维细胞的增生以及间质纤维化、后者可进一步导致和加重心脏泵血功能的异常.

Changes and Relation of Ventricular Mechanical Function and Ventricular Remodeling in Myocardial Infracted Rats

Objective To evaluate changes of left ventricular mechanical function in myocardial infarction (MI) rats. Methods 6 weeks after coronary artery ligation,multiple parameters of left ventricular (LV) hemodynamics, cardiac collagen content,plasma and cardiac angiotensin Ⅱ (Ang Ⅱ ) concentration in rats were measured. Result In MI group of rats compared with those of control group, LV peak systolic pressure, the maximum rate of rise and decline of LV pressure (±dp/dtmax), the maximal velocity of shortning of the contractile element (Vmax) were significantly decreased, beart rate and LV end diastolic pressure were significantly increased, T value were significantly lengthened (all P<0. 01), and mean artery pressure was not different (P>0. 05); cardiac Ang Ⅱ and cardiac collagen content were increased (P<0. 01), plasma Ang n was not different (P>0. 05). The ratio of cardiac weight to body weight was higher in MI group compared with controlcgroup- (P<0. 01). Conclusion Acute myocardial infarction may damage left ventricutar systolic and diastolic function, and may produce ventricular remodeling which might make cardiac function deterioration.