[Evaluation of the myocardial systolic function and ventricular remodeling of rats with experimental myocardial infarction by strain/strain rate imaging and MMP-9].

OBJECTIVE: To evaluate the myocardial systolic function and ventricular remodeling in heart failure rat induced by myocardial infarction (MI) with S/SRI and MMP-9. METHODS: A total of 70 male SD rats were randomly assigned to 4 groups: 4 weeks and 8 weeks MI (anterior descending branch of left coronary artery were ligated), sham operation (thoracotomy without ligation of coronary artery) and non-operated control group. The regional myocardial systolic function of rats was quantified with S/SRI. The myocardial MMP-9 expression was detected by Western blot. RESULTS: In the 4 weeks MI group, all segment's Ssys, SRsys, the strain of end-systole were reduced while PSI was increased compared to sham and non-operated group with the exception of the inferior wall. These changes were more significant in 8 weeks MI group compared to the 4 weeks MI group. In the 4 weeks MI group, the expression of MMP-9 was significantly upregulated than the sham operation group and this upregulation was more significant at 8 weeks post MI. CONCLUSIONS: S/SRI can quantitative evaluate the regional systolic function of heart failure rat induced by myocardial infarction. Progressive upregulation of myocardial MMP-9 expression paralleled the deterioration of regional systolic function in this heart failure rat model.