绵羊心肌梗塞后心脏重构的研究

Objective Myocardial infarction (MI) continues to be a major health care problem. Left ventriclular (LV) remodeling after MI is associated with disability and death. The present study aims to examine the strains in the remodeling myocardium in a large animal model. Methods Ten male Dorsett hybrid sheep bred for laboratory use were randomly divided to two groups: Non-MI(N=5) and MI(N=5). MI of 25% LV mass was created in MI group by ligation of coronary arterys. Echocardiograms and hemodynamic data were collected. The post-MI LV regional movement and deformation were monitored with sonomicrometry and quantified using areal end-systolic strain and remodeling strain. Results Both the LVESV and the LVEDV increased significantly, while the EF decreased over 10 weeks after MI. An increase in the length of wall motion abnormality was observed. Likewise, the ratio of wall motion abnormality to endocardial circumference significantly increased. There is no statistically significant change in heart rate, mean arterial pressure, and cardiac output during the whole course of the study. The end-systolic strains of the infarct and the adjacent regions decreased significantly after MI, while the remodeling strains of the infarct and the adjacent regions increased significantly after MI. Conclusions The sheep MI model created by ligation of coronary arterys is a representative cardiac remodeling model. The sonomicrometry array showed that the process of remodeling is inhomogeneous and the end-systolic and remodeling strain are region-specific.