Clinical studies have shown that almost all myocardial infarctions, especially in elderly patients, are mainly caused by coronary atherosclerosis, and occasionally by coronary embolism, inflammation, or congenital malformations. Occlusive thrombi can be found in the coronary arteries in 85%–95% of autopsied cases of acute myocardial infarction. On the basis of coronary atherosclerosis, once hemorrhage occurs within or under the atherosclerotic plaque, or persistent vasospasm and thrombosis develop, the coronary artery becomes completely occluded, resulting in myocardial infarction. Although the acute myocardial infarction model induced by open‑chest ligation of the left anterior descending coronary artery differs somewhat from the clinical pathogenesis, and the open‑chest procedure itself causes a series of pathophysiological changes in animals, the myocardial pathology and ECG changes are similar to those observed clinically.

- **Animals**: SD rats, male or female, 6–8 weeks old, 180–220 g
- **Model establishment**: Myocardial infarction model was established by ligation of the left anterior descending coronary artery.
- **Evaluation indexes**: Electrocardiogram (ECG), TTC staining, H&E staining, Sirius Red staining

Electrocardiogram (ECG)

Cardiac TTC staining

Myocardial tissue HE staining

Myocardial tissue Sirius Red staining