Acute myocardial infarction (AMI) refers to acute necrosis of part of the myocardium due to persistent and severe myocardial ischemia. Clinically, it is often manifested as chest pain, acute circulatory dysfunction, and a series of characteristic electrocardiogram changes reflecting myocardial damage, ischemia, and necrosis. Clinical manifestations often include persistent severe pain behind the sternum, acute circulatory dysfunction, arrhythmia, heart failure, fever, elevated white blood cell count and serum myocardial injury marker enzymes, and progressive electrocardiogram changes of acute myocardial damage and necrosis. According to the scope of infarction, myocardial infarction can be divided into two categories: transmural myocardial infarction and subendocardial myocardial infarction. According to the development process of the lesion, myocardial infarction can be divided into acute myocardial infarction and old myocardial infarction.