The causes of acute myocardial infarction are as follows: 1. rupture or erosion of plaque of coronary atherosclerosis, formation of thrombus, resulting in luminal narrowing or complete obstruction, significant and lasting ischemia and hypoxia of myocardium, or even necrosis, which is the most common clinical cause of morbidity; 2. coronary embolism, congenital malformation of coronary arteries; 3. coronary artery spasm: high-intensity stressful environment or severe climate and other triggering factors, resulting in severe ischemia and hypoxia of coronary arteries and blockage of blood flow, leading to morbidity.