Acute myocardial infarction is a disease in which a sudden blockage of the coronary artery leads to myocardial cell necrosis. It often presents with pain in the precordial region for more than 30 minutes, which may radiate to other parts of the heart, and the attack is often accompanied by profuse sweating and a sense of near death. It can be diagnosed by electrocardiogram, but if the electrocardiogram is not abnormal, the infarction still cannot be excluded. The ECG of acute infarction often shows arch-back upward elevation of the ST segment, and some of them may show pathological Q waves. The serum marker of myocardial injury, troponin, has the best sensitivity and specificity, and a sharp elevation can confirm the diagnosis of infarction. But the most accurate is coronary angiography, which provides specific information about the coronary arteries and prompt treatment. The most important treatment for acute infarction is reperfusion therapy, and thrombolytic therapy can be performed if emergency PCI is not possible. Later treatment such as secondary prevention of coronary heart disease is required.