Myocardial infarction and angina pectoris are different types of coronary atherosclerosis, the main difference lies in the clinical manifestations, electrocardiographic manifestations and changes in myocardial damage markers. 1. Clinical manifestations: angina pectoris patients have a short duration of pain, usually less than 15 minutes, and can be relieved by taking nitroglycerin on their own; myocardial infarction patients have a long duration of pain, ranging from a few hours to a few days, and cannot be relieved by taking nitroglycerin. 2. Electrocardiogram: the electrocardiogram of patients with angina pectoris can show ST-segment depression and T-wave inversion, and the electrocardiogram will be normal after the symptoms are relieved; patients with myocardial infarction will show the elevation of bow-back upward, and pathologic Q-wave will appear. 3. Myocardial injury and necrosis markers: myocardial injury markers are not elevated in patients with angina pectoris, while they are elevated in patients with myocardial infarction. Whether it is angina or myocardial infarction, after the appearance, should go to the hospital in a timely manner, and improve the relevant examination, receive regular treatment.