Sinus rhythm, ST segment abnormality is serious or not, should be combined with the history of comprehensive judgment, in general the ST segment abnormality is mostly considered myocardial ischemia, this situation is not too serious, but if the ST segment elevation is considered myocardial infarction, should be timely consultation. 1. Sinus rhythm is a normal pacing rhythm, while ST abnormalities are often seen in myocardial ischemia, and ST segment depression is often seen in the leads facing the ischemic area, often accompanied by T wave abnormalities. If timely intervention is made in this case, the prognosis of the patient is good and not too serious, such as following the doctor’s instructions to control blood pressure, blood glucose, taking aspirin, metoprolol and other drugs. 2. If the ST segment abnormality is characterized by an upward elevation of the ST segment, acute myocardial infarction should be considered, which is a more serious situation. The nearest chest pain center with the ability to treat should be selected, and reperfusion therapy such as PCI should be performed in an emergency. Clinical ST segment abnormality is also seen in pericarditis, myocarditis, electrolyte abnormality, etc. Therefore, only from the ST segment abnormality can not determine the severity of the disease, it should be combined with the patient’s medical history, cardiac enzyme spectrum and other related examinations to determine the comprehensive.