ST-T change is a common diagnostic term used in electrocardiogram. If it is caused by fast heart rate, palpitation or no conscious symptoms may appear; if it is caused by myocardial ischemia, angina pectoris, myocarditis, etc., chest tightness, shortness of breath, chest pain and other symptoms may appear. 1. ST-T segment represents the process of ventricular repolarization, and the physiological factor of ventricular repolarization problem is often tachycardia, due to the shortening of diastolic filling time of the heart caused by the rapid heart rate, and the reduction of blood supply to the heart, which may cause palpitation, chest tightness and other symptoms, or no conscious symptoms. 2. If ST-T changes are caused by myocarditis, myocardial ischemia, angina pectoris, myocardial infarction, etc., chest tightness, shortness of breath, precordial pain, sometimes accompanied by dizziness, fatigue, dyspnea and other symptoms. If the electrocardiogram shows ST-T changes, you should complete the relevant examinations as soon as possible under the guidance of the doctor to clarify the cause of the disease, so as to avoid delaying the condition of the danger.