Sinus rhythm ST-T changes are more common in clinical practice, and need to be combined with the specific condition of the patient for specific analysis: First, normal people are common in young women, usually no uncomfortable symptoms, check cardiac ultrasound, troponin are normal, may have a certain relationship with staying up late, fatigue, generally do not need to deal with. Second, coronary heart disease heart blood supply is insufficient, for example, the patient has no symptoms when the ECG is normal, if there is chest pain, chest tightness and other symptoms will appear ST-T changes in the ECG, this change suggests a serious lack of blood supply to the heart. Third, heart valve disease, especially aortic valve stenosis and incomplete closure, is also prone to such ECG changes, but such ECG changes are often fixed, and a cardiac ultrasound can help clarify. Fourth, patients with myocardial disease, such as myocarditis, can also have such changes. Combining medical history and examination of cardiac ultrasound and troponin can help in the diagnosis of myocarditis.