Sinus rhythm is a normal heart rhythm that does not require special treatment. And T wave changes can be divided into low flat or inverted, elevated three cases. 1. Low T wave: coronary heart disease, cardiomyopathy, hypokalemia, etc. can cause low T wave, and it is suggested that patients can do serum ion analysis, cardiac ultrasound and other tests to further clarify the diagnosis. When coronary artery disease and cardiomyopathy cause insufficient blood supply to the myocardium, drugs such as nitrate and β-blocker can be given to treat them; for T-wave flattening caused by hypokalemia, the symptoms of hypokalemia can be improved by taking potassium chloride slow-release tablets or potassium citrate. 2. T-wave inversion: mostly seen in coronary heart disease and myocardial ischemia, etc. Patients may also have some symptoms of discomfort in the precordial area, and need to go to the hospital for formal diagnosis and treatment. 3. T-wave elevation: seen in patients with hyperkalemia and early stage of acute myocardial infarction. Hyperkalemia needs potassium-lowering treatment to correct ionic disorder, and myocardial infarction patients need to do coronary angiography as early as possible to clarify the infarction site and receive regular treatment as early as possible. Of course, whether there is any change of T wave in patients with sinus rhythm needs to be evaluated by professional physicians, and it is recommended that patients consult professional physicians for specific cases.