Wake up shivering after a nap, often have palpitations and insomnia,

You may have a genetic problem. Most patients with coronary heart disease have normal or basically normal ECG when they are asymptomatic. So normal ECG can't rule out coronary heart disease. So, what are the ECG characteristics of angina pectoris? -when angina symptoms appear, temporary T wave inversion or ST segment depression (downward movement) occurs; When the symptoms disappeared (after rest or nitroglycerin tablets), the ECG returned to normal. Of course, severe ischemia occurs in a few cases (such as more than fifteen minutes), and ECG abnormalities can last for a long time (several days).

On the contrary, patients have no obvious symptoms, but long-term ECG abnormalities (mostly T wave inversion or ST segment depression) are mostly not coronary heart disease, but may be cardiomyopathy and hypertensive heart disease, which is also common in normal people. Some people have T wave inversion of ECG for more than 30 years, and no organic heart disease has been found.