If pain in the anterior region of the heart occurs in the middle of the night, the first thing to rule out is coronary heart disease and angina. Coronary heart disease, angina pectoris in the unstable angina pectoris, in which lying angina pectoris and variant angina pectoris can occur during sleep. The sudden onset of pain in patients while asleep is often caused by spasm in the coronary arteries of the heart, when the patient’s vessels are often not significantly narrowed, or the narrowing does not exceed 70-75%. Due to the combination of severe spasm, resulting in relative ischemia and hypoxia of the heart, and will eventually appear chest tightness, chest pain and other symptoms. In this case, it is important to go to the hospital for a 24-hour ECG. After wearing a 24-hour ECG, if chest tightness and chest pain suddenly appear during sleep, the ECG recorder can promptly record the ECG waveform at this time. If there are obvious ST-T changes, including ST-segment depression, T-wave inversion, or bow-back elevation of the ST-segment, it is considered that the patient may have unstable angina. Afterwards, the patient delivers the diagnostic report to the cardiologist, who determines whether hospitalization, coronary angiography, and stenting should be performed. If not, beta blockers, ACEIs, and calcium antagonists are administered to reduce the burden on the heart and slow down its contractility.