For patients with heart disease, if symptoms of chest tightness occur, the patient should first be given a rapid brake depending on the situation, stop all activities and physical exercise, take a sitting or semi-recumbent position with legs hanging down as far as possible, and take a nitrate drug under the tongue, such as nitroglycerin or swallow isosorbide mononitrate. At the same time, quickly call 120 for help and have a professional doctor arrive home with a defibrillator. At this time, the patient should be closely observed to see if the chest tightness can be relieved. If the symptoms are completely relieved by the above treatment, it usually belongs to the acute attack of myocardial ischemia, and the patient can be seen at a later date after observing no reoccurrence of symptoms; if the patient does not relieve or has recurrent attacks, he/she must go to the hospital emergency room quickly for the next treatment.