When sudden blockage of coronary artery, i.e. acute myocardial infarction occurs, the first manifestation is chest tightness and chest pain, a crushing pain, throat like being stuck, chest like pressing a stone, but the intensity is much greater than angina and persistent, and the patient will have a feeling of near death and accompanied by heavy sweating. However, elderly patients and diabetic patients often have an atypical presentation, which can manifest as toothache, left shoulder pain, back pain, epigastric pain, nausea, and vomiting. The main age of onset of coronary heart disease is after 40 years old for men and after menopause for women; therefore, people of this age should consider the possibility of acute myocardial infarction if they develop the above symptoms. When the above-mentioned symptoms, especially crushing chest tightness and chest pain, appear and acute myocardial infarction is suspected, you should immediately stop physical activities, preferably lie down and rest, and take a nitroglycerin tablet under the tongue. If the chest pain cannot be relieved within 5 minutes and is accompanied by heavy sweating, the possibility of acute myocardial infarction should be considered and the patient should immediately call 120 emergency number and be sent to the hospital urgently. How to help? If you see someone around you suddenly fall to the ground, lose consciousness, and do not respond to the whistle, you should first consider acute myocardial infarction and cardiac arrest. Immediately implement cardiopulmonary resuscitation: first put the patient on the ground, feel the carotid artery to see if there is pulsation, see if the mouth and nose have whistling; if it is determined that the heartbeat and whistling have stopped, then hit the patient’s sternum (the center of the chest) with a fist, then press the lower and middle sternum rhythmically with both palms superimposed at a frequency of 100 times per minute; at the same time remove foreign objects such as dentures from the patient’s mouth, hold up the patient’s jaw, pinch the patient’s nose Inhale deeply and then quickly blow mouth-to-mouth into the patient’s mouth. A person rescue, artificial whistling and cardiac compressions alternately, each compression 15 times blowing 2 times; two people rescue, one person do artificial whistling, one person do cardiac compressions, each compression 7 times, blowing 1 time. 1 minute later re-check the patient carotid pulsation and whistling, to see if there is recovery, if not recovered immediately again cardiac compressions and artificial whistling. At the same time, you should urgently call people passing by and ask for help to call 120 emergency number urgently. Acute myocardial infarction is a disease with a very high death rate, but it is also a preventable disease. Medical epidemiological studies tell us that 90% of myocardial infarction can be prevented as long as we strictly control hypertension, hyperlipidemia, diabetes, maintain a healthy diet and lifestyle, and treat coronary heart disease and angina according to medical advice.