The typical symptoms of acute myocardial infarction are severe chest pain radiating to the left shoulder, left back, left upper limb or finger ends, and even toothache and sore throat, which usually last for a long time and cannot be relieved by nitroglycerin. Some patients with myocardial infarction do not have chest pain symptoms, but show unbearable pain in the upper abdomen, which cannot be relieved by painkillers and is easily misdiagnosed clinically. In addition, myocardial infarction may have dyspnea and shortness of breath, and patients feel suffocating in the chest and sweating profusely, accompanied by nausea and vomiting symptoms.