Clinical manifestations 1. Symptoms (1) Typical chest pain Triggered by physical activity and emotional excitement, sudden pain in the precordial region, mostly episodic colic or crushing pain, can also be a feeling of suffocation. The pain starts from the posterior sternum or precordial area and radiates upward to the left shoulder, arm, and even the little finger and ring finger. The site of chest pain dispersion may also involve the neck, jaw, teeth, abdomen, etc. Chest pain can also appear in the quiet state or at night and is caused by coronary spasm, also known as variant angina pectoris. If the nature of chest pain changes, such as the newly emerged progressive chest pain, the pain threshold gradually decreases to the point that it can also occur during slight physical activity or emotional excitement or even at rest or when sleeping. The pain gradually increases, frequency, and lengthens in duration, and cannot be relieved by removing the trigger or taking nitroglycerin, then unstable angina is often suspected. (2) need to pay attention to A part of the patient’s symptoms are not typical, only manifested as anterior heart area discomfort, palpitations or weakness, or gastrointestinal symptoms mainly. Certain patients may have no pain, such as the elderly and diabetic patients. (3) Sudden death About 1/3 of patients with a first episode of coronary artery disease present with sudden death. (4) Other systemic symptoms, such as fever, sweating, panic, nausea, vomiting, etc., may be present. Patients with combined heart failure may present 2. Signs Patients with angina are not special when they do not have an attack. Patients may have diminished heart sounds and pericardial friction sounds. If there is septal perforation or papillary muscle insufficiency, murmurs can be heard in the corresponding area. In case of arrhythmia, the heart rhythm is irregular on auscultation.