The symptoms of typical angina pectoris manifest as crushing pain in the lower and middle sternum, lasting 3-5 minutes per attack, once a few days or several times a day, radiating to the back and left upper extremity, mostly after exertion or emotional agitation, and disappearing after rest or nitrate preparations. During the attack, there is ST-segment depression, transient ST-segment elevation and emerging T-wave inversion on the ECG, and the ECG returns to normal after the angina subsides. Angina pectoris is a clinical syndrome with episodes of chest pain or chest discomfort caused by acute temporary ischemia and hypoxia of the myocardium due to insufficient coronary artery blood supply. In fact, atypical angina is more common in clinical practice. Symptoms of atypical angina include epigastric pain, nausea and vomiting, dyspepsia, and even sharp or respiratory-related pleuritic pain, sudden dyspnea, etc. It can be said that all discomfort from the teeth to the belly button can be angina. Symptoms are mostly atypical in the elderly, women, diabetics, patients with renal insufficiency and dementia. Of the atypical angina, the severe ones can manifest as syncope. I was on emergency duty the other day when a 60-year-old woman, passing by the hospital entrance, had a sudden syncope and was brought to the emergency room. She felt that the problem was not serious and said that she had been seen in a hospital cardiology and neurology outpatient clinic before because of syncope, and all the tests had been done and no problem was found. In any case, patients with syncope should have an ECG as a rule. This patient’s ECG did not seem to be a big problem, but I found that the patient had an inverted T wave in the aVL lead. aVL lead T wave inversion usually indicates severe coronary artery left trunk lesion or severe triple branch lesion, and she was recommended to be hospitalized or kept under observation, but she did not agree. While she was being persuaded, the patient again syncope and immediately rechecked the ECG, which revealed ST-segment elevation in extensive leads and confirmed the diagnosis of coronary artery disease. Considering the severity of the patient’s symptoms and the low blood pressure during the attack, an emergency coronary angiogram was performed, which confirmed that the patient indeed had severe stenosis in multiple vessels, and the symptoms were relieved after stent implantation. When angina pectoris is suspected, it is very important to repeatedly recheck the ECG during the onset of angina pectoris or angina-like symptoms. Dynamic changes in the ECG are an important clue to the diagnosis of angina pectoris. Therefore, if you have hypertension, diabetes, hyperlipidemia, smoking, family history of coronary heart disease, are over 40 years old, and are given repeated ECGs because of heart discomfort or if a doctor suspects angina, please do not question that you are meeting a responsible doctor who is not trying to make more money, but is afraid of missing a diagnosis of life-threatening angina. If the symptoms of angina, which last significantly longer than before, or appear during light activity, or even at rest or during sleep, appear in combination with syncope, aura of syncope, severe dyspnea, accompanied by a large amount of cold sweat, this is a sign that the condition is very serious and it is best to rush to the hospital urgently. When you get to the hospital, if the doctor thinks that you need to do coronary angiography and implant a coronary stent urgently, you must also listen to the doctor. Open the coronary artery in order to save the dying heart muscle in time, time is heart muscle, time is life.