Analysis of misdiagnosis of acute myocardial infarction: overshadowed by serious arrhythmia and multiple organ failure. 2.2 The location of pain is not typical of the usual location of pain in the sternum mentioned in the previous paragraph, while in the elderly it may be limited to the abdomen, teeth, throat, neck, shoulders, or back, often misdiagnosed as an acute abdomen, toothache, sore throat, or cervical diseases. 2.3 The clinical manifestations diversify with upper abdominal pain accompanied by nausea, vomiting, bloating, and other gastrointestinal symptoms, often misdiagnosed as acute gastroenteritis, which accounts for 30% of elderly myocardial infarctions, more commonly seen in inferior wall myocardial infarctions due to: (1) cardiac sensory fibers entering the spinal cord and sensory fibers to the upper abdomen polymerize in the same spinal cord neurons, uploaded via the same pathway, thus transmitting the heart's pain impulse to the thalamus and cerebral cortex successors, causing patients to experience upper abdominal pain as an illusion; (2) Vagus nerve fiber successors are almost all located in the heart, where inferior wall myocardial infarction ischemia and hypoxia stimulate the vagus nerve, reflexively acting on the gastrointestinal tract and causing symptoms. Dizziness, fatigue, and disturbance of consciousness are easily misdiagnosed as stroke, due to: elderly individuals simultaneously at risk of coronary artery stenosis also having much more severe cerebral arteriosclerosis, stenosis, and insufficiency, acute myocardial infarction leads to a reduced cardiac output, resulting in increased cerebral arterial insufficiency, or even cerebral infarction, known as heart stroke, occurring both simultaneously, allowing pain absence, concealing myocardial infarction and leading to missed diagnosis. Heart failure as the first symptom is easily missed in acute myocardial infarction. Domestic and foreign reports indicate that heart failure as the initial symptom in elderly myocardial infarction accounts for 20% to 74%. This is because: elderly coronary heart disease, longer duration, extensive myocardial ischemia, fibrosis, and myocardial aging cause cardiac dysfunction, decreased myocardial compliance, decreased cardiac reserve function, further decline in cardiac output on the basis of acute myocardial infarction, followed by heart failure, severe cases lead to cardiogenic shock. 4 ECG changes are typical (1) small focal infarction. Such myocardial infarct size is small, sometimes only showing T wave inversion, ST segment depression, typical Q spread to ST elevation, often misdiagnosed as angina. (2) Original elderly coronary heart disease with ischemic ST-T changes, acute myocardial infarction, ST segment raises over the previous level, also shifting in T wave, ST-T normalization results in misdiagnosis. (3) Older lesions range widely, more than double or multi-vessel disease, multi-branch vascular occlusion, infarction vector offset, the ECG is not typical. (4) Bundle branch block, repeated infarction, non-Q wave infarction, and so on enable the ECG manifestations to be atypical. 2.5 Clinical doctors lack understanding of the diversification of underlying diseases, clinical manifestations, and atypical ECGs in elderly patients with acute myocardial infarction, overly relying on chest pain and typical ECG characteristics. Measures to reduce misdiagnosis (1) detailed history taking, understanding underlying diseases; (2) routine ECG for the elderly, dynamic observation should be carefully conducted; (3) timely serum cardiac biochemical markers checked, and conditional coronary artery imaging; (4) fully understand the characteristics of elderly patients with acute myocardial infarction.