Whether blood pressure rises or falls in patients with myocardial infarction depends on the site and size of the infarction. If the patient has a relatively small infarct area, the presence of severe chest pain can cause a dramatic increase in blood pressure afterwards. In the case of a particularly large myocardial infarction with an extensive anterior wall, it can affect the function of the heart and cause the patient’s blood pressure to decrease. A special type of myocardial infarction is inferior wall infarction, partially combined with right ventricular infarction, which can lead to intractable hypotension due to right heart failure. It is recommended that a large amount of fluid be rehydrated for a short period of time to raise the blood pressure. Whether the blood pressure is elevated or decreased in patients with myocardial infarction, sufficient attention should be paid to treating high or low blood pressure to reduce the mortality rate of patients with myocardial infarction.