Under normal circumstances, patients with mild myocardial ischemia do not experience significant dizziness and nausea, but usually have clinical manifestations such as chest tightness, shortness of breath, palpitations, and precordial discomfort. However, patients with severe myocardial ischemia will have obvious dizziness and headache, accompanied by nausea and vomiting. This is because insufficient blood supply to the heart has caused dysfunction of other target organs, such as transient cerebrovascular insufficiency, cerebrovascular spasm, cerebrovascular stenosis and other conditions, which will cause clinical symptoms such as dizziness, headache, nausea and vomiting. In addition, if significant myocardial ischemia occurs for a relatively long time and triggers heart failure, patients may also suffer from cerebrovascular insufficiency of blood supply or acute stroke as a result, for example, if patients have significant cerebral infarction or cerebral embolism, they may also suffer from dizziness and nausea.