The causes of left heart failure include the following: 1. Primary myocardial damage, such as myocardial infarction, coronary atherosclerotic heart disease, immune response, or hypertrophic cardiomyopathy, which can lead to palpitation damage, and for secondary myocardial damage, such as metabolic diseases and connective tissue diseases, which can also lead to myocardial damage. 2. Overload of the heart, such as when the patient has hypertension, etc., which can also lead to left heart failure. 3. 3. Excessive pressure load on the heart, such as pulmonary hypertension and aortic stenosis, and excessive volume load, such as hyperthyroidism and valvular insufficiency, can cause left heart failure. 4. There are also certain precipitating factors for left heart failure, such as infection, arrhythmia, increased blood volume, or improper medication, which are all causes of left heart failure. These conditions are all causes of left heart failure.