In left heart failure, the main site of stasis is the lungs, and the patient may cough up pink foamy sputum, sit and breathe, and suffocate. In severe left heart failure, total heart failure may occur, and enlargement of the liver and spleen, fluid in the abdominal cavity, and edema of both lower limbs may also occur, all of which are symptoms of heart failure. Once left heart failure occurs, the causes of left heart failure, such as heart valve disease, coronary artery disease, fulminant myocarditis, dilated cardiomyopathy, etc., should be identified through electrocardiogram, cardiac ultrasound, coronary CTA, coronary angiography, etc. Once the causes of left heart failure are known, insist on the use of cardiotonic, diuretic and myocardial-nourishing drugs to bring relief to the heart failure symptoms.