1, respiratory tract infection: more common by heart failure when pulmonary stasis easily secondary to bronchitis and pneumonia, if necessary, you can give antimicrobial agents. 2, thrombosis and embolism: long-term bed rest can lead to the formation of venous thrombosis of the lower extremities, dislodging can cause pulmonary embolism, the clinical manifestations of pulmonary embolism is closely related to the size of the embolus, small pulmonary embolism can be asymptomatic, large pulmonary embolism can be manifested as sudden shortness of breath, chest pain, palpitations, hemoptysis and blood pressure drop, while the pulmonary artery pressure increases, right heart failure aggravates, the lungs show turbid sounds, breath sounds decrease with wet rales, some diseases have Pleural friction sounds or pleural effusion, yellow sclera or short bouts of atrial fibrillation may be present. The triangular or garden-shaped deepening shadow appears in the lower lung field 12-36 hours or days after the onset of the disease, and the huge pulmonary artery embolism can lead to cardiogenic shock and sudden death within a few minutes. 3, cardiogenic cirrhosis: from long-term right heart failure, long-term liver stasis and hypoxia, lobular central zone hepatocyte atrophy and connective tissue hyperplasia, portal hypertension in the late stage, manifested as a large amount of ascites, spleen enlargement and cirrhosis. Treatment: ascites still does not subside after cardiac diuretic treatment, and a large amount of ascites affects the cardiopulmonary function is feasible to release fluid by puncture in appropriate amount. 4, electrolyte disorders: often occur during the treatment of heart failure, especially after repeated or long-term application of diuretics, of which hypokalemia and salt loss and hyponatremia syndrome is the most common. (1) hypokalemia: generalized weakness in mild cases and severe arrhythmia in severe cases often aggravate digitalis toxicity. (2) Hyponatremia syndrome: it is caused by large amount of diuresis and restriction of sodium intake, mostly occurs after large amount of diuresis, with rapid onset of weakness, muscle twitching, thirst and loss of appetite. Laboratory tests: blood sodium, chloride and carbon dioxide binding capacity are all low, and the red blood cell pressure product is increased. Treatment should be unrestricted salt and slow intravenous drip of 100-500ml of 3% sodium chloride solution.