Inclusion Criteria:  1) The history of chronic stable heart failure exceeds 3 months; 2) 18~75 years old; 3) NYHA cardiac function classified as grade II~IV; 4) LVEF≤40%； 5) NT-proBNP≥450pg/ml； 6) All subjects or their guardians must sign the subject consent before entering the trial.  Exclusion Criteria:  1) Patients with the following diseases: valvular heart disease; congenital heart disease; obstruction of left ventricular outflow tract; severe decompensated heart failure; acute coronary syndrome; active myocarditis or pericardial disease; end-stage liver and kidney diseases; malignant tumor; 2) Patients with poor sound transmission windows are examined by transthoracic ultrasound.