Heart failure is a group of syndromes caused by the impaired filling and/or ejection capacity of the ventricles due to various structural or functional heart diseases. The clinical manifestations are mainly dyspnea, weakness leading to limitation of physical activity and edema. (Treatment of the disease should include preventing and delaying the onset of heart failure, relieving the symptoms of clinical heart failure, improving its long-term prognosis and reducing mortality). The examination items are: 1, dynamic electrocardiogram (Holter monitoring) Dynamic electrocardiogram is a method that can continuously record and compile and analyze the changes in the electrocardiogram of the human heart in the active and quiet states for a long time. The ECG refers to the successive excitation of the heart by the pacing point, atria, and ventricles during each cardiac cycle, accompanied by changes in ECG bioelectricity, and the graphical representation of multiple forms of potential changes elicited from the body surface by an electrocardiographic tracer (abbreviated as ECG). ECG is an objective indicator of the process of onset, propagation and recovery of cardiac excitation.