Heart failure cannot be detected by ECG, but the ECG in heart failure can be abnormal, for example, there can be tachycardia, P-wave final potential in V1 lead is greater than 0.04, and so on. The diagnosis of heart failure needs to be combined with clinical symptoms, such as chest tightness and shortness of breath, inability to lie down, waking up at night, and bilateral lower extremity edema. Adjunctive tests mainly rely on BNP and NT-proBNP, and can also be combined with cardiac ultrasound to see if the chambers of the heart are enlarged and if the ejection fraction is reduced. For left heart failure, BNP will be significantly increased, ejection fraction is reduced, there are also heart failure with preserved ejection fraction, that is, the symptoms of heart failure are more obvious, but the ejection fraction of cardiac ultrasound is within the normal range, so the examination of heart failure can not rely on the electrocardiogram alone.