Alternating pulse patients with a history of hypertension, coronary heart disease, myocardial infarction and dilated cardiomyopathy, along with fatigue, malaise, exertional dyspnea, telangiectasia and nocturnal paroxysmal dyspnea, suggesting left heart failure; cardiac folk chest tightness, malaise, suggesting arrhythmia, such as paroxysmal tachycardia or atrial tonicity; the original congestive heart failure, especially in patients with atrial fibrillation, and the emergence of cardiac medicine during the application of digitalis Chest tightness, nausea J vomiting, suggesting digitalis poisoning. Signs and symptoms Cardiac examination reveals that the heart is enlarged (the left heart is enlarged and the heart rate of the main person is increased, diastolic gallop rhythm is detected, and there are wet rhonchi at the bottom of both lungs, suggesting left heart failure; the patient has jugular vein pulsation, and the auscultation of tachycardia or arrhythmia suggests cardiac arrhythmia. X-ray: The shape of the heart is enlarged, mainly in the left heart, and there is pulmonary stasis, which suggests left heart failure. 2.Electrocardiogram (ECG) A positive P-wave terminal vector (PtfV1) in lead V1 of ECG is a common and important indicator for diagnosing left. It has been a common and important indicator of insufficiency. In addition, ECG has specific diagnostic value for the diagnosis of digitalis intoxication, paroxysmal tachycardia and atrial tachycardia. 3, Echocardiography The left has been enlarged, mainly left ventricular enlargement, the volume per beat (SV) and cardiac output (CO) is reduced, the ejection fraction (EF) is reduced <0.50, Gu left heart insufficiency. 4.Radionuclide and magnetic resonance imaging can determine the left ventricular end-systolic and end-diastolic volumes and ejection withdrawal. 5.Traumatic hemodynamic examination Floating catheter can measure pulmonary capillary wedge pressure, cardiac output (CO), cardiac index (CO), which is an important index for diagnosing left heart insufficiency.