There are serious contraindications to the use of digitalis drugs, which should not be applied in the event of an emergency, contraindications are preexcitation syndrome with atrial fibrillation, second or third degree atrioventricular block, sick sinus node syndrome, simple diastolic heart failure in the elderly, hypertrophic obstructive cardiomyopathy, severe mitral stenosis accompanied by sinus rhythm without right heart failure, acute myocardial infarction within 24 hours, and so on. All these conditions are contraindications to digitalis should not be applied. In addition, the application of digitalis should not be overdosed, and the patient’s condition must be closely monitored, such as heart rate, blood pressure, pulse, arterial oxygen saturation, and the dosage should be adjusted according to the situation. If nausea, vomiting, anorexia, dizziness, etc. occur after the application of the patient, it is necessary to consider whether it is due to the toxic phenomenon caused by the application of digitalis overdose, and the application must be stopped.