The treatment of preexcitation syndrome is divided into emergency disposal medication and recurrence prevention medication, and commonly used medications include drugs such as propafenone. 1. Drugs for emergency treatment: mainly used for the treatment of cis-atrioventricular tachycardia with ineffective vagus nerve stimulation. (1) Conventional medications may include verapamil, propafenone, and diltiazem, which can be taken orally, but more often require intravenous medication for rapid symptomatic improvement. The medication needs to be stopped when the tachycardia symptoms resolve. ECG monitoring should be performed for at least 4h after the use of the drug to prevent the emergence of tip-twisting ventricular tachycardia and other diseases. (2) The presence of cardiac insufficiency needs to be ruled out before applying verapamil, diltiazem, or propafenone. If cardiac insufficiency is present, oral amiodarone can be administered, but for the acute phase more often intravenous medication is needed. Ineffective medication or the presence of hypotension requires electrical cardioversion. (3) For atrial fibrillation or atrial flutter combined with preexcitation, electrical cardioversion is preferred, followed by drugs that may act on the bypass, such as ibutilide and propafenone. The use of verapamil, diltiazem and other drugs is prohibited. 2. Drugs for preventing recurrence: If ablation is not possible, propafenone can be taken orally after ischemic and structural heart disease is ruled out. In the presence of severe organic heart disease, amiodarone is the only oral medication available. It is important to note that radiofrequency ablation is an effective method of eradicating preexcitation syndrome. The above medications need to be used under the supervision of a clinician; prompt hospitalization is recommended for preexcitation syndrome.