Propafenone hydrochloride tablets for the treatment of cardiac arrhythmias. The drug is an antiarrhythmic drug with membrane stability and sodium channel blocking effect, which not only has the blocking effect of class II antiarrhythmic drugs, but also slows down impulse conduction by decreasing the rate of action potential elevation, thus prolonging the atrial and AV node and ventricular period of inactivity. Therefore, the drug is used clinically to treat symptomatic supraventricular tachycardia, such as atrioventricular junctional tachycardia, WPW syndrome combined with supraventricular tachycardia or paroxysmal atrial fibrillation; and ventricular tachycardia judged by an internist to be therapeutic or fatal. Adverse reactions such as dizziness, headache, nausea, diarrhea, and fatigue during administration. The drug is contraindicated in patients with uncontrolled congestive heart failure, severe symptomatic bradycardia, severe hypotension, significant electrolyte disturbances, severe obstructive pulmonary disease, and myasthenia gravis. It should be used with caution in pregnant and lactating women. If the drug is needed, it should be used under the guidance of a specialist.