Propafenone hydrochloride is a class I anti-arrhythmic agent with basic local anaesthetic and membrane-stabilizing properties. Some P-adrenergic blocking action has also been described. Propafenone decreases the depolarization velocity and slows conduction in the His-Purkinje system with resultant increase in the PR interval and the QRS complex. Propafenone is used in the treatment of paroxysmal supraventricular tachycardias and ventricular arrhythmias.