Variable preexcitation syndrome is one of the preexcitation syndromes, which is a group of syndromes in which sinus node excitation is transmitted down through Mahaim’s fibers and the electrocardiogram shows delta waves and a widened QRS cluster with normal P-R interval, with or without supraventricular tachycardia. Its pathogenesis is mainly due to the presence of an additional conduction pathway between the atria and the ventricles, which is the most fundamental cause, and which is faster than normal conduction. This additional pathway excites the ventricles in advance of the normal atrial conduction, when the excitation has not yet reached the ventricles, so that this pre-excitation syndrome occurs. The treatment of this disease can be closely monitored if it is not accompanied by a fast rhythm, and if there are frequent episodes of supraventricular tachycardia, this condition needs to be treated with radiofrequency ablation.