Autosomal dominant disorder characterized by a defective loss of function of cardiac sodium channels.

-Increased risk for ventricular tachyarrhythmias, syncope and sudden cardiac death.

-There are three (Type 1, Type 2, Type 3), however, only type 1 seems to have the increased risk of sudden cardiac death.

-Type 1:

-Increased risk of sudden cardiac death.

-Widened QRS complexes in which the terminal portion are upright in V1 and V2; appear as a bizarre right bundle branch block; terminal portion of the QRS complexes usually has a steep, straight decent.