Isolated PCCD patients typically present with early-onset (age < 50 years), progressive conduction system disease manifest as one or more of the following: Sinus node dysfunction Slowed intra-atrial conduction AV node disease His-Purkinje system disease (ie, bundle branch blocks or fascicular blocks) A degenerative form, in which the conducting system becomes sclerotic, has been referred to as Lenègre-Lev disease.