Syncope and sudden death in the adolescent.

Syncope is the sudden loss of consciousness and postural tone resulting from an abrupt, transient cerebral malfunction, followed by spontaneous recovery. It is common among adolescents and is usually due to a benign neurocardiogenic (vasovagal) etiology. Rarely, syncope is premonitory of sudden death. The physician must be knowledgeable about the characteristics of neurocardiogenic syncope and what distinguishes it from life-threatening causes. Evaluation of syncope should be based on a complete personal and family history, a thorough physical examination, and an electrocardiogram. Risk factors include syncope that is recurrent, exercise-induced, or not neurocardiogenic in nature; accompanying anginal chest pain, palpitations, and/or dyspnea; cardiac disease; seizure activity; athletic competition; and positive family history for conditions associated with sudden death (e.g., hypertrophic cardiomyopathy, long QT syndrome). Adolescents with these risk factors should be referred to a pediatric cardiologist for specialized testing and management.