Evaluation of the patient with syncope.

Evaluation of the patient who has experienced spontaneous, transient loss of consciousness requires a comprehensive consideration of many disease etiologies. Syncope may be a relatively benign condition with a good prognosis or may be a precursor of subsequent cardiac arrest and sudden death. In this article, the cardiovascular causes of syncope and the role of electrophysiologic testing in the diagnostic evaluation of patients with syncope are discussed.