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Evaluation of syncope in adults

Brian Olshansky, MD
Section Editors
Leonard I Ganz, MD, FHRS, FACC
Robert S Hockberger, MD, FACEP
Deputy Editor
Brian C Downey, MD, FACC


Syncope is the abrupt and transient loss of consciousness associated with absence of postural tone, followed by complete and usually rapid spontaneous recovery. Syncope is alarming for the individual, witnesses, family, and physicians.

Syncope is most often benign and self-limited, although it can be a harbinger of a multitude of disease processes. Injuries resulting from syncopal attacks occur in about one-third of patients, and recurrent episodes can be psychologically devastating. In addition, syncope can be a premonitory sign of cardiac arrest, especially in patients with organic heart disease.

Issues relating to the evaluation of syncope in adults will be reviewed here. The approach to the adult patients with syncope in the emergency department, and the pathogenesis, etiology, and management of this disorder in adults are discussed elsewhere. (See "Pathogenesis and etiology of syncope" and "Management of syncope in adults" and "Approach to the adult patient with syncope in the emergency department".)


The cause for syncope is often not obvious, and it can be difficult to identify the individual at risk for sudden death (table 1) [1]. A prospective study of 341 patients found the following distribution of causes [2]:

Reflex (neurally-mediated; this includes vasovagal) – 58 percent


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Literature review current through: Sep 2016. | This topic last updated: Aug 14, 2014.
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