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Syncope in adults: Management

David Benditt, MD
Section Editor
Peter Kowey, MD, FACC, FAHA, FHRS
Deputy Editor
Brian C Downey, MD, FACC


Syncope is a clinical syndrome in which transient loss of consciousness (TLOC) is caused by a period of inadequate cerebral nutrient flow, most often the result of an abrupt drop of systemic blood pressure. Typically, the inadequate cerebral nutrient flow is of relatively brief duration (8 to 10 seconds) and, in syncope, is by definition spontaneously self-limited.

Loss of postural tone is inevitable with loss of consciousness, and consequently syncope usually is associated with collapse, which may cause injury due to a fall (such as may occur if the person is standing) or other type of accident (eg, if syncope occurs while driving). Recovery from true syncope is usually complete and rapid, with episodes rarely lasting more than a minute or two. Longer periods of real or apparent loss of consciousness suggest that the event is not syncope or is not syncope alone (eg, syncope resulting in a head injury, thereby prolonging the event).

Syncope is only one of the many potential causes of TLOC. Examples of nonsyncopal causes of TLOC, or apparent TLOC, include seizure disorders, traumatic brain injury (ie, concussion), intoxications, metabolic disturbances, and conversion disorders (ie, psychogenic "pseudosyncope" or "pseudoseizures"). Distinguishing these conditions from true syncope may be challenging, but it is crucial in order to determine appropriate management.

True syncope itself has many possible causes (table 1). Consequently, after the syncopal event has resolved and the patient is hemodynamically stable, the essential next step is establishing the etiology in order to initiate an appropriate diagnostic and treatment strategy to prevent future events as well as to determine prognosis.

Issues relating to the management of syncope in adults will be reviewed here. The pathogenesis and etiology of syncope, and the clinical manifestations and diagnostic evaluation of patients with syncope, are discussed elsewhere. (See "Syncope in adults: Epidemiology, pathogenesis, and etiologies" and "Syncope in adults: Clinical manifestations and diagnostic evaluation".)

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Literature review current through: Oct 2017. | This topic last updated: Aug 10, 2017.
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