American family physician
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Syncope is an abrupt, transient, and complete loss of consciousness associated with an inability to maintain postural tone; recovery is rapid and spontaneous. The condition is common, resulting in about 1.7 million emergency department visits in 2019. The immediate cause of syncope is cerebral hypoperfusion, which may occur due to systemic vasodilation, decreased cardiac output, or both. ⋯ Patients are designated as having lower or higher risk of adverse outcomes according to history, physical examination, and electrocardiographic results, which can inform decisions regarding hospital admission. Risk stratification tools, such as the Canadian Syncope Risk Score, may be beneficial in this decision; some tools include cardiac biomarkers as a component. The prognosis of patients with reflex and orthostatic syncope is good; cardiac syncope is more likely to be associated with adverse outcomes.