June 01, 2005
ABSTRACT: Syncope is often benign and self-limited; however, it may sometimes indicate a life-threatening condition. Advanced age, heart disease, and abnormal ECG findings are associated with potentially adverse outcomes. The initial evaluation, which consists of a careful history taking, physical examination, and ECG, often suffices to make the diagnosis. Neurally mediated disorders, the most common cause of syncope, are usually benign. Cardiac syncope, which usually requires admission and further assessment, may result from rhythm disturbances or from outflow obstruction attributable to structural or pathophysiologic mechanisms. Patients with cardiac syncope may be evaluated with echocardiography, Holter monitoring, stress testing, loop event recorders, or electrophysiologic studies. Other causes of syncope include orthostatic hypotension, use of certain medications, a primary neurologic disorder, and psychiatric disturbance. A significant number of patients have unexplained syncope.