Syncope in the elderly.

Syncope is a common, potentially dangerous manifestation of transient cerebral dysfunction that often remains unexplained despite medical evaluation. In elderly persons the cause of syncope depends on the accumulation of several age- and disease-related abnormalities that impair adaptation to minor physiologic stresses not ordinarily expected to produce syncope. The evaluation of syncope requires a careful history and physical examination to identify common conditions and physiologic stresses that may present atypically as syncope, as well as conditions such as postural hypotension, aortic stenosis, and carotid hypersensitivity that are often overlooked on routine examination. Laboratory studies have a low sensitivity and specificity in the elderly patient and should be ordered selectively. Therapy should be directed toward preventing recurrent episodes by minimizing risks for syncope and treating symptomatic abnormalities regardless of the age of the patient, but with attention to age-related changes in drug metabolism and action.