Evaluation of syncope.

Syncopal episodes are relatively common. A variety of etiologies can underlie syncope, and the cause is often multifactorial. A thorough history and a complete physical examination are essential initial components in the evaluation of a patient with syncope. Prodromal symptoms often accompany fainting of vasovagal origin, while the occurrence of syncope without warning in a patient with cardiac problems suggests arrhythmia. Many medications, including antihypertensives, antidepressants and digitalis, may be responsible for episodes of fainting. The physical examination of a patient with a history of syncope includes measurement of orthostatic blood pressure, as well as careful cardiovascular and neurologic evaluations. The decision to use ancillary laboratory and electrocardiographic testing is guided by the patient's history and the findings on physical examination. Although new technologies, such as loop electrocardiography and tilt table tests, can aid in the diagnosis of syncope, they should not be used routinely.