A tilt table test is a diagnostic test used to help physicians determine the cause of unexplained fainting (syncope) or severe lightheadedness in a patient. There are a number of reasons a patient might faint, including low blood sugar (hypoglycemia), abnormal heart rhythms (e.g., tachycardia or bradycardia) or low blood pressure (hypotension).
The tilt table test assesses whether the patient is fainting as a result of a sudden drop in blood pressure. The change may be to a hyperactive reflex that causes the blood vessels to suddenly widen (dilate), which may be due to dehydration, emotional stress or standing upright for a prolonged period of time. This type of fainting is now known as neurocardiogenic syncope, although many physicians and patients still refer to it as vasovagal syncope.
The tilt table test is conducted on a pivoting table. By securing the patient on his or her back to the tilt table, and then tilting the table upright (head up and feet down), the factors leading to neurocardiogenic syncope may be simulated. This test is designed to detect orthostatic hypotension, one of the most common causes of fainting.