The appropriate use of the tilt table test
While the tilt table study can be used to diagnose orthostatic hypotension, this test should virtually never be necessary in patients with this condition, which is easily diagnosed in any physician’s office. The main utility of the tilt table study is in diagnosing vasovagal syncope. Observing a typical vasovagal episode during an upright tilt can solidify a diagnosis that was previously uncertain, and for this reason the tilt table study can occasionally be quite useful.However, the test should be used judiciously. In fact, it should be used only in a minority of patients with vasovagal syncope. In people who have clear-cut vasovagal syncope, the tilt table study reproduces their symptoms only about 70 – 75% of the time. In other words, 25 - 30% of these patients have "false negative" studies. The tilt study, therefore, should not be considered a “gold standard” in the diagnosis of vasovagal syncope. The “gold standard” is still the physician’s careful and complete medical history. In fact, if the clinical history is strongly indicative of vasovagal syncope, performing the test to confirm the diagnosis may – if the study turns out to be negative – confuse rather than solidify what otherwise was a clear picture. For this reason, doctors should probably not routinely order tilt studies in patients who clearly have vasovagal syncope.
The test is best used in patients whose histories are suggestive of vasovagal episodes, but where there is still some doubt. In these patients, a positive tilt study can go a long way in pinning down the diagnosis of vasovagal syncope.
