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Three Part Question

In [adult patients presenting with syncope], [how effective is tilt table testing] in [diagnosing orthostatic hypotension]?

Search Strategy

Medline (1948 to June Week 4 2011) and Embase (1980 to week 26 2011) using the Ovid interface.
{[(syncope.mp.) OR (exp Syncope, Vasovagal/) OR (exp Syncope/)] AND [(tilt table.mp.) OR (exp Tilt-Table Test/)] AND [(orthostatic hypotension.mp.) OR (postural hypotension.mp.) OR (exp Hypotension, Orthostatic/)]} LIMIT to humans AND english language.

Search Outcome

In Medline 160 papers were found of which one was relevant. In Embase 130 papers were found, one of which was a duplicate of the Medline paper.

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Khurana, R., et al 1996 United States	19 paid volunteers were used as a control group. 66 patients were used, 39 of whom had a diagnosis of orthostatic hypotension, 17 with orthostatic tachycardia, and 10 with vasovagal syncope. The subjects underwent a HUTT at three different angles, 60°, 80°, and 90° for 20 minutes and the results were compared to their diagnoses.	Prospective cohort study	Sensitivity of a 5 minute HUTT in detecting orthostatic hypotension	73%	No reference to statistical power. No reference to ethical approval. Poor presentation of results. Lack of patient demographic data. One volunteer who developed symptoms was removed from the study - could have been useful for specificity calculations?

Comment(s)

There is a surprising lack of evidence for the usage of tilt table testing in the diagnosis of orthostatic hypotension. Despite that, in several results of literature search tilt table testing has been used as a gold standard against other methods, although some of those did go on to mention that this was due to a lack of any better test to use as the gold standard. The study here does show a 5 minute HUTT to have a good sensitivity in detecting the condition but it is of limited value. It can also be noted that in one study that was deemed irrelevant, it was shown that the rate of false positives for vasovagal syncope in HUTT was 13%. That paper did not investigate orthostatic hypotension, but it is an interesting result to bear in mind. Further research into this question would be very useful.

Clinical Bottom Line

There is not enough evidence to answer this question, even though the test does seem to widely used.

References

1. Khurana, R., Nicholas, E. Head-up tilt table test: how far and how long? Clin Auton Res 1996; 335-341