Comparing Active Standing, Ttt And Ambulatory Hr And Bp Monitoring In Diagnosing Pots

[Guest Alex]

Recent article:

http://www.functionalneurology.com/common/php/portiere.php?ID=acd346fd90567a300b8cf4731bb23c84

Comparison of active standing test, head-up tilt test and 24-h ambulatory heart rate and blood pressure monitoring in diagnosing postural tachycardia.

Abstract

Protocols for the assessment of postural tachycardia differ in both type of orthostatic challenge and test duration. We therefore compared heart rate (HR) and blood pressure responses during an active standing test (AST) and a head-up tilt test (HUT) in 34 patients with orthostatic intolerance and 31 asymptomatic subjects. A subset also performed 24-h ambulatory blood pressure monitoring (ABPM). HR responses were similar between AST and HUT both in asymptomatic and in orthostatic intolerant subjects. Specificity of HR increase ≥30 bpm for orthostatic intolerance was high (above 0.85) with both AST and HUT and was similar at 3 minutes and at 9 minutes. HR changes recorded during self-performed AST (in the context of 24-h ABPM) and circadian HR difference corresponded well to changes recorded during AST in the autonomic laboratory. We conclude that AST and HUT are comparable methods for the assessment of postural tachycardia, that 3-min and 9-min tests are appropriate, and that ABPM is a useful ancillary test in the assessment of orthostatic responses.

You can read the full text if you wish (it's available for free if you click on the link above), but the conclusion is pretty straightforward. Ambulatory BP and HR reading are as good as a TTT for diagnosing POTS.

Alex

[clairc]

The link doesn't work for me but I think this is the same paper:

http://www.functionalneurology.com/materiale_cic/673_XXVIII_1/5810_comparison/article.html

[corina]

Hey that is cool, I recently corresponded with Mojca Kirbis (and other Slovenian ANS doctors) and added her (them) to our European doctors list. She told me that although she didn't finish her study yet (but will within a year) she has a strong interest in ANS dysfunction. It's nice to read an article from her hand! An asset to our dysautonomia doctors community! Thanks for the article Alex! (and Clair!)

[Canadiangirl73]

I remember reading a study in which they said active standing was actually better because the patient uses leg muscles to trigger venous return and you actually had a better idea of what was wrong. On a TTT, those muscles aren't used so even a "normal" person would have a higher increase in HR. I can't find the study but will post it if I come across it again.

[Chaos]

Also wonder about the TTT where they keep your arms at 90 degrees out to the side. How is that relative to a normal position for any of us?

[Guest Alex]

Clairc,

Yes, that's the article. Thanks for posting the alternative link. For some reason the one I initially posted doesn't seem to work for me anymore (the joys of the digital world)

Corina,

awesome to be able to add more drs to that list!

Now, I wondered myself what - if anything - is "natural" about the tilt table, but I guess doctors have their reasons for using this test. There are some articles out there that compare the poor man's tilt test to the "standard" one and while they may or may not favor one over the other, as a POTS patient I can definitely see some of the shortcomings of the real TTT. On the other hand (and I'm not trying to be insensitive here), for those who faint I guess it's safer to be strapped to the table. That's one way to prevent more problems that can occur when fainting (concussions, broken bones and what not) while obtaining some accurate HR and BP readings.

Alex