Ttt And Standing Test Are Not The Same: New Article

[firewatcher]

Clin Sci (Lond). 2012 Aug 29. [Epub ahead of print]

Diagnosing Postural Tachycardia Syndrome: Comparison of Tilt Test versus Standing Hemodynamics.

Plash WB, Diedrich A, Biaggioni I, Garland EM, Paranjape SY, Black BK, Dupont WD, Raj SR.

Abstract

Postural tachycardia syndrome (POTS) is characterized by increased heart rate (ΔHR) of ≥30 bpm with symptoms related to upright posture. Active stand (STAND) and passive head-up tilt (TILT) produce different physiological responses. We hypothesized these different responses would affect the ability of individuals to achieve the POTS HR increase criterion. Patients with POTS (n=15) and healthy controls (n=15) underwent 30 min of TILT and STAND testing. ΔHR values were analyzed at 5 min intervals. Receiver Operating Characteristics analysis was performed to determine optimal cut point values of ΔHR for both TILT and STAND. TILT produced larger ΔHR than STAND for all 5 min intervals from 5 min (38±3 bpm vs. 33±3 bpm; P=0.03) to 30 min (51±3 bpm vs. 38±3 bpm; P<0.001). Sensitivity (Sn) of the 30 bpm criterion was similar for all tests (TILT-10=93%, STAND-10=87%, TILT30=100%, and STAND30=93%). Specificity (Sp) of the 30 bpm criterion was less at both 10 and 30 min for TILT (TILT10=40%, TILT30=20%) than STAND (STAND10=67%, STAND30=53%). The optimal ΔHR to discriminate POTS at 10 min were 38 bpm (TILT) and 29 bpm (STAND), and at 30 min were 47 bpm (TILT) and 34 bpm (STAND). Orthostatic tachycardia was greater for TILT (with lower specificity for POTS diagnosis) than STAND at 10 and 30 min. The 30 bpm ΔHR criterion is not suitable for 30 min TILT. Diagnosis of POTS should consider orthostatic intolerance criteria and not be based solely on orthostatic tachycardia regardless of test used. PMID: 22931296 [PubMed - as supplied by publisher]

[arizona girl]

So, are they saying 10 min standing isn't always enough to show pots or that none of the tests are always adequate to prove pots. It would explain why when I went there there 10 min standing test wasn't enough for me. Even though they had tests that showed my bp went up. It took 2 more years before a formal ttt was done by a local doctor that showed the hyper response with syncope. I then went to see grubb, who ordered catchecolamine testing which proved the hyper response. My trip to vanderbilt wasn't that helpful to me, though they did suggest the salt loading in such, which Grubb then said isn't always helpful for hyper pots.

So it seems to me they are reevaluating how they are ruling patients in or out not exclusive to tilt testing alone, but may give more weight to how the patient actually presents? If true that sounds like a step in the right direction. Nice to see it documented for other docs who may not even know what pots is.

[sue1234]

" Diagnosis of POTS should consider orthostatic intolerance criteria and not be based solely on orthostatic tachycardia regardless of test used."

That says it all to me...the doctors can quit trying to say we do or we don't have POTS due to the strict criteria of 30 bpm. If you cannot stand because you feel like fainting, and your heart sped up 17 bpm or 40 bpm, you have a problem. Period.

[AllAboutPeace]

Hmmm, interesting! Thanks for posting this. Based on the last statement alone, I think it would be worth having this in your back pocket when going to docs. I'm going to make sure my doc has a copy.

[Mytwogirlsrox]

Thanks for posting!

[Mytwogirlsrox]

I decided to stand test myself tonight I guess u don't have POTS lol. My HR went from 60 resting to 80 standing at 10 minutes.

I only have POTS in the am apparently lol

[peregrine]

The orthostatic criteria thing is definitely a big one, and I'm glad they mention it! For the standing itself - I've certainly noticed that my own standing results are less dramatic than the TTT results (though still an increase over 30bpm before beta blockers), and many folks have pointed out that it more closely mimics what happens in real life when someone stands.

[Katybug]

I wonder how much oney they spent on this study? I would have thought that anyone could have figured out that the stand test and TTT would give a somewhat different result since a Stand test allows for some amount of countermaneuvers (no matter how still you try to be) while the TTT restrains you much more.

This does bring up an interesting point though which is that my docs recently have been taking my sitting HR (using this as resting) and then taking a standing test. So I usually go from 80ish to 100ish. But, this doesn't really give the full picture, does it? I will say my neuro is really good about noting all my symptoms that happen during the stand test. But, I worry how this looks to the insurance co. and the SSA examiners. If I am not reaching the 30bpm, then its easy for them to say I'm cured.

[Batik]

Any idea what's up if it takes longer than 10 min to get the >30bpm increase? In my case, it can be up to 15 minutes. I don't know how much of this is down to the extremely poor quality of my home tests with my amateur blood pressure monitor, which takes time to inflate, rather than using beat-to-beat fingertip testing, as I've heard Newton recommends. Also I rarely manage to test from lying to standing, usually it's from sitting to standing, and despite my best efforts, I tense up leg/buttock muscles to stop myself from falling, and often sway or fidget. Sometimes I'll have my HR go up something like 27 in the first minute or so, and then shoot up another 10 at about 13 or 15 minutes. Meanwhile my BP will be donig gymnastics, often including alarmingly low pulse pressures such as 15 at various points.

Randomly, does anyone else get itchy a few minutes after standing? Or suddenly break out in a sweat?

[arizona girl]

batix, if you read dr. grubbs article on hyperandregenic pots, getting itchy, jittery clamy/sweaty after standing are some of the symptoms, if your blood pressure is rising on standing that is also an indicator.

I also agree that is the whole point of the ttt is to stop your counter compensating responses so they can see what is really happening. However, even on my ttt my body involuntarily tried to compensate. I had no control to stop my buttocks and legs from contracting and shaking. I think that contributed to me staying up fairly long, I was even standing for about a minute with no measurable blood pressure and only after that happened did my presyncope symptoms start and then I guess I did pass out, though I thought I was still aware of what was going on. As I was going down I said this is what happens to me in real life and can you please put it down now. then pass out, when the put the table down I felt like I'd been slammed to the ground and almost threw up.

After that test I realized that I was indeed the Queen of Compensation and Avoidance, without even realizing it I had been doing all kinds of things to keep me up right. Fortunately it takes extra stressors to trigger the presyncope which I have learned to avoid.

[yogini]

In my mind the orthostatic test is really the right test, since it is what happens in real life. The tilt test seems artificial. But either one should be good enough to diagnose.

[joyagh]

obviously they produce different results. with the stand test you are using your own muscles and their response to gravity, as well as determining how well your skeletal muscle pump is working. I have also read it can take 30 minutes to produce the tachycardia with the TTT.

My tachycardia is worse with stand test than TTT.

[POTLUCK]

Nice post. Thank you.

My personal opinion is these things are a little arbitrary and patients should consider their personal situation and symptoms.

For example the "strict" criteria for Diabetes has changed over the years and the same sugar level fasting and same Oral Glucose Tolerance Test in years past would not have been diagnosed with Diabetes, but now it would.