Low sensitivity of abbreviated tilt table testing for diagnosing postural tachycardia syndrome in adults with ME/CFS, 2018, van Campen, Rowe & Visser

Andy

Andy

Senior Member (Voting rights)
Introduction: Orthostatic intolerance is common among individuals with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). In some ME/CFS case definitions, orthostatic intolerance is considered a core feature of the disorder. Some studies have employed tilt table tests lasting 2-5 minutes to diagnose one common form of orthostatic intolerance, postural tachycardia syndrome (POTS). We examined the diagnostic yield of abbreviated durations of tilt testing in adults meeting criteria for ME/CFS, and identified the proportion with POTS misdiagnosed using testing of less than 10 minutes.

Methods: Eligible participants were consecutive individuals satisfying study criteria for ME/CFS and POTS evaluated at the Stichting CardioZorg (SCZ, Hoofddorp, NL) between November 2012 and August 2018. Individuals being treated with medications commonly used to manage orthostatic intolerance were excluded. Head-up tilt table testing involved 15 minutes of supine posture then 20 minutes at 70 degrees upright. Only the data from the first 10-minutes upright were used. POTS was defined as an increase in HR during a maximum of 10 minutes of upright tilt of at least 30 beats per minute (bpm), in the absence of either classical or delayed orthostatic hypotension. We measured the time until HR criteria for POTS were reached using survival curves, and compared survival curves between subgroups divided by age, sex, disease duration, and degree of hypocapnia during the test.

Results: Of 627 individuals with ME/CFS evaluated during the study period, 155 met criteria for POTS. The median time to reaching HR criteria for POTS was 3 minutes. A two-minute tilt table test would miss 55% (95% CI, 48 - 63%) of those meeting POTS criteria over the course of 10 minutes upright. The median time to reaching HR criteria for POTS did not differ by sex, age, duration of ME/CFS, or hypocapnia during tilt.

Conclusions: Abbreviated tilt table testing misses a substantial proportion of those ultimately diagnosed with POTS during a 10-minute tilt table test, and should be abandoned for the clinical diagnosis and in epidemiologic studies designed to estimate the prevalence of POTS among those with ME/CFS.
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Abstract only at moment, https://www.frontiersin.org/articles/10.3389/fped.2018.00349/abstract
 
Well, that is quite interesting. Thanks @Andy. I would also be interested in the comparison of poor man's tilt table test with tilt table test (or does that exist?).
 
Coincides with their paper
Passive standing tests for the office diagnosis of postural tachycardia syndrome: New methodological considerations (Peter Rowe team 2018) discussed in this thread.

I was recently turned down for an assessment for POTS from my local hospital and am considering trying the NASA 10 minutes lean test myself at home. https://batemanhornecenter.org/wp-content/uploads/2016/09/NASA-Lean-Test-Instructions.pdf

Seems very few doctors here in Norway have heard about POTS. The first patient who got diagnosed was in 2015. I got the impression that my local hospital turns down referrals because they believe this is just a fad among people having read about it on internet.
 
Kalliope said:
Coincides with their paper
Passive standing tests for the office diagnosis of postural tachycardia syndrome: New methodological considerations (Peter Rowe team 2018) discussed in this thread.

I was recently turned down for an assessment for POTS from my local hospital and am considering trying the NASA 10 minutes lean test myself at home. https://batemanhornecenter.org/wp-content/uploads/2016/09/NASA-Lean-Test-Instructions.pdf

Seems very few doctors here in Norway have heard about POTS. The first patient who got diagnosed was in 2015. I got the impression that my local hospital turns down referrals because they believe this is just a fad among people having read about it on internet.
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I did the poor mans ttt at home and qualified for POTS in the first minute of standing. I’m now pushing for a referral to Riksen, where they apparently have a tilt table, but of course GP haven’t heard of POTS or OI so doesn’t see the point.
 
This was mentioned elsewhere and I’m trying to understand which symptoms the participants had, other than changes in HR and BP when standing.

All individuals in this study had chronic orthostatic symptoms.
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This says nothing about which symptoms.
The proportion of individuals with ME/CFS who have exaggerated postural tachycardia during tilt in the absence of chronic orthostatic intolerance symptoms is difficult to determine.
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So is POT not a symptoms of OI in their mind? Meaning that OI refers to other symptoms when standing/sitting, presumably ones that make you feel unwell?
All those with ME/CFS have chronic symptoms of fatigue and exercise intolerance, which are viewed in the autonomic literature to be features consistent with orthostatic intolerance.
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I do not understand what it means that these features are «consistent with OI».
A high proportion with ME/CFS have lightheadedness, 96% in some studies (5), and 61% report intolerance of being on their feet (28).
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Is that lightheadedness only when standing, or made worse by standing? And this presumably means that 39 % do not have intolerance of being on their feet - i.e. not orthostatic intolerance?
Across several studies, over 90% with ME/CFS report cognitive dysfunction, but in most ME/CFS studies, little effort is made to distinguish whether these symptoms are a consequence of orthostatic stress or due to some other contributor to ME/CFS pathophysiology.
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This is a good point.
Some of the variability in the reporting of orthostatic symptoms in the ME/CFS literature is due to differences in the comprehensiveness with which orthostatic intolerance symptoms are ascertained (11).
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It would have been good if this paper could have clarified it.
We are not aware of data reporting an exaggerated tachycardia among those with ME/CFS in the absence of chronic orthostatic symptoms.
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Time has shown that that is pretty normal in healthy people.
 
duncan said:
Why do we care? In particular, why do we care especially if POTS is a subset of OI, which it likely is? It feels like you're crossing i's and dotting t's....
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Because the labelling is so vague and I want to know what the patients are reporting and not which arbitrary label a clinician decides to give it.
duncan said:
I'd warn against getting too locked into contrived definitions, but that seems obvious.
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I agree, which is why I’m asking about the symptoms.

Lots of people feel unwell while upright. Some have increased HR as well, others don’t.
Lots of people have increased HR when standing. Some have symptoms as well, others don’t.

When I talk to people they just say they have POTS or OI, but that doesn’t tell me anything about what they experience happening to them when upright. That’s what I’m interested in learning more about.
 
Utsikt said:
When I talk to people they just say they have POTS or OI, but that doesn’t tell me anything about what they experience happening to them when upright. That’s what I’m interested in learning more about.
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I'm confused. OI is about sensations. POTS is definitional according to BP and HR - this omitting any nonsense from entities with a horse in the race.

What falls beneath either banner is political.

Is POTS real? Is an unmarried widower a bachelor?

I don't need to parse down further. I've lived this far too many incarnations.

But.

You may be right.
 
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