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Heart rate variability may help to understand chronic fatigue syndrome (CFS)

Discussion in 'Latest ME/CFS Research' started by Firestormm, Nov 15, 2012.

  1. Firestormm

    Firestormm Guest

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    Plos One Research: Published 14 November 2012: http://www.plosone.org/article/info:doi/10.1371/journal.pone.0049518#abstract0

    News Medical Report: http://www.news-medical.net/news/20121115/Heart-rate-variability-may-help-to-understand-chronic-fatigue-syndrome-(CFS).aspx

    taniaaust1, Skyline and Simon like this.
  2. Firestormm

    Firestormm Guest

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    And I thought the research had all gone quiet! Two in one day. Must be Xmas :)
    vli likes this.
  3. xchocoholic

    xchocoholic Senior Member

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    Correct me if I'm wrong but in't this just another way of saying that pwcs with orthostatic intolerance (oi)
    will have cognitive problems ? If so, how do they expect biofeedback to correct oi ?

    Also, they refer to our inability to sleep as meaning our bodies are stuck in fight or flight mode but I can't see how that relates to oi. I can always think more clearly when I'm supine.

    I "think" they're drawing a conclusion which doesn't exist.

    Tx .. X
    Allyson and Valentijn like this.
  4. Esther12

    Esther12 Senior Member

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    For things like this and the HPA findings, I do wonder if they are secondary to patients suffering from health problems (of whatever cause), then facing the quackery that surrounds CFS, and this then leading to changes in stress responses, etc. Whenever there are widespread findings for CFS patients I tend to suspect that it's secondary... nice to see that they seem to have matched activity levels though, as that's one way people have claimed these sorts of results are secondary in the past. Julia Newton's done similar stuff in this area, but it's not something I've been keeping a close eye on.
    Allyson likes this.
  5. Valentijn

    Valentijn Activity Level: 3

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    The impression I get is that the study found a correlation between two symptoms (heart rate variability and cognitive problems), then some of the researchers reached the usual stupid assumptions regarding the underlying cause, with absolutely no proof whatsoever.

    It's probably an attempt to reconcile their physiological discoveries with all the bad psychological research regarding curing ME/CFS with CBT and GET. Four psychiatrists are listed as authors, and two people with backgrounds in real medicine.

    I'm really sick of seeing this sort of compromise. It just makes both camps sound like idiots. Why can't they just say "HRV influences cognitive performance. We don't why - further research is needed." Instead they write a complete work of fiction to get from point A (physiological signs) to point Z (psychological cure).
  6. Sean

    Sean Senior Member

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    It's pathetic, isn't it. (And the reviewers are just as much to blame for letting it through.)

    Pity, as it is otherwise a useful (though unsurprising) finding.
  7. biophile

    biophile Places I'd rather be.

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    I initially misread the sentence and agreed with it until I realized my mistake:

    "Even when they sleep, their stress-responsive neural systems are on high alert, signalling that it is not safe to relax. I think the abnormal response to stress in this condition may be understood by biological analogy to post-traumatic stress disorder, just that in CFS the ongoing trauma is most likely a physiological, internal one, such as multi-system disease."

    Ironic if a "psychosocial" aspect of BPS for CFS involves quackery involving the BPS model for CFS.
  8. Esther12

    Esther12 Senior Member

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    I'd be amazed if the BPS approach to CFS had not caused psychosocial harm to most patients. It's had such a profound affect by encouraging unreasonable social responses to patients.
  9. Snow Leopard

    Snow Leopard Senior Member

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    I wonder about the HRV of severely fatigued healthy people - eg those who have underwent severe fatigue during military training or perhaps as training/testing for the space programmes etc?

    HRV seems to be low across the board in many illnesses, from anxiety to Rheumatoid arthritis. It seems to be a fairly nonspecific marker unfortunately.
    Dolphin and Simon like this.
  10. Snow Leopard

    Snow Leopard Senior Member

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    Simon likes this.
  11. WillowJ

    WillowJ Senior Member

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    that's very interesting. Flattened T-waves (which Dr. Lerner finds in his patients) are also found in athletes (example). (of course flat t wave could be from hypokalemia [low potassium] as well)
  12. Simon

    Simon

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    Cort has now blogged about this study

    Some comments from me, based on the full text

    Heart Rate Variability a moderate predictor of cognitive performance in patients
    • Just as it is in controls in this study and in healthy people in other studies too. Maybe it would have been more surprising if it hadn't predicted cognitive performance. "As disease status was not an independent predictor, this suggests a broader role for low HRV in mental flexibility in general"
    • HRV only explains about 25% of the variance in results, so it's a significant but not huge predictor of performance
    Mental fatigue, and perceived effort were not predictors of performance
    • In some ways very surprising, but in line with other studies, including this recent one from Susan Cockshell
    • Same applied to mental energy, both before and after tests and for other symptoms. In all cases there were large differences between patients and controls at the group level, but none of these measures predicted differences in cognitive performance for individuals.
    Heart Rate of patients took MUCH longer to recover after mental exertion

    This was probably the most striking robust finding of the study, and this first time this phenomena has been observed in CFS patients. Note the average time was TWICE as long to recovery:
    This slow recovery is probably the best evidence within the study for dysfunctional vagal activity.

    Lots of speculation
    • There was a long discusiioin with much hypothesising: "postulated, speculative, consistent with..." etc. May be right, but the model presented and much of the speculation went well beyond the evidence presented.
    • As the authors point out, they would have to do a series of new and very different studies to validate the hypothesis, eg the proposed role for the PreFontal Cortex
    • Personally, I think the use of PTSD as an analogy was unfortunate as the model presented was rooted in physiological changes.
    • Weaknesses acknowledged in the paper:
    Summary
    • The HRV link to cognitive performance found in CFS patients was the same as that found in controls, and isn't very surprising
    • The inability of symptoms inc mental fatigue/effort to predict performance is more surprising
    • The very slow recovery of Heart Rate to resting levels following exertion is a new finding and a very marked effect
    One final point, patients exercised moderately (eg brisk walking) for an average of 3.5 hours a week (same as controls), which probably makes them pretty-high functioning patients. The patients were recruited from a clinical CBT/GET programme.
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  13. jeffrez

    jeffrez Senior Member

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    I think it's a good study. Not only clearly shows both cognitive and autonomic dysfunction in CFS compared to controls, but also a possible physiological reason for cog dysfunction in the differences that also are found in HRV and autonomic function between CFSers and normals. They need to go further and find out the neurological or neurocognitive causes of the vagal/autonomic issues. Perhaps then EEG neurofeedback practitioners can zero in on the cause better and we can treat it more effectively.
  14. taniaaust1

    taniaaust1 Senior Member

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    :rolleyes: I wish they'd stop using patiences for ME/CFS studies who can clearly exercise okay on top of what they already do!! Using patients who are able to do CBT/GET doesnt apply to many of us.

    If they truely want to see problems in the ME/CFS patients why dont they start actually using a lot more sicker patients in their studies!!!
  15. taniaaust1

    taniaaust1 Senior Member

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    It is well known that too much bed rest "can" cause autonomic dysfunction such as POTS. I wouldnt be surprised if the psych field peoples say its the time we spend laying which is causing our issues.
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  16. jeffrez

    jeffrez Senior Member

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    Haha! I was talking more about brainwaves, but I'm sure some would say that, like lying in a coma is what's causing the coma, lol.
    xchocoholic and Allyson like this.
  17. Allyson

    Allyson *****

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    @Tania - was that a joke about the bedrest causing POTS?

    If not why does everyone who lies in bed for two weeks not develop POTS

    That is what a cardioligst said cause my "CFS" - lying in bed for 2 weeks

    When i ksed then why did that not happen to evryone she then said "cfs is psychosomatic" and the treatment is o get up everydy for 3 weeks, have a HOT SHOWER an stay up all day.

    I did not go back.

    A
  18. xchocoholic

    xchocoholic Senior Member

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    I've found that resting on the couch for 3 days in a row makes me get winded easier for about
    a day afterwards but that's it. Once I get moving again, my body adjusts back to my pre-couch
    strength.

    I've also found out numerous times that I can gain muscle strength via exercise. The problem is that
    eventually I get pem or I crash so I can't exercise anymore. I gave up spending my valuable time exercising
    after I learned this.

    I wish they'd come up with some genius protocal for treating oi. I have several possible physical
    reasons (lbbb, lung scaring, brain damage, neck damage, hyperinsulinemia and mast cell disorder)
    that can explain my oi but I have no idea who could figure out what I should do. Btw, I think all my physical
    reasons have all been shown as possible causes of oi via research. I need a genius to unravel this tho.

    Tc ... X
    Valentijn likes this.

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