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36bpm HR increase when swallowing: failure of vagus nerve & parasympathetic response

Discussion in 'Autonomic, Cardiovascular, and Respiratory' started by Paintmyturquoise, Apr 15, 2017.

  1. Paintmyturquoise


    I've been strictly pacing below my anaerobic threshold and avoided crashing this year- until recently when I had nerve conductancy testing two weeks ago that's completely undid all my hard resting.

    In PEM, a symptom from last year is again bothering me- high heart rates and breathlessness when eating or drinking. Difficulties swallowing can be an issue due to swollen glands, sinus congestion, muscle weakness, stress etc. In these instances it occurs even when I swallow easily.

    I documented this yesterday (68-92 bpm, laying reclined)

    Today sitting knees up in a crouch position, resting 59 went up to 94bpm. (raised 36bpm).

    Both times I am laying or sitting still in a relaxed position and using a straw to drink.

    Normally, my heart rate goes up to approx 72-74bpm on the first swallow and stabilises around that level, as is normal as part of the 'cardiac chronotropic response':

    The sympathetic chronotropic response causes the heart rate to raise with swallowing, approx 8 beats.
    supine position (13.1 +/- 5.6 bpm)
    standing position (8.5 +/- 3.8 bpm).
    Assuming these are standard deviations, in their normal population 95% of people's HR raised:
    laying flat 2-24bpm
    Standing 1- 16bpm

    According to the study abstract, the parasympathetic nervous system slows heart rate through the action of the vagus nerve. I don't have access to the full study so haven't been able to get further details.

    The response relies on the vagus nerve, which may be lacking tone, or inflamed? in ME/CFS/fibro. Thus in PEM there is sympathetic dominance, the HR isn't slowed by the parasympathetic response, the parsympathetic response may not occur and the heart rate may continue to elevate beyond the third swallow. I'm assuming its inflammation because if it just 'lacked tone' wouldnt this occur all the time and not just in PEM?

    This seems to be readily documentable evidence of vagus nerve problems, specific to PEM, but I haven't seen mention in the literature.

    Thoughts? Experiences? Studies?
    emsho likes this.
  2. halcyon

    halcyon Senior Member


    The vagus nerve also controls part of the esophagus and is involved in swallowing. If possible, you'll probably want to get full autonomic testing and as well as blood tests for acetylcholine autoantibodies (AChR and a3 nAChR).
    Izola and Paintmyturquoise like this.
  3. Paintmyturquoise


    Update: today I woke improved a bit, able to move more under 100bpm, light sensitivity reduced, able to eat.

    Repeat test: 7 swallows of water elevated my heart rate 20bpm only
    Resting 63- peak 83- dropped back to 61.

    This return to bradycardia is noted as part of a parasympethic compensation
  4. Paintmyturquoise


    TY for the info & link!

    - tests were performed in the morning (as mine was), after 10 mins rest in supine position (from resting)
    - a single swallow, three swallows, and five swallows one at a time
    - 7-10 water swallows through a tube (like i did using a straw)
    - - 'deglutination tachycardia= average resting beforehand compared with peak during swallowing
    - there is usually a abrupt initial rise, slow growth, and then recovery
    - acceleration is due to inhibition of vagal activity
    - in normies, 'the contribution of each swallow is lower than that of the previous one'
    (in the attached image, 1 is deglutination tachycardia, 2 is the addition of each bpm for 2 heart beats, across 1,3,5 swallows)

    -in some normies the parasympathetic compensation actually causes HR to drop after. I have noticed this when relatively well/not PEM
    -the mechanism of swallowing is designed to be completed quick;y to allow the resumption of swallowing. i have noticed this can be delayed in PEM, leaving me gasping for air

    Regarding you mentioning the oesophagus, apparently GERD can irritate it.
    - i've noticed throat sensitivity coinciding/following these symptoms, such that eating honey causes me to cough. this is a PEM marker for me, as i eat honey daily

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