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    Created in 2008, Phoenix Rising is the largest and oldest forum dedicated to furthering the understanding of, and finding treatments for, complex chronic illnesses such as chronic fatigue syndrome (ME/CFS), fibromyalgia, long COVID, postural orthostatic tachycardia syndrome (POTS), mast cell activation syndrome (MCAS), and allied diseases.

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  1. M

    What is the connection between orthostatic intolerance and impaired oxygen extraction?

    I often see ME/CFS patients that undergo exercise tests to be diagnosed with two problems: orthostatic intolerance (preload failure) and impaired oxygen extraction (mitochondrial dysfunction). They seem to be pretty well connected, but I've never seen anyone explaining which one is driving the...
  2. M

    Where can I find where ICPETs are available? Is there any data repository?

    I think I would benefit from an ICPET. Unfortunately they are not available in my country for diagnostic purposes. I had a consultation last year at Brigham with Dr Systrom, and I am technically booked for one there, but it is really for insurance assessment purposes. And they are really...
  3. M

    Is there an easy way to measure aerobic threshold?

    Ok, here is my issue. Like many of you, I have exertional intolerance. Mine is usually presented not as fatigue though, but as pain. I can go swimming for a little bit and be fine. However, I can extrapolate on intensity and experience post-exertional pain, tingling, petechiae, etc. That will...
  4. Pyrrhus

    Exercise Intolerance: Insights from Invasive Cardiopulmonary Exercise Testing of Patients with ME/CFS (Joseph et al., 2021)

    A new publication by the team of Phillip Joseph, Anne Oaklander, and David Systrom, which I personally find exciting. Insights from Invasive Cardiopulmonary Exercise Testing of Patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (Joseph et al., 2021)...
  5. Rebeccare

    Advanced/Invasive CPET?

    I recently saw Dr. Systrom at Brigham and Women's Hospital in Boston, and he suggested having an advanced CPET (the kind where they put in a couple of catheters before you exercise). Have any of you ever had this test before? What did it feel like? How did it go? Did you recover easily? Did...
  6. Kyla

    Unexplained exertional dyspnea caused by low ventricular filling pressures: results from clinical invasive cardiopulmonary exercise testing

    This isn't about ME, but some of the patients had POTS, and this is discussed in the context of exercise testing. Thought the results might be of interest to some here. I have pulled out one of the relevant sections and quoted it (below the abstract)...