POTS is a condition characterized by very rapid heart rates (>40 bpm increase – adolescents; 30 bpm increase – adults) and pooling of blood in the lower body while standing. It has strikingly similar symptoms (fatigue, exercise intolerance, dizziness, nausea, pain, cognitive issues) to chronic fatigue syndrome (ME/CFS) and fibromyalgia, and is often triggered with a flu-like illness. As with ME/CFS and FM, most people with POTS are female.
The idea that postural orthostatic tachycardia syndrome (POTS) is a heterogeneous condition is not new at all. All types of POTS are characterized by increased heart rates upon standing but the underlying physiology differs greatly.
- Neuropathic POTS – caused by decreased vasoconstriction of the blood vessels in the legs and/or abdomen causing blood to pool in the lower body upon standing. Not associated with autoimmune issues according to a 2014 review. Treatment is focused on improving circulation with exercise and vasoconstricting drugs such as Midodrine, droxidropa and Mestinon (pyridostigmine)
- Hyperadrenergic POTS – associated with increased sympathetic nervous system activity which can be caused in multiple ways. Treatment includes exercise, beta blockers and possibly angiotensin receptor blockers and droxidopa.
Exercise has been used in many studies to understand chronic fatigue syndrome (ME/CFS), but nobody until recently has used exercise to try to understand POTS. Exercise is a particularly interesting tool in the case of POTS because exercise intolerance is often present, and because like with fibromyalgia, exercise has become a kind of go-to therapy for POTS.
In these two studies researchers at the Mayo Clinic in Rochester, New York exercised adolescent POTS and ME/CFS patients (in one of the studies) to exhaustion while measuring their heart rates, oxygen usage, anaerobic threshold, ventilation, gas exchange, etc. The hypothesis – POTS is a heterogeneous condition that is caused in several ways. The goal – to elucidate different subsets.
Cardiac responses to exercise distinguish postural orthostatic tachycardia syndrome variants Paolo T. Pianosi1, Darrell R. Schroeder2 & Philip R. Fischer. Physiol Rep, 4 (22), 2016, e13040, doi: 10.14814/phy2.13040
High flow variant postural orthostatic tachycardia syndrome amplifies the cardiac output response to exercise in adolescents Paolo T. Pianosi, Adele H. Goodloe, David Soma, Ken O. Parker, Chad K. Brands & Philip R. Fischer. Physiol Rep, 2 (8), 2014, e12122, doi: 10.14814/phy2.12122
Adolescent Fatigue, POTS, and Recovery: A Guide for Clinicians Sarah J. Kizilbash, MD, Shelley P. Ahrens, RN, CNP, DNP, Barbara K. Bruce, PhD, Gisela Chelimsky, MD, Sherilyn W. Driscoll, MD, Cynthia Harbeck-Weber, PhD, Robin M. Lloyd, MD, Kenneth J. Mack, MD, PhD, Dawn E. Nelson, RN, MSN, Nelly Ninis, MD, MSc, MBBS, Paolo T. Pianosi, MD, Julian M. Stewart, MD, PhD, Karen E. Weiss, PhD, and Philip R. Fischer, MD. Curr Probl Pediatr Adolesc Health Care 2014;44:108-133
Three Flavors
The POTS subsets were hidden at rest. Even the tilt testing – the standard protocol used to diagnose POTS – failed to expose them. Only under the stress of exercise did the subsets show up.
Adolescent POTS patients may look very similar to each other outside but inside some very different problems are present. The differences in cardiac output found were staggering. In general, average cardiac output or Q should rise ~5–6 l/min during exercise. Most of the 209 patients in the study (70%) exhibited normal increases in cardiac output during exercise (5.5 l/min), but 15% of the group had very low cardiac output (2.25 l/m), and 15% had very high cardiac outputs (9.74 l/min).
The POTS patients with low cardiac output were called “hypokinetic”, while those with high cardiac output were termed “hyperkinetic”. The others were termed normal.
Hyperkinetic – The high cardiac output seen in the “hyperkinetic” POTS group attempts to compensate for problems constricting their blood vessels. During exercise our blood vessels should narrow in order to develop enough pressure (perfusion pressure) to force more blood into our tissues. In the hyperkinetic group, however, their blood vessels remain open; instead the group kicks their heart output up in order to produce the needed perfusion pressure.
That compensatory effort – like so many compensatory efforts in the body – is not entirely successful. These patients get lots of blood flowing through their systems but still get reduced oxygen extraction at the muscles. The authors noted that the reduced oxygen extraction could be due to metabolic issues but they believe is probably simply a blood flow problem. They characterized these patients’ muscles as starving in the land of plenty – and becoming fatigued because of it.
Unlike the hypokinetic group, these patients do not have problems with blood volume or preload.
The Hypokinetic Group – Hypokinetic POTS patients have the opposite problem; their low blood volume and decreased blood vessel capacity means they can’t increase their cardiac output. Instead, they tighten down their blood vessels in order to apply pressure.
In 2004 Stewart called this group of patients the “low-flow” group. Low blood volume clearly plays a major role. These patients’ low calf blood volumes, reduced venous capacitance and tightened down blood vessels left Stewart describing them as being “chronically vasoconstricted”. The “muscle pump” that’s supposed to kick in to keep their blood from draining into their lower body when they stood isn’t working either.
This study indicates that this group of POTS patients also has reduced stroke volume (cardiac output) due to reduced preload. Reduced preload – or the inability to fill the heart with enough blood to pump it out in normal amounts – is same problem that Systrom uncovered in his large exercise study of patients with unexplained exercise problems.
The only thing the body can do to combat a problem like this is to clamp down on the blood vessels in an attempt to build up enough pressure to get the blood to the tissues (e.g. perfusion pressure again).
A POTS Scenario
These are Mayo Clinic researchers; which means they’re big on exercise and deconditioning. Their POTS scenario begins with a physiological problem and ends in deconditioning.
One scenario suggests that a dysfunctional renin-angiotensin system impairs the sympathetic nervous systems ability to regulate blood volume – and down the blood volume goes. At this point the muscles and heart are still working fine,
Exercise exposed three different types of POTS
but further sympathetic nervous system problems impair the ability of the blood vessels to tighten down and apply enough pressure to shoot the blood into the exercising muscles.
The fatigue and dizziness experienced cause POTS patients to pull back. As deconditioning sets in the muscle pump drops out and the capacitance of the veins to store blood drops. That reduces preload to the heart, which produces smaller hearts and lower cardiac outputs.
It’s important to note that POTS is more than deconditioning. Problems with the blood vessels, blood volume or sympathetic nervous system functioning also abound but deconditioning adds significantly to the burden POTS patients experience.
The Chronic Fatigue Syndrome Adolescents
The changes seen in the adolescent ME/CFS patients – lower left ventricular mass and higher pulse – were consistent with physical deconditioning and/or altered sympathetic-parasympathetic balance. The fact that they did not display the increased cardiac output found in the hyperkinetic POTS patients indicated that they were fundamentally different from them.
While it’s hard to find a report which states when deconditioning begins (i.e. how much bed rest it takes) or the minimum level of activity necessary to stave it off (i.e. how many steps per day), deconditioning probably places its own special burden on many people with ME/CFS who cannot be active.
Many studies show evidence of sympathetic/parasympathetic (SNS/PNS) problems in ME/CFS and POTS, and the authors noted that the inability to reduce the heart rate to normal levels after exercise is indicative of parasympathetic nervous system failure. In the end, though, the authors appeared to discard the SNS/PNS possibility in ME/CFS and simply stated that exercise “ought to be an effective remedy for” both POTS patients and ME/CFS.
Treatment Implications
The basics of POTS treatment are pretty simple; increase blood volume (increased fluid – 65-80 oz/day) and salt intake), exercise to the extent possible (start off very low), avoid stressors and perhaps take appropriate drugs and use other aids (compression stockings).
The Mayo Clinic authors stress that deconditioning adds a further stressor to many POTS patients’ lives. They don’t appear to believe that exercise can cure most POTS patients but they do present the possibility that supine exercise might fix some of the circulatory issues that hyperkinetic or high blood flow POTS patients experience. Exercising in the supine position should allow POTS patients to direct more blood to their working muscles because they’re not experiencing blood pooling in their lower body.
The Gist
Low flow or hypokinetic POTS patients suffering from low circulatory capacitance, preload failure and possibly small hearts, definitely need to have their blood volume enhanced. Ways to enhance blood volume include an oral rehydration solution one can easily make at home which may rival saline solution in effectiveness.
The authors do not provide treatment recommendations but the study’s conclusions appear to suggest that
- Vasoconstricting drugs such as midodrine, droxidropa and Mestinon (pyridostigmine) may be more helpful in hyperkinetic POTS patients
- Blood volume enhancing drugs such as fludrocortisone, desmopressin and beta blockers (propanolol, metropolol, atenolol) which increase venous return to the heart might be more helpful in hypokinetic POTS patients
Neuromuscular Strain Impairing Ability to Exercise? – Dr. Rowe’s finding that adolescents with ME/CFS (and surely those with FM as well) experience pain when elongating their tendons during simple movements (let alone during exercise), throws another factor into the fire.
At the IACFS/ME conference, Rowe stated that special exercises to address the stuck tendon problems allowed adolescent patients to engage in more exercise. We’ll cover that finding in the IACFS/ME Conference treatment blog.
- Check out resources on orthostatic Intolerance and POTS including home tests to determine if you have POTS or hyperventilation in HR’s OI and Dysautonomia Resource Section.
Ferritin is a very poor substitute for measuring iron. Its cheap and easy, which is why its used. Iron correlates with ferritin only moderately, and indeed the iron overload disorder is about the eighth most common cause of high ferritin. The number one is alcoholism though that is highly unlikely in an ME patient, and likely to be a problem in any OI patient, quite aside from ferritin. Low ferritin is probably a better marker of low iron than high ferritin is of high iron. I am an haemochromatosis carrier, have very high ferritin, which is a general inflammatory marker, but am almost anemic from low iron.
Multiple subgroups are also indicated for ME, but CFS diagnoses are likely to be many different things mashed together, including misdiagnoses.
Thanks for passing on your experience. Mayo is very focused, apparently, on low ferritin levels – so hopefully those are better measure than high ferritin levels as you note.
Alex, I am also a hemochromatosis gene carrier with high ferritin -but despite normal appearing iron panel I had zero iron stores in bone marrow requiring series 12 weekly iron IVs. Why/ how is it we both could even be deficient in iron in first place when we supposedly absorb more from food than others do per our genetics??? Do you by chance have mold toxicity also? (It causes severe iron deficiency which is actually cause of death of actress Brittany Murphy and her husband who both dropped dead suddenly from same cause months apart). I felt better after receiving iron IVs but the effect lasted a few days only and I wanted doc to continue them until energy improved from one infusion to the next (7 days apart) but docs refused to continue giving them to me due to the elevated ferritin. (At that point no one had discovered I had the positive gene yet). The docs are puzzled as to how someone with my genetics could have had zero iron stores in the first place? Can you explain? Also what are the other 7 most common causes of high ferritinyou mention? Who is your doctor (in SF Bay Area by chance?). Can you give names of websites where I can read about this? Thank you.
Iron absorption is probably affected. This could be a gut thing or a metabolic thing, including possible transferrin problems. Its also conceivable that high demand by bacteria in the gut, or even chronic bacterial infection, could cause low iron. Finally its possible that weak gut integrity leads to increased loss of blood and hence iron. Higher than normal blood loss from any cause would be a risk factor.
Low ferritin does not preclude higher iron levels, due to other mechanisms, but its rare, and in any case this would result in an inability to properly transfer the iron, making it unavailable.
Any search for high ferritin should bring up a list of other causes.
IMPCC has one example of listed causes in their article on high ferritin. Cort, can I post a direct link here?
Please do post a link Alex. They are always welcome 🙂
http://highferritin.imppc.org/hiperferritin.php?lang=en
The link I mentioned showing many causes of high ferritin. There are a lot over the web, and the one I most recall ranked causes in incidence order, but I have not found it again, yet.
Thank you, Alex 🙂
I’m also a hemochromatosis gene carrier with low iron & folate. (And ME 22 years) I only seem to absorb iron called spatone. I was on iron tablets and then floravital every day and it did nothing but deplete me. Spatone with vitamin C I seem to absorb better according to my blood results. It’s welsh mountain water with natural iron in. Also I discovered the NHS folate tablets made me very ill & did nothing, but Swanson L methyl folate worked wonders. (But depleted my iron & B12). So it seems I have to take melylated B vitamins Spatone & vitamin C to absorb anything. So I think it’s a metabolic issue & type of mineral is important. Someone on Facebook told me iron & b vitamins work synergistically so need to be taken together & to check iron & B12 if taking folate only & lo and behold she was correct which amazed both me and my Dr. I tested negative for the mfthr methylation gene when I looked so it could be an ME acquired metabolic dysfunction? I was doing well and got lazy taking supplements and I’m iron deficient again. So even though I have a healthy diet I don’t seem to be able to get enough vitamins and need to supplement so it’s likely an absorption issue at play as well
PS I want to clarify that I did not mean that people with OI are likely to suffer from alcoholism, but that alcohol and OI are a bad mix.
That’s for sure 🙂
Extremely interest post thanks Cort.
I like the term “heterogenous condition”.
There is so much being discussed here in the context of POTs, that fits with my own experiences with FM, that I am sure some of the heterogenous factors are shared between these conditions and with CFS.
For example, I strongly believe that deconditioning makes FM worse, or rather, makes one prone to worsened symptoms from lesser and lesser exertions, as one loses condition from exertion avoidance. Is this true of CFS as well?
But missing from the findings being discussed here, is the possibility that the intensity of remedial exercise needs to be fine-tuned for each patient. My own experience with FM for 20 fruitless years, was one of constant post-exercise pain and tension and stiffness as a result of the intensity always being too high. But the fact that I kept it up (mostly) may have saved me from the deconditioning-related decline experienced by many.
And I also like this assessment:
“…It’s important to note that POTS is more than deconditioning. Problems with the blood vessels, blood volume or sympathetic nervous system functioning also abound…”
Same with FM and probably CFS as well. The actual physical dysfunctions are the cause of the exertion avoidance that leads to the deconditioning. Victims are not especially lazy or wimps. I went down with FM when I was a competitive cyclist and following a dedicated training regime with lots of miles.
I am sure that dysfunction in blood flows and / or vasoconstriction explain a lot about my FM experiences. I have surmised that this may be simply due to blood vessels and lymph vessels being trapped and squashed in “stuck” and knotted muscle fibre and myofascia. But there may be more going on, which is why I have often referred to “POTs-type symptoms”. I have retained the ability to cycle quite briskly but walking is ridiculously wearying. I could do a seated leg-press of 2.5 times my own body weight even though I couldn’t simply squat down (I have regained the ability to squat and a lot more now with my discoveries of efficacious self-help regimes).
But FM’s heterogeneity may mean that some people with it, actually don’t have the myofascia dysfunctions that are an inherent factor with me. Maybe some people with POTs (but without an FM diagnosis as well as yet), have the stuck and knotted muscle tissue? I agree with Devin Starlanyl, that this is due to myofascial “ground substance” losing its lubricity.
I very much doubt that anyone with this myofascia dysfunction, does not also have the symptoms that qualify them for an FM diagnosis, and I also believe they will have blood flow problems.
I just believe that blood flow problems are part an parcel of both illnesses.
It’s interesting that you do better at exercises that don’t require you to be upright such as bicycling and leg presses as opposed to walking and squats.
Phillip that is very interesting. I have POTS and my mom has FM/CFS in extreme and has the stuck tissues. I suspect i do as well and ive always since a child had painful skin in fatty areas. What do you do for the fascia to get it unstuck?
Hi Cort, interesting article but I think you may of made a mistake right at the start
“POTS is a condition characterized by very rapid heart rates (>40 bpm increase – adolescents; 30 bpm increase – adults) and loss of blood to the lower body while standing”
Isnt the blood loss to the brain? as the lower body has the blood pooling so there shouldnt be a loss of blood to the lower body
Whoopsie! Just the opposite of what I intended! Thanks for catching that..I am fixing right now.
Nitric oxide can cause dilation of blood vessels so conceivable that some POTS might have high nitric oxide. It is not hard to study Nitric oxide in exhaled breath. Has anyone looked at exhaled Nitric oxide (NO) for POTs vs ME/CFS or ME?CFS w POTS? ME/CFS keeps mentioning nitrosation issues. NO can also bind to haemoglobin, and thus perhaps affect its oxygen carrying ability or releasing ability. Any careful studies done for NO/ and ME. NO also affects nervous system. 20-30 ppbv exhaled NO is typical for normal people, and FDA approved exhaled NO test, low cost, for asthma management, so would love to see a patient center study exhaled breath nitric oxide. Aerocrine, makes NO meter, and perhaps also Siemens etc. Need some studies, unless any already done, I suggest.
Another cause of POTS is Mast Cell Activation, according to our cardiologist, which makes some of the mentioned medications for POTS – like beta-blockers – cause severe adverse reactions. There is apparently a subset of ME/CFS patients with POTS, MSAS and EDS according to several doctors.
Agreed!
I was diagnosed with Neurocardiogenic Syncope by a cardiologist. He explained it as a lack of communication between the brain and heart as a result of the blood pooling in the legs. I was diagnosed not through any testing but by an apparently classic textbook description of my symptoms, which were racing heart, faintness/weakness, cold and clammy yet sweaty, all upon standing still for more than a couple of minutes, whether it be in my own home or in line at the store checkout line, waiting at the deli or comparing labels/prices on products. I was prescribed a beta blocker which has reduced the sensation of the racing heart but I still get the other symptoms and actually have overall increased fatigue. The condition has created a fear of shopping, which is a rare feat in itself due to fatigue, but now especially coupled with a fear of getting stuck in a line. A panic sets in making the condition truly life altering
I forgot to mention that when I get the symptoms, I must immediately find a place to sit down (laying is preferred but not always accessible) because I get so extremely weak I can barely stand. The dr says if I didn’t sit I would likely pass out.
My daughter is an RN, and prior to getting the diagnosis, she had a hypothesis that I was experiencing low blood pressure. Once I experienced this at the store and had to sit in my car for quite some time before I had the capacity to drive the one mile home. Once home I was still pretty shaky and she took my blood pressure and it was actually very high.
It could be that your blood pressure was very high when your daughter took it. But you’ve now no way of knowing what it was during the activity. That’s the problem, in my opinion, of blood pressure readings. We take them at a single moment in time, and we take them sitting down. Even if we have a so-called 24 hour test (mine only lasted eleven hours), the readings are taken once an hour. We don’t know what’s happening the rest of that hour. I believe we could learn much more if we could find a way to have a continual BP reading. Imagine if we could have a graph showing the FULL story, and then map that against what we were doing at the time.
My GP was very happy with my eleven hour BP readings as, although the first hour or so were very high, they then settled to a better level. He was happy, that is, until I pointed out that the better readings were all taken while I was lying prone,
Mayo Clinic is in Rochester, MN (not New York).
How many people with POTS are positive for Protomyxzoa also? My excellent LLMD (who was also past President of ACAM) told me that Dr. Fry himself told her that Protomyxzoa clogs veins horribly with long stringy stuff (which occasionally has been pulled out of veins in routine blood draws)–could this be what is actually causing the circulation problems in POTS?
Fort how can I get a hold of you?!?!?! I have been telling my docs something is off on this exercise protocol they have me on and they don’t believe me…I also have CFS and FM and I have been saying that they aren’t taking that into account and they aren’t listening to me…I’m trying to understand exactly what all this means with the brain fog…I would absolutely love to pick your brain!
I was excited by that title that “new” information was included but the only information provided here is from 2004. Many other medical journals and research studies have been done on exercise and Pots. The information is no longer accurate and I’m not sure even Mayo refers to these terms anymore? A lot has been updated on Pots and exercise in the past 13 years.
I don’t know why the information seemed dated; the blog was based on journal articles published in 2014 and 2016.
Cardiac responses to exercise distinguish postural orthostatic tachycardia syndrome variants Paolo T. Pianosi1, Darrell R. Schroeder2 & Philip R. Fischer. Physiol Rep, 4 (22), 2016, e13040, doi: 10.14814/phy2.13040
High flow variant postural orthostatic tachycardia syndrome amplifies the cardiac output response to exercise in adolescents Paolo T. Pianosi, Adele H. Goodloe, David Soma, Ken O. Parker, Chad K. Brands & Philip R. Fischer. Physiol Rep, 2 (8), 2014, e12122, doi: 10.14814/phy2.12122
This information has be debunked by recent studies. The research quoted in the article is from 2004. I’m sorry, but this information is not up to date. You might speak with your cardiologist or contact a Pots specialist about current information from Mayo. I have spent a lot of time researching exercise as a personal trainer.