I have spoken recently how I am on month 3 of an 'adapted PoTS exercise protocol' to help manage my PoTS symptoms. This is part 1 sharing the research and evidence I found to why exercise can help!
Firstly, what is PoTS?
PoTS = Postural Tachycardia Syndrome
"Postural tachycardia syndrome is an abnormality of the functioning of the autonomic (involuntary) nervous system.
To be diagnosed with PoTS, an individual must experience a group of symptoms in the upright position (usually standing) that are relieved by lying down. A persistent increase in heart rate of 30 beats per minute (40 bpm if under 19 years of age) should be recorded within ten minutes of standing.
The autonomic nervous system (ANS) is in charge of all bodily functions that we don’t have to think about, such as heart rate and blood pressure regulation, digestion, bladder control, sweating and stress response. The sympathetic nervous system is part of the autonomic nervous system. It produces the ‘fight or flight’ or ‘stress’ response. When activated, a chemical called norepinephrine is released. Amongst other things, this causes an increase in heart rate and blood pressure." (PoTS, UK)
What causes PoTS?
At the moment they aren't fully sure as there are a number of different factors and associated conditions. They do know that PoTS is often reported in response so a trauma to the body such as a virus or acute stressor such as surgery and being deconditioned. It's also strongly linked with conditions such as EDS (Ehlers Danlos Syndrome), MCAS (Mast Cell Activation Disorder) and ME/CFS (Myalgic Encephalomyelitis/Chronic Fatigue Syndrome). Recent research by Blitchteyn et al (2015) show that PoTS may be another type of an autoimmune disorder and 1 in 5 people with PoTS have a co-morbid autoimmune condition.
How is exercise meant to help?
Often people with PoTS are deconditioned (loss of fitness, muscle strength etc) and have poor exercise tolerance. This is either because of the reason why they developed PoTS i.e. other conditions, stress on the body leading them to become deconditioned, or because PoTS symptoms have lead them to be less active or bed bound in some cases.
Exercise is meant to help in two ways. Cardio training (exercises that work your cardiovascular system) can help improve your stroke volume and blood volume which can help with symptoms of low blood pressure. It also helps increase your hearts muscle mass, particularly in your left ventricle which is needed to pump blood around the body. It helps re-educate your body to when it needs to increase heart rate (activity) and decrease heart rate (rest). Strength training is thought to help improve blood return from your legs to reduce blood pooling. (Heart Rhythm Society, 2015)
What does the research say?
I'm going to get a bit research heavy as I share some of the leading studies which have shown how exercises can help treat and in some causes 'cure' PoTS. I find it really interesting and as a physiotherapist I'd always work with 'evidence based' treatments so before I started anything I did a lot of reading! I'll try to summarise as much as I can.
1. Soldiers Endurance Training
The first study looking at exercise with dysautonomia (when autonomic system does not work properly) was by Winker et al (2005). They screened at 2768 Austrian soldiers for orthostatic tolerance (symptoms bought on by standing) by a questionnaire, and then through tilt testing identified 36 cases with orthostatic intolerance. 31 of these entered the randomised controlled trial, allocated at random to the training group (3 months jogging) or a control group (no endurance training).
Results showed that in the training group, 10 out of the 16 men showed no symptoms of orthostatic intolerance on their tilt table test. Compared to only 1 out of 11 from the control group who did not do the endurance training. This suggested that an endurance training program should be considered in treating orthostatic tolerance.
However, results are limited as none of the participants had a clinical diagnosis of PoTS, they were clinically healthy to be in the army. It was a small group and it was all men, which PoTS is typically seen more in females.
2. Professor Benjamin Levine
Professor Levine was a US cardiologist, working with astronauts at NASA that led him to research exercise and PoTS. In zero gravity, the astronauts heart becomes deconditioned and shrinks, losing heart muscle mass, especially in the left ventricle. He designed a horizontal exercise program to help them recover. He says "Endurance exercise (repetitive use of large muscle groups) is what is needed to make the heart increase in size". He believed this approach could they help people with PoTS.
"PoTS is fundamentally a problem of gravity. Two out of three astronauts can’t stand up after they’ve spent even a short time in space, and all of them have very high heart rates when they attempt to stand. This observation got us thinking whether there might be common threads between the adaptation to spaceflight and patients with PoTS”
“The archetypal PoTS patient is someone who is quite high functioning – in some cases, even a competitive athlete or a dancer. Then something happens – it could be an injury or an illness – but it puts them to bed. When they recover from whatever put them to bed, they find they get symptoms such as a high heart rate and dizziness when they stand up. They lie down again because standing is so symptomatic, but that only makes matters worse. It’s a downward spiral”
3. Dallas PoTS Studies (2010-2015)
Over the next few years Levine recruited 54 participants with PoTS. Of this, 27 participated in a 3 month program doing 3-5 sessions of 30-45 min endurance training plus strength training twice a week. The first 4-6 weeks of training were only sitting or horizontal activities, and included upright exercises after this. Participants also had to drink 3L water a day, eat 7-10g salt and elevate bed head by 10-15cm. They had two control groups, one with medication to treat PoTS and one with placebo medication.
Only 19 (76%) managed to complete the program but all 19 showed improvement on physical function scores from the health questionnaire. Compared to the two control groups which did not have improved scores. The exercise group also shows on average heart rate increase of 22bpm on ten minute stand test vs. before the programme the average heart rate increase was 36bpm. After the exercise training, 10 of the 19 no longer met the criteria for PoTS and were in remission. (Levine et al, 2011) (Shibata et al 2012)
4. International Registry Study (2016
Following the success of the Dallas study, the next big study was to try to test the exercise program in the community without Levine's supervision. They enrolled 251 patients (86% women) through their physicians. A 3-month program involving mild- to moderate-intensity endurance training (progressing from semi-recumbent to upright, 3-5 times/wk, 30-45 min/session) plus strength training was implemented along with increasing salt/water intake. The program was delivered to the physicians, who oversaw training in their patients. A 10-minute stand test was performed at the physician's office and patient quality of life was assessed using a questionnaire.
One hundred and three patients completed the program. Of those that completed, 71% no longer qualified for PoTS and were in remission. It showed that this exercise/lifestyle intervention could be used in the community setting and was effective in treating PoTS. (Levine et al, 2016)
5. Exercise and non-pharmacological treatment of POTs
A recent study by Levine et al (2018) built upon his research by adding that exercising training should be implemented as early as possible for patients diagnosed with PoTS. A supervised program is needed to ensure that patients use horizontal training first, and then as their fitness improves, then the duration and intensity can be gradually increased as well as transitioning to upright exercise as tolerated. It also adds that other other non-pharmacological interventions should be used which include:
chronic volume expansion via sleeping in the head-up position
reduction in venous pooling during orthostasis by lower body compression garments
physical countermeasure maneuvers, such as squeezing a rubber ball, leg crossing, muscle pumping, squatting, negative-pressure breathing, etc., may also be effective in preventing orthostatic intolerance and managing acute clinical symptoms in PoTS patients
Limitations of Research
So far although great progress has been made in the last ten years, the studies still have many limitations and more research needs to be done.
Most of the trials have a small number of people in both the control and treatment groups, we need to see what would happen in larger sample sizes. One of the limitations in recruiting patients for trials is that many of the trials are self selected, in that people volunteer to take part. Those that are bed or wheelchair bound may be unable to carry out exercise training program at the intensity required for the studies. The amount of time and energy too may put some people off or they may not comply fully with the program.
PoTS is regularly associated with other conditions yet no research has been done on how this affects the exercise regime. In fact some of the studies did not include people with EDS in their results. It may be the exercise regime is not accessible for people with EDS or associated bladder and bowel issues.
We do not know the long-term effects on using this exercise protocol, how soon do symptoms return if you stop? Can you progress to managing symptoms with generic exercise? Plus the exact exercises and training techniques could do with more research to work out the most effective training method.
Lots more research is needed but studies such as PULSE (2019-2022) are "assessing supervised exercise rehabilitation intervention with behavioural and motivational support, compared to usual care, for people with PoTS". So hopefully in the next few years we will be able to fill in more gaps in our knowledge and even get exercise rehab for PoTS included in our treatment plans!
Conclusion
It's up to you what you take from the above research, but I believe despite the limitations of some of the studies it shows there is clearly a benefit to exercising with PoTS. Although some medication can improve peoples quality of life, nothing seems to compare to the improvement exercise can bring - plus the side effects of exercise are normally a lot nicer to deal with! I think fitting exercise into your 'tool box' of management techniques for PoTS would be helpful for most people.
If you are encouraged by these positive results - next week I will share the adapted Levine protocol I have been following along with all the information you need before you get started!
Lots of love, Zoe xx
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