Ten Questions Discussion

[ramakentesh]

thanks for all your replies.

The main aim of the ten questions was to see if we could break up POTS based on perceptions of symptoms into the different classifications or Models of primary POTS currently available.

The technical bit: (feel free to skip)

The conjectural ideas for the causes of POTS are pretty much three schools of thought:

1. Primary POTS broken up into two catagories - the primary peripheral dysautonomia variety with accounts for 90% of patients and it relates to a post viral autoimmune response that attacks and damages the nerves that control vasoconstriction in the lower body and - hyperadrenergic POTS caused by faulty reuptake of norepinephrine.

So in one case we have POTS as an appropriate response to an inappropriate vasoconstrictive action and an inappropriate reaction to a normal response in hyper POTS.

2. primary POTS is caused by impaired reuptake of norepinephrine in most cases. So an inappropriate response to a normal process. This is the Norepinephrine transporter model but NE may not be specifically elevated.

3. Primary POTS is broken up into three forms; High flow, Normal flow and Low Flow POTS.

- High Flow POTS are patients that have excessive vasodilation in the legs and arms causing excessive blood pooling. This is believed to be the result of the same autoimmune response outlined at 1 in the partial dysautonomia model.

- Normal Flow POTS is characterised with pooling specifically in the stomach region and excessive vasoconstriction on standing. The conjectural cause for this is an inflammatory process in the stomach releasing excessive amounts of nitric oxide into the veins of the stomach causing pooling.

- Low Flow POTS characterised by reduced leg and arm blood flows, intense vasoconstriction and pallor of skin. Symptoms appear worse after bed rest. The conjectural cause of this model is elevated angiotensin II reducing nitric oxide which is a potent vasodilator. patients may have a lower than normal Body mass index.

It was also hypothesised that EDS III would result in secondary POTS.

Why these models are unclear

There are problems with each of these hypothesis.

Dr Stewart et al found that there was some blood pooling in all varieties of POTS. Why there would be blood pooling if the problem in some patients was purely impaired norepinephrine reuptake is unclear. Too much or excessive norepinephrine could account for the majority of symptoms in POTS patients (excessive constriction of the carotid arteries, heart rate uncoupled from blood pressure regulation) but it does not account for the impaired baroreflex or blood pooling unless we assume that it results in reduced regional flows and blood pooling from that.

Similarly there are holes in all the current models that I could cover.

It seems quite clear that in some of POTS patients the problems are caused by an autoimmune response that damages nerves reducing norepinephrine release and vasoconstriction and simultaneously making the remaining nerves overactive to compensate. This may account for the increased nerve activity that is often higher than would be expected from proper whole body norepinephrine and spillover.

But the cause of POTS in other patients - particularly those described as low flow, overconstrictive or hyperadrenergic is still debated.

What your answers help to suggest:

From your responses we can make the following inferences:

1. Symptomatic profile does not demonstrate the type of POTS that you may have. Whether a person described themselves as a gut pooler, leg Pooler of as an overconstrictor, they still reported similar symptoms.

2. Hyperadrenergic symptoms - symptoms of excessive sympathetic system overactivity were reported in all types - leg poolers, gut poolers or overconstrictive type presentations. Therefore it is probably safe to say that excessive norepinephrine levels can occur either as a primary problem or as a reflex response to impaired vasoconstriction. This was as one doctor suggested to my friend. In other words you may have hyperadrenergic symptoms but not be primary hyperadrenergic.

3. Irritable Bowel Syndrome - there is some suggestion that a certain type of POTS is more associated with IBS. Clearly nearly all patients experience IBS and it isnt at all helpful in suggesting the type of POTS you may have.

4. There was some suggestion that type 3 EDS patients were more likely to experience pooling in the stomach region instead of the legs. Clearly from your input, those people who have EDS III nearly all have mainly blood pooling in their legs.

5. The post-sleep and pale skin questions were not helpful as most people reported these.

6. Low Blood Volume was reported by people whether they had leg pooling, gut pooling or constrictive types of presentations. We expected to find this symptom more in the 'hyper' or Low flow types of POTS. We did find that more people who described symptoms as hyper or Low Flow were more likely to say that they have or suspected they had low blood volume. The lack of testing for blood volume in many people hasnt been helpful with this one.

7. Most people reported that they had mild symptoms before an abrupt onset in all types. However people that had a post-viral onset were mainly leg or stomach poolers.

8. Vasoconstriction of hands was more present in people who described their symptoms as hyperadrenergic or exhibited symptoms more consistent with Low Flow presentations. It was also present in nearly all of the people who described gut pooling. This was consistent with the Normal Flow description but may just be a result of excessive norepinephrine responses.

Conclusion

After discussing thing with my friend this morning after he and I had looked over the results it seems to indicate that there is significant symptom overlap between different causal models of POTS if indeed these models are correct.

In other words symptoms do not demonstrate the type of POTS you have as they appear all to be pretty much the same. leg Poolers can also have an overly reactive hyper symptoms as their sympathetic nervous system starts to compensate for blood pooling.

There were some patterns but these were not remarkably indicative and they are described above.

We hoped this might provide some clear consensus on different models confirmed by specific symptom profiles but this wasnt the case.

There was some differences between people who described themselves as Hyper and described states of overconstriction or Low flow. But their slightly different profiles might be explained because of differing levels of sympathetic activity as a response to the same (impaired blood regulation) problem.

The symptoms we were testing for overlap and I guess this doesnt support the idea that there are different types of POTS.

[Katja]

interesting! too bad there wasn't much of a pattern. I'm always curious exactly what's going on in my case, since I seem to have the odd combination of ANS problems secondary to EDS (with a history of ANS problems in that parent who also has EDS), and ANS problems due to a "moderate" length-dependent autonomic neuropathy (which my doctor suspects may also be somewhat hereditary, but goes back to the other side of my family!).

[runningshoe]

Thank you for doing this!

[Heiferly]

As a patient, I hate saying this because I think (some) doctors tend to take it to an extreme and discount patient experience entirely. But as a person who tends to have a rational mind, I thought I would point out that there is a difference between "signs" and "symptoms" per the medical field. Begrudgingly, I have realized that sometimes my experience of symptoms doesn't correlate neatly with the signs. For example, sometimes I feel as though I am experiencing tachycardia while lying down; the sensation, to the best of my perception, is identical to that which I experience when I go tachy standing still for too long. However, using a blood pressure cuff and continuous heart rate monitor, I have found that what is actually occurring is a widening of my pulse pressure to 50+, whilst my heart rate is stable at a good resting heart rate. Both pounding sensations were interpreted (erroneously) by my brain to be the identical phenomenon. However, once I learned more about stroke volume, pulse pressure, etc., my mind had a different filter through which to perceive the sensation I was having in bed, and now I do perceive the sensation as unique from tachycardia. Is this a trick of the mind, or just learning finer differentiations? What if an explanation for the sensation that were untrue had been put into my head? Wouldn't I have accepted that just as readily, presuming it were as plausible?

I guess what I am saying is that there is probably a margin of error in our responses here because some of the questions ask us to infer which signs of POTS we have from which symptoms we have. As many responses state or imply, actual testing or medical screening for hypovolemia, EDS, Raynaud's phenomenon, etc. has not been performed. I think perhaps one of the most fascinating conclusions you can draw from your questionnaire is that despite having symptoms of these diagnoses, POTS patients are routinely bypassed when it comes to actually being tested/diagnosed for these conditions.

One thing that you didn't ask, which I would like to see people answer, is how many people have had one (or more) of their doctors give them a classification for their POTS. My doc never even mentioned the different types of POTS to me, and I honestly don't even know if he's aware of them.

[morgan617]

This is just beyond me, all these phrases wern't used when I started here, and then I was gone for a bit. It was OI and POTS and little more. It's too much for my foggy mountain brain. Although I have always believed none of us fit into any one box and we all overlap. morgan

[ramakentesh]

guess what I am saying is that there is probably a margin of error in our responses here because some of the questions ask us to infer which signs of POTS we have from which symptoms we have. As many responses state or imply, actual testing or medical screening for hypovolemia, EDS, Raynaud's phenomenon, etc. has not been performed. I think perhaps one of the most fascinating conclusions you can draw from your questionnaire is that despite having symptoms of these diagnoses, POTS patients are routinely bypassed when it comes to actually being tested/diagnosed for these conditions.

One thing that you didn't ask, which I would like to see people answer, is how many people have had one (or more) of their doctors give them a classification for their POTS. My doc never even mentioned the different types of POTS to me, and I honestly don't even know if he's aware of them.

I get your point and you are completely right. I never suggested that the exercise didnt have obvious and sufficient problems - perceptions do not equate to facts. What we should have done is ask specific questions that could not be as easily interpreted. Questions about obvious facts. But even if these is some interpretation involved, if enough patients responded and there may still be a suggestive pattern that might be helpful.

As for the types of POTS - most doctors tell me that at this stage they are irrelevant because treatment protocols are the same. What Ive been told by three different POTS specialists and what I think we have proven with this study is that you cannot differentiate a person as hyperadrenergic rather than a blood pooler based on their perception of hyperadrenergic symptoms, because all forms of POTS can present with the same level of sympo-excitation/ANS overstimulation, whether it is the primary cause or secondary to blood pooling. So most people who have been told they are hyperadrenergic simply means that they are presenting with sympo-excitation as a symptom and this does not mean that they have norepinephrine disfunction.

The similarities of symptoms described was a bit of a surprise I thought. Again this doesnt really highlight any significance to the break up of POTS into different models as treatments are all still symptomatic.

My friend wants to write better questions and then see if its more telling later in the week.

[gwensvilla]

looking forward to his questions...its nice someone (read anyone) has an interest....

perceptions can be amazingly different person to person,and sadly many drs dont either do the tests or tell the results..leaving a gap in the patients knowledge.

you would really have thought a researcher who had access to this site would be sitting on a HUGE pool of knowledge...and dare I say even volunteers/guinea pigs!!!!! The answers are here ...waiting for them!!!! Finding the cause would help find the cure.. but I guess until then the treating the symptoms will have to do...and its sad that people even struggle to get to that point...Gwen

guess what I am saying is that there is probably a margin of error in our responses here because some of the questions ask us to infer which signs of POTS we have from which symptoms we have. As many responses state or imply, actual testing or medical screening for hypovolemia, EDS, Raynaud's phenomenon, etc. has not been performed. I think perhaps one of the most fascinating conclusions you can draw from your questionnaire is that despite having symptoms of these diagnoses, POTS patients are routinely bypassed when it comes to actually being tested/diagnosed for these conditions.

One thing that you didn't ask, which I would like to see people answer, is how many people have had one (or more) of their doctors give them a classification for their POTS. My doc never even mentioned the different types of POTS to me, and I honestly don't even know if he's aware of them.

I get your point and you are completely right. I never suggested that the exercise didnt have obvious and sufficient problems - perceptions do not equate to facts. What we should have done is ask specific questions that could not be as easily interpreted. Questions about obvious facts. But even if these is some interpretation involved, if enough patients responded and there may still be a suggestive pattern that might be helpful.

As for the types of POTS - most doctors tell me that at this stage they are irrelevant because treatment protocols are the same. What Ive been told by three different POTS specialists and what I think we have proven with this study is that you cannot differentiate a person as hyperadrenergic rather than a blood pooler based on their perception of hyperadrenergic symptoms, because all forms of POTS can present with the same level of sympo-excitation/ANS overstimulation, whether it is the primary cause or secondary to blood pooling. So most people who have been told they are hyperadrenergic simply means that they are presenting with sympo-excitation as a symptom and this does not mean that they have norepinephrine disfunction.

The similarities of symptoms described was a bit of a surprise I thought. Again this doesnt really highlight any significance to the break up of POTS into different models as treatments are all still symptomatic.

My friend wants to write better questions and then see if its more telling later in the week.