Determining My Pots Sub Type

[andybonse]

Hi guys,

I've been on Midodrine 2.5mg a few weeks now and tried to up the dose to 3.75mg, but as I took my 2nd and 3rd dose, I'd feel weird and dizzy. Not a nice feeling.

So I'm not taking it any more and have an appointment on Monday to discuss this and see what else I can try, pretty let down by it not working, since I have EDS type 3 caused POTS.

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I've been reading on low flow POTS,

My hands, feet, lower legs are always freezing. When I have blood drawn my arm runs out of blood. This tells me there is excessive vasoconstriction of the extremities, in low flow pots this is what happens,

When I get warm/hot my arms vasodilate and blood fills them and I can see my veins stick out.

Now I have this figured out,

I assume either or both of the below is the cause and my body is trying to compensate;

1) Low Systemic Blood Volume

2) Splanchnic Blood Pooling

When the blood fills my arms, or I eat, my heart pounds and goes faster which proves evidence the above points are happening. When I sit up, not stand, I go light headed a minute, so I can only assume a low blood volume is effecting this or the gravity is pulling blood into splanchnic reserves from the thorax and brain.

Now, because Midodrine is causing me to be dizzy and headachy, I can only assume the brain is also more constricted to try keep blood from being pulled down, so therefore Midodrine is actually over vasoconstricting there and less blood is getting perfused.

Now an important point would be, people would call this a hyperadrenic subset, however it has been shown in research NE levels may also be of normal levels.

We could also say hypovelimia would cause low BP, but not necessarily since our bodies can compensate quite well hence the vasoconstriction may be keeping the blood pressure stable, now

My Dystolic blood pressure reading is usually quite low 40-70, now a low blood volume would show this sort of reading, especially when supine.

What do I plan to do:

1) Angeotensin ii and Aldesterone blood tests

2) Autoimmune nuclear antibodies blood tests(ruling out other possible ailments)

3) Mast Cell blood tests due to other symptoms

4) Ideally trail Florinef to expand blood plasma

Please discuss what you think! By the way I am not asking for medical advise, I just want to discuss my theories.

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Andy.

[Chaos]

Not sure if midodrine would be causing cerebral vasoconstriction as it appears that it does not readily cross the blood brain barrier. At such a low dose I wonder how much is actually getting into the brain. I'm not a pharmacist so just throwing things out here as ideas.

Do you only see your veins sticking out when you are warm or do you also notice them when your limbs are in dependent position, i.e. hands are hanging at your sides?

Usually a classical 'hyperadrenergic' POTS patient has high NE levels along with elevated BP upon standing. I'm like you with low BP usually so my POTS specialist says I have "hyper" characteristics but he says "you'd never see these low BPs with a 'true' hyper POTS pt." He thinks the pattern we have may be directly related to how the body is compensating due to the EDS.

From a practical standpoint, I suspect what you'll do is what your physician is willing to try next. Since you're seeing a specialist now he may have his own ideas of how he likes to work thru the options based on what he knows about your case.

[andybonse]

Thanks for your reply Chaos,

The blood brain barrier would not be involved, once Midodrine enters the bloodstream, the alpha a1 receptors are located in the vessels in which Midodrine stimulates and these receptors are in the same vessels which are in the brain.

My veins only stick out when hot and hang by my side, but if normal/cold they don't.

I wonder what my specialist will prescribe next, can only assume Florinef but we will see! Most of my blood pools in the splanchnic vessles but I highly doubt he'll let me trial Octreotide at present.

[jesse1919]

I'm not sure you have excessive vasoconstriction if your diastolic pressure is low. I think that could mean vasodilation. You could have low blood flow in your arms due to blood pooling caused by dilation. If so, then I suppose Midodrine should have helped. Midodrine did make me feel crummy like you described as I increased the dose, but I also could tell I was less lightheaded when I stood and I had more energy. If you want to know if you have low blood volume, you could directly test it. Check out the Daxor system. It cost about $2000 and $600 out of pocket for me. My volume was normal. It might be easier or cheaper just to try Florinef