Wierd Bp

[sj75]

im trying to get my head around why my bp does what it does but am not quite there and wondered if anyone could help. Im on a beta blocker to reduce my pulse but i know they also reduce bp. I find that when my bp comes down my pulse goes up and vice versa. I dont have typical pots as my bp goes up rather than down, i also notice that the gap between readings is very small eg 120/100 and wondered if anyone knows what this may mean?

[Simmy]

Sounds logical. You're brain is constantly attempting to maintain proper blood flow by adjusting heart rate and blood pressure accordingly. A good analogy is a garden hose - if you want the water stream to reach your far-away flower bed (brain) you can accomplish it in one of two ways - either increase the water flow rate (heart rate) or use a thinner hose which increases (blood) pressure. Since the same goal can be accomplished in two distinct ways, the brain recognizes it and when one goes down the other rises to keep what it believes is equilibrium.

Based on a recent poll taken by noodlemaster, it seems that about 40% of us have hypo-pots, 40% hyper-pots and the other 20% no-bp-change-pots, so there is no 'typical' pots and we're all in the same sinking boat.

What you're referring to is called a low pulse pressure (the difference between systolic and diastolic - upper and lower numbers - feed and return). A normal pulse pressure is about 40 (ie. 110/70). When it gets below 20 many become dizzy and some pass out. The lowest I've personally recorded was a 96/82, or a 14pp, which turned my legs into jelly right quick.

[sj75]

thanks so much for that, it makes more sense to me now although i wish the drs would have explained it in the first place. Its just strange to think that the tablets i take (that are also used to lower high bp) make mine higher. Its also nice to know that 40% of potsies have the hyper form as i was led to believe (by my drs) that im unusual in that. I think the Uk has a bit of catching up to do where pots is concerned.x

[Machair]

The difference between the top and bottom readings is very small for me when I stand. Sometimes it can be as low as 85/70. I have always had this since getting sick so you are not alone! Mornings are so much worse before I have had a chance to drink enough.

[flop]

The body is always trying to get more blood to our brains. The cardiovascular system has three ways of increasing BP:

a) making the heart beat faster

making each individual heart beat more forceful (increaseing the volume of blood pumped in each beat)

c) increasing systemic vascular resistance (getting the blood vessels to constrict)

a) and both increase the amount of blood being pumped by the heart

cardiac output = heart rate x stroke volume

cardiac output = a) x

litres/min = beats/min x litres/beat

if only a) and were involved you can see how slowing the heart rate could directly lead to a drop in cardiac output that would usually mean a drop in BP too.

However we mustn't forget about c) the systemic vascular resistance or in other words how constricted or dilated the blood vessels are. In somone with hypotensive POTS the blood vessels tend to be dilated causing low BP. In hyperadrenergic POTS high levels of epinephrine and norepinephrine cause the blood vessels to contract and cause high BP. If only it were quite that simple. There also seem to be some people (like me) who pool blood in the veins but still have high BP. I have never seen this written down but my personal thought is that the veins dilate but the arteries constrict - ie totally messed up!

The one thing that is certain is that the doctors are only beginning to work out the mechanisms and causes of POTS. There are certainly several different processes going on in different people that all give the same symptoms. So POTS is more a group of illnesses rather than one illness. This is why there is no one treatment that works for everyone with POTS - we all respond differently to medications and have to accept the "trial and error" approach to treatment.

I hope I haven't completely befuddled anyone?

Flop

[flop]

Bother, the smilie faces are supposed to be the letter B with ) which just happens to be a short cut to the emoticons.

I also meant to say that narrow pulse pressure can really make you feel awful. My BP is usually high but on my first tilt table test it went to 96/90. My body was constricting all my vessels to keep my diastolic BP high but I was so tachycardic at 170/min that my cardiac output was low. My doctor told me that with only 6mmHg difference in the pressures that there was almost no forwards blood flow happening (I felt awful and was on the verge of passi g out when they put me flat).

Flop

[sj75]

hi flop, thanks for that. Its all starting to make sense now. I dont suppose you know the normal uk results values for the 24 urine collection for hyperadrenergic pots testing? i cant find it anywhere.x

[flop]

Hi SJ,

I don't know the values (one test I haven't had!) but I'll try searching too and see if I can find it.

Flop