Measuring Blood Pressure

[Mick F]

A year or more ago, I stood up after lounging on the settee feet up in a "somnambulant posture" and went into the bathroom. (we live in a bungalow). Next thing I know, Mrs Mick F is standing over me and I'm lying down with the back of my head cut and bleeding. She'd heard a thump. I'd obviously fallen backwards onto the hard tiled floor.

Why?
I'd fainted, probably due to low blood pressure.
This seems strange when you consider I generally have BP on the high side!

This goes back to what axel_knutt is suggesting, that someone's high BP is another man's normal.

[531colin]

Exactly what I've found. I remember a programme on tv that went into it. Think it had interviews with researchers in the field of hypotension. It said more and more research from around the world was gaining momentum in acceptance that there is evidence of links between many serious conditions and hypotension. Sure it was dementia and something like strokes.

To quote Humpty Dumpty in "Alice".......anything I say means exactly what I mean it to mean at the time, nothing more, and certainly nothing less........
....if you google hypotension/stroke/dementia and don't get any authoritative hits then there is nothing published and its all TV journalists looking for a story or snake oil salesmen.
Sure if a dementia patient experiences hypotension, their dementia is likely to appear worse......just like it does if they become dehydrated, for example.
If you have a narrowed artery in your brain and your pressure crashes, I guess that could precipitate a stroke....high BP precipitates strokes in patients with atheroma or aneurysm. Blood clots cause strokes.
I used to work with an irish vet who had a saying,,,,,,"if you are in County Cork and you hear hoof falls on the road, don't go looking for zebra....."
....in other words, common things occur commonly. Only when you have worked through the common things should you start looking for the rarities.

[531colin]

A year or more ago, I stood up after lounging on the settee feet up in a "somnambulant posture" and went into the bathroom. (we live in a bungalow). Next thing I know, Mrs Mick F is standing over me and I'm lying down with the back of my head cut and bleeding. She'd heard a thump. I'd obviously fallen backwards onto the hard tiled floor.

Why?
I'd fainted, probably due to low blood pressure.
This seems strange when you consider I generally have BP on the high side!

This goes back to what axel_knutt is suggesting, that someone's high BP is another man's normal.

Mick, its orthostatic or postural hypotension. Look it up. Your BP is normal, stop stressing about it.

[Mick F]

....................... stop stressing about it.

Stress?
I've suffered from it all my life. It's part of me, and it's who I am. "Suffered" is not really the right word, maybe it should be "experienced".

Thanks Colin. I have really appreciated your comments and the way you've put it across.

Thanks.

[Paulatic]

A year or more ago, I stood up after lounging on the settee feet up in a "somnambulant posture" and went into the bathroom. (we live in a bungalow). Next thing I know, Mrs Mick F is standing over me and I'm lying down with the back of my head cut and bleeding. She'd heard a thump. I'd obviously fallen backwards onto the hard tiled floor.

Why?
I'd fainted, probably due to low blood pressure.
This seems strange when you consider I generally have BP on the high side!
.

Could the feinting not be due to a low heart rate (bradycardia) ?
I'm troubled all the time with it when standing up. Usually get a few paces before I'm hanging onto something to stop myself falling over. My HR is particularly low at the moment resting HR 40 on waking. Sitting here just now after an hours walk and a mug of coffee it is 46.
Whenever I mention this on rare visits to doctors they say I'm a "trained athlete" I reply I just ride a bike.

[axel_knutt]

A patient in AF will have a different "pressure" for every heartbeat

Something that puzzles me though, is that although I sometimes get a feeling that the room has done a quick pirouette when I drop one odd heartbeat, I don't get the same when my heart stops altogether for five or six seconds.

Exactly what I've found. I remember a programme on tv that went into it. Think it had interviews with researchers in the field of hypotension. It said more and more research from around the world was gaining momentum in acceptance that there is evidence of links between many serious conditions and hypotension. Sure it was dementia and something like strokes.

36,00 hits

The results support our clinical impressions that OH and low blood pressure is common and an important factor in organic dementia.
Our findings suggest that cerebral hypoperfusion is not an uncommon mechanism to contribute to the evolution of vascular dementia in the elderly.
Both low diastolic and high systolic pressure are associated with an increased risk of Alzheimer disease and dementia in this elderly population.

Arrhythmia is also a risk factor for dementia, possibly due to low BP, but they've also found a link with poor control of INR (anticoagulation).

Sitting here just now after an hours walk and a mug of coffee it is 46. Whenever I mention this on rare visits to doctors they say I'm a "trained athlete" I reply I just ride a bike.

When I was in hospital last weekend they were fretting over my HR being 46, it was an uphill struggle getting to listen when I was telling them that's my normal RHR. The alarm on the monitor was set at 50, so having that rattling their cage wasn't exactly helping. Sometimes when they're more in the mood for listening they set the alarm to a lower threshold to shut it up.

[531colin]

36,000 hits is nothing.....I just got one and a half million hits for ~"jesus abducted me in a spaceship"

One you linked starts....Among 133 consecutive patients with the clinical diagnosis of vascular dementia there were 6 patients (4.5%) in whom dementia was judged to be associated with cerebral hypoperfusion due to cardiac arrhythmias and systemic hypotension.

Then it jumps to....... Our findings suggest that cerebral hypoperfusion is not an uncommon mechanism to contribute to the evolution of vascular dementia in the elderly.

Sorry, boys, 4.5% is just that......uncommon....and it doesn't establish cause and effect. http://onlinelibrary.wiley.com/doi/10.1111/j.1600-0404.1987.tb03555.x/abstract

I'm sure you know that AF patients risk clots forming, which is why they check INR so closely. Poor control of INR means more clots, and more showers of bits of clot hitting the brain among other organs. If "poor control" of INR was not linked to increased dementia risk then the whole business of controlling clotting and measuring INR would be pointless.

Another one....."The results support our clinical impressions that OH and low blood pressure is common and an important factor in organic dementia.".........this paper contains......" OH/low blood pressure was present in 39–52% of the patients.".....in other words, more than half the dementia patients didn't show hypotension. Again, hardly shows cause. I wonder how many geriatric patients show OH and not dementia?

I have just done 2 days loading stuff in and out of trailers and manning a stall at the York Rally.....long days for this old man, and I haven't been through all 36,000
papers. If you find anything where the numbers are robust, preferably published in a first quality, peer-reviewed journal, then i don't mind having a look.

[axel_knutt]

A patient in AF will have a different "pressure" for every heartbeat, its almost pointless measuring it. Systolic will vary with how a good a "fill" the ventricle had, and how long since the last beat, and how full the last beat was. Diastolic will continue to fall until you get a couple of good full beats reasonably close together.

There's not much evidence of that on my obs charts from last month.

During AF my BP was stable between 135 and 140, but after I reverted back to NSR it was varying from 96 to 145. The "normal" range marked on the obs charts varies depending on which chart you look at, one format has 110-220, another 100-180, and another has no range marked at all.

[Mick F]

Your BP is normal, stop stressing about it.

It just so happens, that I saw the doc on Tuesday regarding my statins and my not taking them etc etc ...............

There's a BP measuring machine in a room and the public are encouraged to use it. As I left the surgery, the doc asked me to take my BP and hand the print-out to the reception lady. This, I duly did.

However, the first measurement was high so I took it again and again plus swapping arms trying to get a better result. Eventually, I selected the best one and handed it in, but it was quite high. 170something over 90something. Can't remember the exact figures.

On Friday, I received a letter asking me to make a "non-urgent" appointment to discuss my high blood pressure!
I'll pop in tomorrow and make a convenient appointment. Meanwhile I'll take my own BP readings and make notes and take them in.

I don't suffer from high BP, I suffer from stress, and taking my BP as a "test" in a health centre stresses me. Taking it in the comfort of my own armchair doesn't.

[MikeF]

I was asked to take my home BP machine to the nurse so that a comparison could be made between "their" machine and mine. I therefore had my BP taken under extremely similar conditions on two machines - one of which was supposed to be accurate ie the one in the doc's surgery. As it turned out my home machine gave BP reading within about 1mm of the doc's one. This is really the only reliable way you can check your machine. I wouldn't rely on that public BP measuring machine for a comparison with yours unless you take your machine and do the test at the same time. Even then that's not as good as a "blind" test by a third party.

We all, I think, tend to worry if our BP is too high and this does tend to raise it when a measurement is being taken, especially at the docs! As you indicate you were already trying to bias the results. I know the feeling, although I do not take statins, but amlodipine tablets. BP generally increases with age, but it also varies with the time of day, exercise, temperature etc. That's why it really needs to be taken at a specific time of day eg when you just get up before breakfast, and have not done much else.

If you measure your BP after a cycle ride of any duration you will no doubt find it much lower than when you are resting a few hours afterwards or before the ride.

[Mick F]

How can you check your home machine against the "calibrated" machine at the health centre?

This is a serious question BTW.

1. I can check my BP on one arm and then immediately on the other, and get different results.

2. I can check my BP and wait ten minutes and take another reading, and it's different. I can repeat that ad infinitum and the readings are different each and every time (both up and down).

3. I could go to the health centre and stick one arm in their machine and fit my home machine on the other arm and start the test simultaneously. I can guarantee that the figures will be different.

4. I could swap the tests over arm-for-arm and do it again, and the figures will be different.

5. I could do that ad infinitum and the figures will be different each and every time.

The only way I can see this being resolved, is to fit two devices to the same arm at the same time.

[MikeF]

How can you check your home machine against the "calibrated" machine at the health centre?

This is a serious question BTW.

1. I can check my BP on one arm and then immediately on the other, and get different results.

2. I can check my BP and wait ten minutes and take another reading, and it's different. I can repeat that ad infinitum and the readings are different each and every time (both up and down).

3. I could go to the health centre and stick one arm in their machine and fit my home machine on the other arm and start the test simultaneously. I can guarantee that the figures will be different.

4. I could swap the tests over arm-for-arm and do it again, and the figures will be different.

5. I could do that ad infinitum and the figures will be different each and every time.

The only way I can see this being resolved, is to fit two devices to the same arm at the same time.

I'm not sure calibrate is the right word, but I was asked to bring my home machine to the docs. BP was taken using first one device (I cannot remember which) and then the other. The results weren't looked at until both readings had been taken. I agree this is not perfect and our blood pressure varies slightly from minute to minute. You could of course repeat the checks several times, but you are supposed to wait a few minutes before doing repeat readings. If you aren't then your readings may not be representative. Provided you remain at rest and in the same position and state of relaxation your BP should remain more or less the same. There shouldn't be big variations, say 5mm?? for systolic (high) reading - I don't know how much as I'm not a doctor. How great are the variations in your readings?

The tests should always be done on the same arm - left is usually chosen. Pressure may well be different in different arms as we aren't symmetrical. I don't think the exact figure is that critical it's where it generally lies that seems to matter. However if your BP varies greatly then perhaps you should mention it to the doc, but then I know the problems with that

Of course the only accurate way to check a BP monitor is to have it calibrated by the manufacture. How good a Lidl or Aldi one is I've no idea - maybe that's the problem. The docs always seem to use Omron and that's the make I have.

An option maybe to have a 24hr monitor strapped to you. I think the doc will have to supply this. This device takes readings at random over 24hr including while you're asleep, and presents a much better view of what your BP is doing.

Edit to add I've looked at the readings you posted previously. If the systolic is below 140 you shouldn't have anything to worry about. If it's above 160 at rest then perhaps you should be concerned.

[Psamathe]

How can you check your home machine against the "calibrated" machine at the health centre?

This is a serious question BTW.
...
The only way I can see this being resolved, is to fit two devices to the same arm at the same time. :shock:

I would think there are actually two issues only one of which is checked by comparing a reading with a professional grade machine. I can see how a "built to a price" retail product could suffer from poor calibration and also poor reproducibility.

Comparing a domestic/retail product with a medical grade machine reading an identical pressure would check the calibration (like putting a certified 1Kg weight on a weigh scale and seeing what value it reads).

But to check the reproducibility might be a bit harder. You could take 10 readings of the same pressure and check the variability. But then if poor reproducibility is due to e.g. temperature or maybe humidity, then you'd have to be checking reproducibility over several days/weeks for the same pressure.

And as you (Mick) say, blood pressure is not necessarily "stable" even over a few minutes or arms. I would assume somewhere these companies have a "standard" false arm with a false pulse and false pressure for testing their devices (i.e. one that should give a known calibrated reading).

I have an Omron device. When my GP takes my BP he uses stethoscope and old fashioned hand pump. But the nurse uses what looks like the same machine as I have (same make, same shape, same size, etc.) - which might mean the same company is using the same case and plastic for different quality innards. Or it might mean that in the same way as BMI, blood pressure is more of a general indication of something than an exact measurement. I'm sure years ago I remember being told that if they suspected you of having high BP then the'd give you a longer term recorder for a few days that would continually'ish monitor you through the different levels of activity through the day/night giving a better indication as to there being any real issues. No idea if that was common practice - just what I'd heard.

Ian

[NATURAL ANKLING]

Hi,
I think the lower reading being above 95 is the one to watch.

Any ways.................by BP is affected by exercise as much as 25-30 on the upper level, IF you are on BP meds then expect a severe drop in BP after exercise which normally affect me 1-2 days later........when you get out of chair....I have only ever had light head............And I normally stand still and wait 20 seconds or so closing my eyes too........I can see that passing out could be next.

Low BP means you will live longer for sure, but if it affects you bad then the advise will be not a lot as there is no treatment.

I can only say that get up slower etc, etc,

Sorry Mick F's is not on BP meds...............just get up slower.
H.Rate in the forties....pretty normal for a regular cyclist...................mine drops to high 30's in bed.

But low BP is good and surgery POD test are always high...........nerves............

[Psamathe]

I'm not sure calibrate is the right word, but I was asked to bring my home machine to the docs. BP was taken using first one device (I cannot remember which) and then the other. The results weren't looked at until both readings had been taken. I agree this is not perfect and our blood pressure varies slightly from minute to minute. ....

A year or so ago I had my BP checked professionally (though not at GP practice) and after 1st reading they said "Oh dear ... rather low ... so low we should refer you to your GP ... quite serious actually .... ummmph ...." then the took another reading which was OK and commented " that normally works with low BPs". Basically their scare comments cause you to react part that reaction being increased heart activity and thus increased BP and problem solved. They didn't wait a few minutes and it was significant enough an increase to take me from the "pretty serious" reading to "fine".

Ian