heart

[Babslynn]

What causes my blood pressure to drop low...like 98/53 I have always had a slow heart beat in the 50's..This has just started over the last few months.

[ed34]

I've always believed the manufactures should get their act together on this one, they could save a lot of time from Doctors and give more convenience to patients. Have local stores hold a calibration unit, which is connected to your monitor via the air tube. If could pump known pressures into the home unit allowing it to self calibrate. Only one unit would require regular calibrations then, as opposed to several, and a small fee could be charged.
So if anyone wants to sell the idea, go ahead, I'll take 10% :D

[kenkeith]

Probably the biggest problem is a low battery.  A low voltage will  decrease the current and as expected that would affect the reading and produce an error. That may be the advantage of a good unit over a cheaper model. It seems a good bp unit would have fail safe features that actually can discern any problems and produce an error.

[ed34]

I don't think the cuff is so much the problem as long as the patient puts it in the correct orientation so the sensor is directly over the artery, or pretty close to it. I have seen portable units with tiny holes in the air tube, they also can get loose over time where they connect to the cuff, cheaper models simply have the air tube pushed on. I'm not sure about a time interval, I think the adjustment is simply to have the pressure present itself with a correct voltage which in turn can be turned into an accurate pressure reading (transducer function).
Obviously if the cuff sensor isn't aligned with the artery enough, it will never detect the blood flow has been cut off. I've been caught with this before now, in rehab I was sitting there with a very blue arm all because I hadn't had it explained to me. I had the sensor on the top, not even touching my arm. I wondered why it was blowing up like a zeppelin, I'm surprised I didn't float away.

[kenkeith]

Can't disagree with that.  Thanks for the information.  I do know the public units are unreliable as the cuffs are stretched out of shape by people who may have a heavy jacket on and try an get a reading, etc. Something funny do you remember telling an OP to take the public blood pressure unit to the doctor's office to be compared?   I do have a good memory :)...,

I suppose the adjustment would be with a valve to adjust a jet stream correlated to a specific time interval, etc.  I doubt if a well taken care of a cuff would present much of a problem though. I've had mine for more than 6 years and no problem and there is no calibration needed.  

[ed34]

"is there moving parts"

Of course there are. First how would you get air into the cuff with no moving parts? Second, there is usually a transducer which has a diaphram and this converts pressure into an electrical signal, usually analogue. As the diaphram wears, the pressure reading will be less accurate. All hospital blood pressure monitors are re-callibrated on a regular basis.

[kenkeith]

Also, any one reading can be correct, but it is the totality of averaging the readings that provides a more realistic BP. I have a blood pressure unit that I took to the doctor's office and compared with the doctor's BP unit.  

The question the OP asked was what could cause low blood pressure!  Not whether or not there is a probability the bp unit is inaccurate. Frankly, I believe we all know the bp readings can be inaccurate...even the doctor's bp.  Not aware of any calibration...is there moving parts

[RadioAstronomyObserver]

QUOTE/If you are using a home monitoring system that could also be why the reading is so low because there is a huge margin of error with them unless the systems are calibrated on an annual basis./QUOTE by babslynn

  I have an automatic BP cuff that uses batteries or an AC/DC adapter. Using batteries, for the first two or more uses it's relatively accurate.  After that it reads the pulse accurately but the BP starts running lower and lower.  I just hooked up the ac adapter and it's reading what I would expect it to read, something closer to what my PCP and Cardiologist read the day before.

  So, She is right, the home monitoring stuff can not be counted on as accurate all of the time.

[kenkeith]

Hi Babslynn,

Ruling out a throid problem, etc. Are you taking any medication? That is a frequent reason for low blood pressure. And any condition that reduces the volume of blood pumped into system circulation.

Worst case scenarios: Weakened heart muscle can reduce the amount of blood it pumps. A common cause of weakened heart muscle is a single, large heart attack or repeated smaller heart attacks (a heart attack doesn't always have symptoms) . Also,  conditions that can weaken the ability of the heart to pump blood include medications that are toxic to the heart, infections of the muscle of the heart by viruses and diseases of the heart's valves such as aortic stenosis. You haven't provided any health history or symptoms so there isn't any way to correlate just a low heart rate and blood pressure with any probabilty for a heart condtion.

Pericarditis is an inflammation of the pericardium (the sac surrounding the heart) and that could reduce the cardiac output

There can be pulmonary embolism (clot) in a vessel where a blood clot breaks off and travels to the heart and eventually the lung. Or a large blood clot can block the flow of blood into the pumping chamber (left ventricle) from the lungs and severely diminish the blood returning to the heart for pumping.

You should have those conditions ruled out by your doctor. Thanks for your question, and if you have any further questions or comments you are welcome to respond.  Take care.

[cindy707]

Could be anything but its not really an alarming low b/p or hypotension by the rules of the game.  Being relaxed believe it or not could cause a low b/p and w. a heart rate so low i assume that you are probably in good physical shape.  Unless you are having issues w. the low blood pressure specifically dizziness i really wouldn't be too concerned about it.  If you are using a home monitoring system that could also be why the reading is so low because there is a huge margin of error with them unless the systems are calibrated on an annual basis.  If that is what you are using one of the easiest ways to test the accuracy is to either go to your docs office and bring the monitor w. you and have them test you and then use your monitor right after and see if the readings are the same if so great if not toss it out.  Or you can even go to your local drug store where they have the free machines by the pharmacy and do the same thing to test the accuracy because those machines from my understanding are calibrated every 6 to 12 months......