Wally’s High Blood Pressure Tales: Of Dentists, Wrist Cuffs and an Experiment

Today’s post comes from the Wally, the life coach of the skeptical cardiologist,  who (ultimately) relates what happened when he agreed to do a blood pressure experiment in exchange for medical advice.


Blood Pressure Story 1

I used to work for a company that, for a short time, rewarded healthy employees with lower insurance premiums. They based your score on body-mass-index (BMI), cholesterol, and blood pressure (BP). At the time, I was riding a bike a lot so my BMI was acceptable. My cholesterol was also within range since I take a low dose of a statin. But, my blood pressure? I’ve been doing battle with my blood pressure since the 1980s. So, on the morning of the screening, I took precautions: no alcohol the night before and no coffee before the test. Let’s talk about coffee for a moment: I’m an engineer and we use coffee for fuel. Never hire an engineer who doesn’t drink coffee. In fact, here’s how I interview a new engineering candidate:

Me: “Do you like coffee?”
Candidate: “Yes”
Me: “How do you like it?”
Candidate: “Black.”
Me: “Congratulations, you have the job!”

Back to the morning of the screening: I had no coffee and I may have had low blood sugar. I got in my car and started backing out. It’s 6:30AM and dark outside – backing, backing, backing, CRUNCH. In spite of having a backup camera I still somehow managed to hit my daughter’s car. I’m sure that sent my BP up. Fortunately, I had calmed down enough to pass all of my tests by the time I got to the screening center 30 minutes later. 

Blood Pressure Story 2

On another morning I had to go to the dentist – I always go early so that I don’t miss any work. So, with three cups of coffee in me I hit the road. Of course, I didn’t take traffic into consideration and  I was 10 minutes late. The staff at the dentist’s office didn’t mind but I was a little anxious because 1) I hate to be late and 2) I was at the dentist’s office. 

They have me sit in the adjustable padded chair and ask me the usual questions about changes in the meds I’m taking. While that’s going on, I’m trying to remember if this is the visit where they take X-rays or the visit where they use a needle to evaluate the pliability and travel of my gumline. Trust me, the gumline eval is not fun and as I start to think it’s going to happen, the hygienist puts a small integrated blood pressure cuff on my wrist. Really? You’re about to poke sharp things into my mouth and you’re measuring my BP? Of course, it’s terrible. They measure again: not so terrible. And on the 3rd measurement? Back to terrible.

Ever hear anybody say, “The dentist sure was fun today!” No, you haven’t. That sentence has never been spoken – unless the valve on the nitrous tank was leaking. This guy though, he liked to visit his dentist:

Blood Pressure Story 3

The Beginning

I had a semiannual physical coming up and I realized I better follow my doctor’s advice from my last visit and measure my BP first thing in the morning – before the coffee. Now, I have an old blood pressure cuff that I bought at a garage sale about 20 years ago and it still worked. But I started wondering how accurate it was given its age. So I went shopping on Amazon and decided to buy the same wrist cuff that they use at the demented dentist office. The morning after it came, I measured my BP and… well it wasn’t very good. So, I called my good friend The Skeptical Cardiologist and asked for his advice. And he graciously agreed to help – for a price. We made a deal: he would guide me on my journey to a lower BP. In exchange I would collect some data and provide an opinion on the different cuffs.

In other words: I volunteered to be the SC’s Lab Rat. At first I was proud that he was considering me to provide invaluable data. But, as time went on, I started thinking this might have been his revenge for a laboratory mishap that I caused when we were undergrads. Anyway, on to the experiment!

The Equipment

LifeSource UA-767

Your basic brachial BP cuff purchased at a garage sale.

OMRON 3 Series Wrist Blood Pressure Monitor

New. Can save data to your phone via bluetooth. Small.

The Protocol

First thing in the morning:

  1. Take three measurements on the left wrist with the Omron
  2. Take three measurements on the left arm with the LifeSource
  3. Take three measurements on the right wrist with the Omron
  4. Take three measurements on the right arm with the LifeSource

The Data

I’m a lousy scientist. I started off with good intentions but pretty soon, I started forgetting the evening measurements. And then, when I saw that there wasn’t too much deviation between the measurements on my left and right arms, I only made left arm measurements.

Here are the first two days of data:

January 1st:

The BP measured on my right side was lower in the morning and higher with the wrist cuff in the evening.

January 2nd:

On the 2nd day, left and right were more consistent but the wrist cuff was higher in the evening. About this time, I was already getting annoyed with the wrist cuff and decided to return it. My reasons for this are detailed below. 

I continued to measure my BP in the mornings using just the LifeSource cuff:

Other than the data from 1/5/20, there appears to be reasonably good correlation between the left and right arms.

Note the 12 day gap between the last two data sets. That’s because:

Tragedy Strikes

On the morning of January 8th, the LifeSource UA-767 blood pressure cuff crashed and burned on my kitchen table. The root cause of the failure was a small molded rubber doohickey that acted as an attachment point for the air system in the meter. I now had no means of measuring my BP. The experiment was over.

Review and Wrap Up

First of all this was not a very scientific experiment. By changing my meds I was able to get my BP down but I failed to collect all the data that the SC asked for. The reasons for this were 1) I returned the Omron wrist cuff early, 2) I kept forgetting to take my BP in the evening (it was a little crazy at my house over the holidays), and 3) the LifeSource died.  But I had used both instruments long enough to form an opinion:

Omron

I had high hopes for the Omron wrist cuff – it was new, and it was small with none of the awkwardness of the more traditional brachial style cuff. But I quickly started finding flaws:

  1. A wrist cuff has to be carefully positioned to get accurate measurements. While Omron says that the edge of the strap should be 1/2” away from the bottom of your palm, I had better luck just centering the strap over the vein where your radial pulse is measured. And besides, exactly where is the bottom of my palm? I could see where that would confuse some people.
  2. I found that manipulating the strap on the wrist cuff with one hand to be a little more difficult than the brachial cuff. Now maybe if I had kept it longer I would have become more adept but right away I felt that this could also lead to some positioning errors.
  3. To make accurate measurements with the Omron requires that you elevate your wrist to the same height as your heart. You can do this one of two ways: 1) physically hold up your wrist for the duration of the measurement or 2) prop it up with a pillow. This step is not required with an arm cuff because once applied it’s already positioned at roughly the same height as your heart. 
  4. Home blood pressure monitors have small air pumps in them to pressurize the cuff – that’s the buzzing sound you hear when you press the Start button. Since the enclosure for the Omron monitor is smaller than the LifeSource device, it has to use a smaller air pump. And a smaller air pump needs more time to pressurize the cuff. So you have to sit there and hold up your wrist while waiting for the cuff to pressurize – I found this a little tiring.

On the plus side the Omron did come with a small plastic case and didn’t take up too much space. And it had Bluetooth which allowed me to save my measurements on my phone using their app.  

LifeSource

The LifeSource was a boring old fashioned BP Meter that got the job done – until it died. My only complaint about these devices is that they’re awkward to store. There’s the cuff, the base, and the rubber tube connecting the two. Combined these things always get tangled up with other stuff.

Conclusions 

The old fashioned arm cuff is the way to go based on my experience. Yes, they’re awkward but they are solid and less prone to error. Because of this, I replaced the LifeSource with an Omron arm cuff monitor. And for storage I also bought a small enclosure for it.  And as for my BP, I was able to get it down in time for my doctor’s appointment.


When Wally is not creating laboratory mishaps or providing life coach consulting he dabbles in electrical engineering, tells mysteriously hilarious jokes,  and runs a website called Pi-Plates.com.

We met our freshman year at Oklahoma University and Jerry claims my first words to him were “Are you ready for the country?”

Skeptically Yours,

-ACP

8 thoughts on “Wally’s High Blood Pressure Tales: Of Dentists, Wrist Cuffs and an Experiment”

  1. The author is very interesting andentertaining. It is important to know what you’re doing in order to get accurate information. I have successfully been using verified Omron wrist blood pressure cuffs in the care of my patients are somewhere between 10 and 20 years.

  2. The life coach here is an excellent writer. When you don’t know what you’re doing, it’s hard to get right information. I have been using verified accurate Omron wrist blood pressure cuffs were somewhere around 10-20 years with great accuracy and help in controlling patient’s home blood pressures. As in engineering, it is important to know what you are doing: that is said more with humor than complaint but it is true in any case. See my Journal of Hyperstension articleI am looking at Melania Trump on CNN: holy cow, what a beauty.

  3. I have an Omron series 5 (brachial). I have no idea how accurate it is, but–the second measurement is ALWAYS considerably lower than the first (both systolic and diastolic)–often over 10 mm each.
    BTW, your dentist shouldn’t be using a “needle” as a perio probe (though I admit if you push anything hard enough it’s gonna hurt).

  4. Wally seems like a cool guy!
    3 questions:

    If devices are equal in quality and craftsmanship, brachial pressure should be more accurate than radial because radial is more distal to the heart, is that an accurate belief?

    Since Wally was using two different measurements,do you think its a good idea to measure brachial and radial to assess for PAD ( peripheral artery disease)? Or would it be more accurate to look at pedal and brachial?

    Is there a big difference between the pressure in the cardiac arteries vs the peripheral arteries? I figured there was a correlation between peripheral pressure and cardiac artery pressure but I was unsure since the cardiac arteries are in such close proximity to the ventricular contraction and being fed directly by the ascending aorta.

  5. I have the same Omron wrist monitor and I now prefer it over my cuff monitor because, (1) it is quick and easy to put on (I slip it over the hand onto the wrist and then hold the display unit on my chest to pull and fasten the velcro strap), (2) it is so silent I can measure with nobody around even noticing, (3) it’s footprint is so small I just leave it unobtrusively on my desk. It is slower, but no disadvantage for me because I am already taking time to sit quietly a few minutes (following instructions for correct measurement of blood pressure), so the total time is about the same as the cufff monitor.

    You must have purchased your Omron wrist monitor from a retailer with a good return policy. I learned a lesson to avoid purchasing Omron products directly from their website because the return shipping cost turns out to be the customer’s responsibility. I returned a body composition scale that didn’t work and the return cost was over half the original purchase price.

  6. My blood pressure has always been OK and even slightly low for a 40 year guy.

    However, one day I went to my eye doctor and they used this cheap wrist cuff – 135 / 90!! i blinked and was perplexed. Ok, full confession- i am an engineer and had 3 cups of coffee that morning.

    long story short- went to my PCP and he laughed. He said wrist cuffs are worthless!! the nurse measured my BP and my PCP did too and perfect 110/70.

    anyway, my 2 cents – be careful of dentist and eye doctors measuring BP!!!

    1. Since most people go to the dentist more than their physicians, they really are on point to do a screening. Second, as the OP pointed out just walking into a dentist office can be stress inducing (except mine of course). Have had concerns about the repeatability of BP results and have compared the traditional cuff to the wrist cuff and find them very close. Also the stethoscope technique relies on your own hearing to judge where as the wrist units use a microphone. This will become an issue for you as you get older.

  7. My Omron 7 wrist cuff gives the same results as my Omron EVOLV and is much easier to use. The Omron 7 indicates when the heart level is found automatically so you never have to guess whether the position for taking your BP is correct or not. After comparing the EVOLV with the Omron 7, the only difference I have found is the price. I paid 78 dollars not including tax for the EVOLV while paying a discount price of 36 dollars for the Omron 7 wrist cuff. The only caveat is that I have not been diagnosed with any CVD disease and do not have high blood pressure as confirmed by both the EVOLV and Omron 7. If a person has CHD, PAD or other known risk factors for CVD, then perhaps the EVOLV would give a slightly more accurate reading. In my case the slightly does not exist and Omron 7 is easier to use.

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