|American Heart Association Publishes How To Take Blood Pressure Directions,|
Here is my home cuff reading today
I am forever grateful for the Memorial Hospital ER surgeon who fixed me the night my stretched aorta tore. Thankful also for the St. Vincent's primary care physician I had post surgery who worked with me to understand my number one priority in life was to stay alive.
There have been some great doctors who helped me along recovery's path. To these health care professionals I am grateful for their artisan healing touches.
There too have been many doctors and nurses though who were actually afraid of me. It is so easy to see the lack confidence in a health care professional's face despite their efforts to hide their fear of not knowing what they are dealing with in me. I love them too for they have taught me to be my own best health care advocate.
Lately my systolic blood pressure readings have been quite a bit higher when I visit a medical facility. Aware of 'white coat syndrome' I brushed these anomalies off as just a result of the doctor's office stress. But the 160+ systolic readings the nurses were measuring were disturbing to both them and especially to me with my descending dissection.
Back at home the readings on my arm cuff unit were normal (110/60). My pulse usually hovers around 50 beats per minute or about one per second. My home unit has been previously calibrated.
Either my home blood pressure cuff was incorrectly calibrated or the health care professional's understanding of how to use a stethoscope to obtain a blood pressure reading (auscultation) was flawed.
On the next visit to my primary care my systolic was high again, in the 160s. The stress of wondering why I was being diagnosed with high systolic led to even higher blood pressure readings as my adrenaline kicked in.
What was going on? I was asymptomatic with respect to normal high blood pressure symptoms and my home cuff was reading much lower.
My first thought centered around arm position. Perhaps the practice of reading blood pressure when the arm was hanging down vertically instead of horizontal was the culprit.
The American Heart Association (AHA) recommends the cuff should be level with the heart while the arms rests on a flat surface. Could my vertically hanging arm make a difference? Read here for the AHA's guidelines.
Back at home I tried taking blood pressure readings with my arm resting in many different directions. What I found was it really did not make a significant amount of difference how my arm was positioned with variances of ten points or so being the maximum.
Next I suggested to my health care professional they rest my arm per AHA protocol just to be consistent. Ultimately though, arm positioning did not provide an answer to the 30 point or more differences between my home cuff and the health care professional's auscultation method.
In the auscultation method, the health care professional inflates the cuff to a pressure that stops blood flow with compression of the arm's brachial artery. As pressure is released the brachial artery blood flow resumes and produces an audible sound known as a 'Korotkoff' sound (K-sound). The pressure at which the Korotkoff sound is heard translates into the systolic blood pressure reading.
As additional cuff pressure is released the restriction in the brachial arterial decreases until finally there is no more audible tapping or k-sounds. The pressure which no additional Korotkoff sounds are heard is the diastolic blood pressure reading.
Finally I asked the nurse to use a cart-based 'doctor-on-a-stick' unit to measure my blood pressure, just to see if there was a difference. Perhaps the 'doc-on-a-stick' would exclude the heart valve noise.
The computerized cart based unit came back with a systolic reading significantly lower than the nurse's auscultatory method. The nurse shrugged and suggested the variance was due to my 'white coat syndrome' or doctor visit stress levels.
Unfortunately, the medical clinic's high systolic readings were taking their toll on me. Not only was I stressing over the worry what high systolic blood pressure could do to my existing descending aortic dissection, but my health care professionals were now suggesting changes to my medications to further manage my alleged hypertension.
Last thing I was interested in was higher doses of blood pressure medications. Metoprolol already had me feeling like a tall, red headed zombie.
Back on the internet I searched on a few more specific term combinations.
One search returned a helpful article entitled, "Antecubital Transmission of Mechanical Valve Closure Sounds; Recognition of a Potential Source of Error During Blood Pressure Measurement". The link here opens the article in a new window.
I had to read the article about five times. Pumphead masks simplicity.
What I understood the paper discussion to propose was, because mechanical valve sounds travel through extravascular tissue they may be heard even when the cuff is inflated at high pressures. Unless the health care professional is substantially familiar with what a mechanical valve sounds like through a stethoscope, a heart valve click could be mistaken for the first k-sound and a false systolic reading obtained.
One may ask, 'is this a big deal, really?'
Yes. Patient worry about hypertension that may not exist is unnecessary. Too, I have a St. Jude mechanical valve. Maybe my health care professionals were hearing my valve clicks rather than Korotkoff sounds. Perhaps my systolic was not really that high.
More importantly, prescribing a patient additional hypertension medicines unnecessarily could have significant impact and perhaps even create damaging hypotension.
The most important take away is not blood pressure measurement procedure. The most important takeaway I am learning from all this is I must be my own best health care advocate.
Trust in the health care system is so much better when I learn about, verify, confirm, obtain a second opinion and most of all trust my own instincts. When in doubt step back then verify.
After all, our number one priority in life is to stay alive. My doctor told me that.