As that evening’s nurse, Kate Murphy, watched the output on our home pulse-oximeter, she saw Tina’s pulse rate decrease suddenly from the eighties per minute to half that, forties per minute, stay there a few minutes and then return to her normal rates. Kate called me to Tina’s bed, where my most precious person, my wife of twenty-eight years, spends twenty-three hours a day. She is quadriplegic, ventilator-dependent, fed only through a gastric tube …and has been this way for the past nine years, due to multiple sclerosis.
Kate shifted the oximeter probe from Tina’s thumb to her big toe. Normal readings came for awhile, then half-normal readings, then normal again. It wasn’t due to the location of the probe.
We used a second pulse-oximeter, tried both locations and got similar results. It was not instrument error.
Through all of this, Tina’s blood oxygen remained at or near 100% of saturation, so we knew she was not in immediate danger of hypoxia.
It was eight at night, April 3rd,Tina’s birthday. I called our family doctor and discussed our situation with him. It was not an emergency, he decided, but it did warrant calling an ambulance and bringing her to the hospital, twenty miles from our home. Possible causes: morphine, constipation, electrolyte imbalance [too much calcium, not enough magnesium or potassium]. Away she went, with me in the ambulance with her, and Kate following soon after.
Kate had noticed that her stethoscope gave “lub-DUB…lub-DUB“ during the normal intervals and “lub-DUB-lub……lub-DUB-lub” during the half-rate periods.
In the Emergency Room, Tina was evaluated and triaged. She was adjudged not to be in crisis. Looking at the heart rate monitor, we saw occasional half-rate occurrences; they had a different pulse shape, as well as a greater spacing between pulses.
A nurse took blood samples. We waited for hours. Eventually that evening, Tina was given an antidote to her usual morphine painkiller, and liquid Tylenol was given for pain control. Kate stayed overnight, while I returned home at 3 a.m. We arranged for our in-home nursing staff to go to the hospital instead.
The next morning, Tina was examined by a cardiologist, who pronounced her heart to be in fine condition. An abdominal MRI that afternoon showed no problems there, either, and she was released to go home that evening. She had a clean bill of health, oddly. Reassuring…but.
What had happened? The best explanation we got came from Tina’s sister’s husband, a cardiologist. He suggested I look up “premature ventricular contraction,” and when I did, I found it matched Tina’s pulse pattern to a T. A second partial heart beat comes too soon after the first to be fully effective and to be counted by the pulse rate meter.
The good news was that this is not a rare or dangerous condition, unless it persists. We can lower the likelihood of a recurrence by lowering the levels of Tina’s painkiller and adjusting her mineral supplements. We are doing so with success.
A kind of April Fools’ Day joke is to tell someone that they are in imminent danger of something, and then after they have been scared a bit, assure them it is not really going to happen. Tina’s birthday in early April coincided with a scary heart-rate problem that turned out to be innocuous, sort of an April fool…and her all-is-fine hospital check-up became an unusual birthday present, a little too exciting.
Doug, you need to get my brother David Gerdt's Caretaker. You would have had beat to beat monitoring.blue tooth. Pvc's can be from low magnesium and potassium. Milk of magnesia is a good supplement. Happy Birthday belated Tina. Good job Doug and Katie. You should write a book about how you did all that in one day...great doctors, well defined plan. No one at hospital copped an attitude. As good as it gets! best wishes, mary
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