WHAT THIS POST IS ABOUT. It’s a bit of a follow-up to I (Heart) Notion, only here I note the accuracy of the Series 4 Apple Watch.


I picked up a heart monitor this morning at my cardiologist’s office. As the technician prepared me to wear the device for the next 24-36 hours, she said: “Do you know you’re in Afib? Do you feel it?”

I have a long history with atrial fibrillation, successfully living with the heart condition for more than 20 years, but I just said simply, “Yes.” I didn’t think she wanted a book report on my Afib.

I said, “I use an Apple Watch to keep watch on my heart. You say I’m in Afib. Let’s compare your numbers with mine to see how accurate this watch is.”

Critics of the Apple Watch, including doctors and others in the medical profession, often say the Apple Watch and other consumer healthcare tech products are not as accurate as the equipment in doctor offices and hospitals, therefore they are not to be trusted.

Bah! Every time I am in the doctor’s office and measurements are taken I compare the results. And every time the watch is either dead-on or within one or two beats of the “professional” equipment. Of course the one-lead Apple Watch doesn’t generate as many data points as a multi-lead EKG machine, but I argue the watch does give me — and health consumers — an idea of what’s going on. It’s better than nothing.

Pretty much every day there seems to be a new story about the Apple Watch “saving” somebody’s life. Or, in this case, alerting someone that Afib has returned.

Some doctors, nurses, and critics complain that the Apple Watch and other health “wearables” create false positives and misinformation, leading people to think they have Afib or a heart condition when they do not. People race into their doctor’s office demanding answers and yada, yada, yada . . .

Whatever. That’s a topic for another day.

Whether skeptical doctors or nurses like it or not, many of these devices — especially the Series 4 Apple Watch — are pretty damn accurate and, when used smartly by the consumer/patient, they can provide reams of valuable information and insight (see my post on this topic). It’s what you do with the data, how and if you use it, that’s important.

Back in the cold office, I tell the technician I am there because of the data I collected over the past three-plus weeks. Something seems off. Something isn’t right. And it’s more than just the Series 4 watch indicating I have “Atrial Fibrillation” when using ECG function.

Afib is a mysterious affliction. It’s a common heart issue, yet it’s not really curable, it comes and goes, and it’s frustrating as hell for the patient (and, most likely, the cardiologist and electrophysiologist). For people who’ve never “had” Afib, it’s a no-brainer: Get in touch with your doctor and find out what’s going on.

While the Series 4 watch is not actually meant for people with Afib (amazingly — and yes, I’ve seen Apple comment on this), those of us who do have Afib can use it to help manage the condition, something I’ll post on when I get the chance.

Should I have called the doctor immediately? I’ve been in this position hundreds of times before. I know when to call the doctor and when to go to the ER. In this case, it’s not one or two incidences of Afib that appear on the watch because these happen several times a day for me.

Data collected by HeartWatch app.

It’s thousands of data points collected not just over 24 hours but over a week, two weeks, a month. It’s me collecting the data, trying to understand it, looking for trends, and deciding it’s time to call the doctor to tell him or the nurse something seems amiss.

(Aside: Hey, wait, am I conducting Evidence Based Practice here? I think so.)

The technician said, “I’ve got 120, 121, 122. You’re in Afib.”

“I know. I’m at 121, 122,” I said.

I left the office, saying: “This is good. At least I know the watch is pretty accurate.”

Now, let’s see how my data over the next 24-36 hours stacks up to what’s collected by the heart monitor and what the cardiologist thinks.I

Follow-up: The electrophysiologist said I averaged 112 beats per minute for the day (which was actually about 26-27 hours). The Apple Watch and HeartWatch indicated 114 (23-24 hours). Not bad. Not bad at all.


Sorry about the belly flab picture but, hey, it’s real. It’s me, not a belly stunt-double from a stock photography service.

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