Our friend Hal was diagnosed with atrial fibrillation, or AFib, two years ago. It's an irregular heartbeat, and his cardiologist keeps a close eye on it. For Christmas, his wife gave him an Apple Watch, and he turned on a feature called AFib History. Every week, it shows a little chart estimating how much of the time his heart was in AFib.
Hal loves that chart. Maybe a little too much. Last month he told Bob, "My AFib number was down to 2 percent this week. I figure I can skip that blood thinner for a few days." Bob nearly dropped his coffee.
Hal didn't skip it, thank heavens. His wife made him call his cardiologist first. But his comment worried me, because I think a lot of us trust the numbers on our wrists more than we should.
What is Apple Watch AFib History?
AFib History is a feature on supported Apple Watch models for people who have already been diagnosed with AFib by a doctor. Apple explains that it's meant for people 22 and older with an AFib diagnosis, and it gives a weekly estimate of how often your heart showed signs of AFib. You need to wear the watch enough for it to have data.
It's a report of what happened, like a weekly summary. It is not a live alarm.
What AFib History does, and what it doesn't do
In plain words, AFib History gives a weekly estimate of time spent in AFib for people who've been diagnosed, shows patterns over time, and creates a report you can share with your doctor. It doesn't alert you in the moment during an AFib episode, it can't detect a heart attack or a stroke, and it should never be what tells you to change your medicine.
Apple has a separate feature called irregular rhythm notifications that can alert people who haven't been diagnosed. That's a different tool, so ask your doctor which one, if either, makes sense for you.
How should I use my AFib report with my doctor?
Treat it as helpful information, not instructions. Ask your cardiologist whether they want to see it, and how. Some offices can receive an exported report, and some would rather you bring it up at your visit. Check the dates on the report before you share it.
It also helps to jot down how you felt on days the numbers were higher, like tired, short of breath, or fluttery. And keep your medication list up to date, especially blood thinners. Never stop, skip, or change a heart medicine because of a number on your watch. Call your doctor instead.
What heart symptoms mean I should call 911?
Put simply, don't wait for your watch. Call 911 right away for chest pain, pressure, or squeezing, trouble breathing, especially if it's sudden, fainting or nearly passing out, or signs of a stroke, like one side of the face drooping, one arm feeling weak, or slurred speech. People with AFib have a higher risk of stroke, so those signs are especially important to know.
A calm-looking chart doesn't mean everything is fine. Your symptoms always come first.
What Hal does now
Hal's cardiologist was glad to see his AFib report, and they look at it together at his checkups. But Hal has a new rule, written on a card in his wallet: "The watch reports. The doctor decides." He takes his blood thinner every single day, no matter what the chart says. And his wife set up his Medical ID with his AFib diagnosis and medicines, just in case. If he wears the watch for fall safety too, we explained what to check in the fall detection settings.
Take good care of yourself, and take even better care of each other.
Do you use a health feature on your watch? Tell me in the comments how you share it with your doctor.
