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- If you own one of the newer Apple Watches,
the Series 4, it has this dormant feature
that was flipped on last year.
This watch can now perform
an electrocardiogram test, or EKG.
It measures the electrical signals
that your heart uses to regulate your heartbeat.
The point is to detect signs of atrial fibrillation,
which is a form of irregular heartbeat
that could cause a stroke or heart failure.
This is actually a big step for Apple.
You might think of this watch as a notification machine
for fitness buffs who want to obsessively track
every single step that they take,
but with EKG, it's trying to become something different.
Not just a fitness tracker, but now a health monitor,
but that change, it opens up a host of new questions.
- Do doctors think it's a good idea?
Are people gonna use this the right way?
Are we just giving people all this information
that they don't even understand?
- Oh, we asked our science reporter Angela
to tackle those big scary questions for us.
- Hey Deeder.
- And later, we're going to fire up
a more professional EKG at a medical lab,
but before all that, here's what this new EKG feature
actually looks like.
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The EKG process itself is pretty simple.
There are two sensors on the watch,
one on the back and one on the crown.
When you put your finger on the crown,
you're completing a circuit from your finger
to your heart and back to your wrist.
That way, the watch can measure
your heart's electrical pulses.
After 30 seconds, it'll tell you if the upper
or lower chambers of your heart are out of sync
and if they are, it's time to go see a doctor.
In my case, I'm seeing a sinus rhythm
and that should mean no AFib.
but I'm gonna go see a doctor anyway.
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We're here at the University of California San Francisco
to get an expert opinion.
See, there's already been a little bit of blow back
about this new EKG feature.
Some critics have argued that it could
lead to false positives or become a self diagnosis machine,
so we're here to do what we expect
a lot of Apple Watch owners are gonna do
which is go ask a doctor about their results.
Dr. Greg Marcus is a specialist
in heart arrhythmias at USFS.
First, he and medical assistant Vanessa Mallet
hooked me up to a lab grade EKG.
It provides 12 different readings of heart activity
instead of just the single snapshot
that you get on an Apple Watch.
- And it's just already going.
You have what's called a sinus arrhythmia,
which is a sign of good health.
- [Man] Dr. Marcus walked us through
some of the differences between the Apple Watch EKG
and this one.
Basically, this thing will give you lots more data
to help pinpoint issues that you might suspect
based on the watch's readout.
It's meant to be a two step process.
The watch flags a possible problem
and the doctor investigates further.
- So if there's an early beat for example,
the 12 lead EKG will give us more information
as to exactly where that's coming from.
- [Man] How that two step process will work in practice?
It's not clear yet.
The feature is too new.
Right now Dr. Marcus isn't really sure
what to make of it.
- We still don't know yet how frequently
that Apple Watch by itself will be sufficient
versus how often physicians will not be able,
not feel confident in that reading
and feel that some additional monitoring
needs to be done.
As a researcher, it's fascinating
and a great opportunity.
As a clinician, it's worrisome.
- The worrisome thing, the precision of the Apple Watch
is only part of the story.
In theory, the benefit of the Apple Watch
is that it'll catch these lurking heart problems
that you would otherwise never know about.
But in fact, cardiologists don't recommend using it
to screen for heart problem unless you're already at risk.
- My name's Seth Landefeld.
I'm professor of medicine and chair of
the Department of Medicine at University of Alabama
at Birmingham.
- Dr. Landefeld is a member of the US Preventive
Services task force.
They evaluate various screening tests
to see if the benefits outweigh the risks.
Recently, they looked at whether EKG screening
would help in people who are healthy
and otherwise at low risk.
They looked at it for cardiovascular disease,
bad stuff like heart attack or stroke.
- There's no evidence there that the benefits
outweigh the harms and so therefore
we recommended against using ECG screening
for people at low risk for cardiovascular disease.
- And for AFib, the condition Apple Watch screens for,
similar situation.
There's just not much evidence that EKGs are worth it
if you don't already have these other symptoms
but why not just do it anyway to be safe?
Because there's a risk of a false positive.
EKG itself is safe, but in an absolute worst case scenario,
there could be a false positive that leads to
a treatment that's unnecessary and unsafe.
- Well if it led to further tests that somebody said, jee,
it looks like you should undergo bypass surgery
and somebody underwent bypass surgery,
we know that the average mortality from bypass surgery
is one or two percent.
- There's also the issue of the users.
AFib studies focus on people 65 and older
because they're the people who are most likely
to have heart problems.
They're not the people most likely to have Apple Watches,
which makes Dr. Marcus worried that now
all the wrong people have their own EKGs.
- The individuals that tend to purchase these Apple Watches
may be those who are already health conscious,
tend to be fit, tend to probably be quite healthy,
whereas the people that really probably
have the most to benefit from atrial fibrillation screening
will tend to be the older individuals
who may be less tech savvy,
those who aren't as concerned about their health.
- All this means that EKG might be harming
all these low risk people with all this data
that might lead them to self diagnose
and get freaked out for no good reason.
For them, all this might start with
an irregular heartbeat alert.
- They check their EKG, they don't actually have
atrial fibrillation, they have an irregular rhythm
for some other reason that's totally benign.
- In reality, they're totally okay,
but now they've gotten the scary notification
that something might be wrong and they feel nervous.
- They make an appointment with me,
spend time with me and our nurses
who otherwise could be helping people
that clearly need help.
- [Angela] Again, the Apple Watch is new,
but overtime, false flags put at strain
to our entire healthcare system.
It's a classic case of data overload.
- So with all of that in mind,
what should a healthy person use this feature for?
According to Dr. Marcus, maybe nothing.
- If someone is younger than age 65,
they don't have high blood pressure, diabetes,
they've never had a stroke, they don't have heart failure,
they don't have other problems with their arteries.
In general, I would say
ignore it in the absence of symptoms.
- In the end, there's one thing
that all doctors can agree on.
If you're concerned about your heart health,
be good to your heart.
Don't smoke, get plenty of exercise,
and keep an eye on your blood pressure.
You don't need an EKG feature on your Apple Watch
to do any of that and your doctor will love you for it.
- See how your rhythm speeds up a little bit
and then it slows down?
People who have more of this sort of variability
tend to live longer.
- Oh really?
Okay, well great.