Today, with an update to watchOS, Apple is making its
electrocardiogram reading feature available to Apple Watch
Series 4 owners. It’s also releasing an irregular rate
notification feature that will be available on Apple Watches
going back to Series 1. Both are a part of watchOS 5.1.2.
Apple Watch Series 4 was announced this past September, the
most significant new hardware feature besides the larger screen
was probably the ability to take an ECG directly on the watch.
And while the electrodes on the digital crown and the backside
of the watch were there, the software to support them hadn’t
been released. Now it’s here.
To take an ECG, you open up the ECG app on the watch and
lightly rest your index finger on the crown for 30 seconds. The
watch then acts like a single-lead ECG and will read your heart
rhythm and record it into the Health app on your phone. From
there, you can create a PDF report to send to your doctor.
The irregular heart rate monitoring is passive. Apple says that
it checks your rhythm every two hours or so (depending on
whether you’re stationary or not), and if there are five
consecutive readings that seem abnormal, it will alert you and
suggest you reach out to a doctor. If you have been previously
diagnosed with atrial fibrillation, Apple’s setup process tells
you not to use the feature.
Apple tells me these features are most definitely not
diagnostic tools. In fact, before you can activate either of
them you will need to page through several screens of
information that try to put their use into context and warn you
to contact your doctor if needed. Nor are they the sort of
features Apple expects users to really use on a regular basis.
The ECG feature in particular should only really be used if you
feel something abnormal going on, and then you should only
share the resulting report with your doctor, not act on it
I wanted to get those caveats stated clearly. Firstly because
they’re important — don’t assume the Apple Watch can replace
talking to a doctor and don’t try to self-diagnose with it.
Secondly because these caveats can help put you in the right
frame of mind for understanding how the Apple Watch is changing
and how entering this new health space is neither simple nor
Apple has received “de novo” clearance from the FDA for these
features, which are a first for a consumer product you can just
go and buy directly. But one example of how this new use of
technology is complicated is that FDA “clearance” is not the
same thing as FDA “approval,” as
Angela Chen has explained:
The Apple Watch is in Class II. For Class II and Class I, the
FDA doesn’t give “approval,” it just gives clearance. Class I
and Class II products are lower-risk products — as [Jon
Speer, co-founder of Greenlight Guru] puts it, a classic
Class I example is something like a tongue depressor — and
it’s much easier to get clearance than approval.
Most people think of the Apple Watch as a fitness tracking
device, but increasingly it is becoming a health monitoring
device — especially the Series 4, which along with the new ECG
can detect if its wearer suddenly falls to the ground. And all
Apple Watches Series 1 and up can now keep an eye out for
irregular and abnormally low or high heart rates.
But in this new kind of gadget world, understanding what a
health monitoring device can and can’t do is essential. It
can detect those things and that is genuinely good,
but it doesn’t necessarily mean that it will, nor that
you should depend on it to do so. It’s more of a backstop — or
another source of data you can provide to your doctor.
With the ECG feature, that extra data could prove valuable.
Apple says that having a potential ECG monitor on your wrist at
all times means that you can get a reading at the moment you’re
feeling your heart race, for example, instead of just
describing it to your doctor later. But the risk is that people
might not use that data properly, e.g. they might use it for
Apple’s onboarding experience goes some way toward keeping you
from falling into that trap. For both features, you’ll need to
tap through several screens of information about atrial
fibrillation and other heart issues. The design of that screen
flow encourages actually reading about what you’re turning on,
too, instead of just scrolling by and hitting accept like you
do with the iTunes terms of service. There are specific
animations, graphics, and pauses that feel like they’re
designed to encourage users to pay attention.
I tried the ECG feature a couple of times but, as I am not a
doctor, I can’t tell you whether or how accurate it is. One
thing I could not test (thankfully) was the irregular heartbeat
notification. There again, Apple is trying to be super clear
that you should reach out to a doctor rather than act on the
notification itself directly.
Both features are limited to the US for now, and should be
available today as part of the WatchOS 5.1.2 update.