Apple Says watchOS 5.1.2 Coming Today With ECG App Enabled on Apple Watch Series 4

Apple has announced that watchOS 5.1.2 will be publicly released today and will enable the long-awaited ECG app on Apple Watch Series 4 models in the United States. The update will also enable irregular heart rhythm notifications on Apple Watch Series 1, Series 2, Series 3, and Series 4 models.

iphone apple watch ecg
watchOS 5.1.2 should be available through the Apple Watch app on a paired iPhone around 10:00 a.m. Pacific Time as usual.

Apple's COO and Apple Watch team head Jeff Williams:

Apple Watch has helped so many people around the world and we are humbled that it has become such an important part of our customers' lives. With the release of these heart features, Apple Watch takes the next step in empowering people with more information about their health.

Last week, MacRumors was first to report that watchOS 5.1.2 will enable the ECG app on Apple Watch Series 4 models, based on an internal Apple Store training document. ECG data will be available in the Health app and exportable via PDF on an iPhone 5s or newer, after updating to iOS 12.1.1 released yesterday.

watchOS 5.1.2 will feature an Apple-designed ECG app that can indicate whether your heart rhythm shows signs of atrial fibrillation, a serious form of irregular heart rhythm, or a normal sinus rhythm. This is possible thanks to new electrodes built into the back crystal and Digital Crown on Series 4 models.

Apple Watch Series 4 is capable of generating an ECG similar to a single-lead electrocardiogram, according to the FDA. Both the ECG app and irregular heart rhythm notifications are regulated features that have received De Novo classification from the FDA, making them available over the counter.

The ECG app will check heart rhythm every few hours or so, and if there are five consecutive readings that appear to be abnormal, the Apple Watch will alert the user to see a doctor. As for notifications, users will be alerted if an irregular heart rhythm is detected on five checks over a minimum of 65 minutes.

Importantly, in an internal document obtained by MacRumors, Apple cautioned that the ECG app is "not intended to be a diagnostic device or to replace traditional methods of diagnosis," and "should not be used to monitor or track disease state or change medication without first talking to a doctor."

To take an ECG reading from the Apple Watch, users will need to place a finger on the Digital Crown while wearing the watch. The reading is completed in 30 seconds, allowing users to determine whether their hearts are beating in a regular pattern or if there are signs of atrial fibrillation.

Apple says the ECG app's accuracy was validated in a clinical trial of around 600 participants in the United States:

Rhythm classification from a gold standard 12-lead ECG by a cardiologist was compared to the rhythm classification of a simultaneously collected ECG from the ECG app. The study found the ECG app on Apple Watch demonstrated 98.3 percent sensitivity in classifying AFib and 99.6 percent specificity in classifying sinus rhythm in classifiable recordings. In the study, 87.8 percent of recordings could be classified by the ECG app.

Apple is making good on its promise of making the ECG app available by year's end. watchOS 5.1.2 has been in beta testing since November 7, but the ECG app was nowhere to be found during the pre-release period.

Apple says the setup process for these heart health features will include details about who can use the features, what the features can and cannot do, what results users may get and how to interpret them, and instructions for what to do if users are feeling symptoms that require immediate medical attention.

Related Roundup: Apple Watch 10
Tag: ECG
Buyer's Guide: Apple Watch (Caution)

Popular Stories

maxresdefault

Five Features Coming to AirPods Pro 3

Friday June 27, 2025 10:52 am PDT by
Apple hasn't updated the AirPods Pro since 2022, and the earbuds are due for a refresh. We're counting on a new model this year, and we've seen several hints of new AirPods tucked away in Apple's code. Rumors suggest that Apple has some exciting new features planned that will make it worthwhile to upgrade to the latest model. Subscribe to the MacRumors YouTube channel for more videos. Heal...
iPhone Car Key WWDC 2025

Apple Announces 13 Automakers Planning to Offer iPhone Car Keys

Friday June 27, 2025 11:42 am PDT by
In 2020, Apple added a digital car key feature to its Wallet app, allowing users to lock, unlock, and start a compatible vehicle with an iPhone or Apple Watch. The feature is currently offered by select automakers, including Audi, BMW, Hyundai, Kia, Genesis, Mercedes-Benz, Volvo, and a handful of others, and it is set to expand further. During its WWDC 2025 keynote, Apple said that 13...
anker power bank recall

PSA: Anker Recalls Multiple Power Banks Due to Fire Risk

Friday June 27, 2025 4:16 pm PDT by
Popular accessory maker Anker this month launched two separate recalls for its power banks, some of which may be a fire risk. The first recall affects Anker PowerCore 10000 Power Banks sold between June 1, 2016 and December 31, 2022 in the United States. Anker says that these power banks have a "potential issue" with the battery inside, which can lead to overheating, melting of plastic...
Chase Sapphire Reserve Apple Perk Feature

Chase Sapphire Reserve Card Introduces New Perk for Apple Customers

Wednesday June 25, 2025 2:08 pm PDT by
Chase this week announced a series of new perks for its premium Sapphire Reserve credit card, and one of them is for a pair of Apple services. Specifically, the credit card now offers complimentary annual subscriptions to Apple TV+ and Apple Music, a value of up to $250 per year. If you are already paying for Apple TV+ and/or Apple Music directly through Apple, those subscriptions will...
iPhone 17 Pro Blue Feature Tighter Crop

iPhone 17 Pro Launching in a Few Months With These 12 New Features

Thursday June 26, 2025 2:00 am PDT by
Apple's next-generation iPhone 17 Pro and iPhone 17 Pro Max are around three months away, and there are plenty of rumors about the devices. Apple is expected to launch the iPhone 17, iPhone 17 Air, iPhone 17 Pro, and iPhone 17 Pro Max in September this year. Below, we recap key changes rumored for the iPhone 17 Pro models:Aluminum frame: iPhone 17 Pro models are rumored to have an...
A18 Pro Chip

New MacBook With A18 Pro Chip Spotted in Apple Code

Monday June 30, 2025 8:05 am PDT by
Apple is developing a MacBook with the A18 Pro chip, according to findings in backend code uncovered by MacRumors. Earlier today, Apple analyst Ming-Chi Kuo reported that Apple is planning to launch a low-cost MacBook powered by an iPhone chip. The machine is expected to feature a 13-inch display, the A18 Pro chip, and color options that include silver, blue, pink, and yellow. MacRumors...
macbook air spacegray purple

Apple Planning to Launch Low-Cost MacBook Powered By iPhone Chip

Monday June 30, 2025 3:20 am PDT by
Apple is planning to launch a low-cost MacBook powered by an iPhone chip, according to Apple analyst Ming-Chi Kuo. In an article published on X, Kuo explained that the device will feature a 13-inch display and the A18 Pro chip, making it the first Mac powered by an iPhone chip. The A18 Pro chip debuted in the iPhone 16 Pro last year. To date, all Apple silicon Macs have contained M-series...
CarPlay Ultra Climate Controls

Here's Which Vehicle Brands Will and Won't Offer Apple's CarPlay Ultra

Friday June 27, 2025 9:52 am PDT by
Apple last month announced the launch of CarPlay Ultra, the long-awaited next-generation version of its CarPlay software system for vehicles. There was news this week about which automakers will and won't offer CarPlay Ultra, and we have provided an updated list below. CarPlay Ultra is currently limited to newer Aston Martin vehicles in the U.S. and Canada. Fortunately, if you cannot...
apple watch ultra 2 new black

Apple Watch Ultra 3 Finally Coming After Two-Year Hiatus

Tuesday June 24, 2025 3:40 am PDT by
Apple will finally deliver the Apple Watch Ultra 3 sometime this year, according to analyst Jeff Pu of GF Securities Hong Kong (via @jukanlosreve). The analyst expects both the Apple Watch Series 11 and Apple Watch Ultra 3 to arrive this year (likely alongside the new iPhone 17 lineup, if previous launches are anything to go by), according to his latest product roadmap shared with...

Top Rated Comments

SteveOfTheStow Avatar
86 months ago
And 99% of users will try it once, find out their heart is normal and never touch it again, despite vehemently demanding it every day for the past 2 months.
Score: 15 Votes (Like | Disagree)
Piggie Avatar
86 months ago
Fingers crossed. :rolleyes:
Not sure it will work correctly if you keep your fingers crossed ;)
Score: 9 Votes (Like | Disagree)
Return Zero Avatar
86 months ago
And 99% of users will try it once, find out their heart is normal and never touch it again.
True... Statistically, the percentage of people who don't have any heart rhythm issues is more like 95%. However, for that remaining 5%, including my wife who has SVT, it is literally a potential life saver!
Score: 8 Votes (Like | Disagree)
Steve121178 Avatar
86 months ago
so, do i have to permanently (until it comes to UK/EU) move my AppleID to US to make ECG work properly?
It should be approved in the EU/UK by around 2053, just in time for the iPhone 28s & Apple Watch 19.
Score: 7 Votes (Like | Disagree)
tromboneaholic Avatar
86 months ago
And 99% of users will try it once, find out their heart is normal and never touch it again, despite vehemently demanding it every day for the past 2 months.
Irregular heart rhythm notifications will also be enabled in watchOS 5.1.2 on Series 1 through Series 4.

Hopefully less than 1% of users need this feature as well, but it will be a passive feature that doesn't require anything besides wearing the watch.
Score: 6 Votes (Like | Disagree)
thadoggfather Avatar
86 months ago
I’m infinitely curious how well or not well this works, since Apple software quality control (in general not just the watch) has taken a serious nosedive in the past several years

5.1 bricked watches! 5.1.1 fixed it supposedly, and now 5.1.2 will be in control of your ECG monitoring. That’s quite the progression
Score: 6 Votes (Like | Disagree)