Apple Releases watchOS 5.1.2 With ECG, New Infograph Complications and Walkie-Talkie Control Center Toggle - MacRumors
Skip to Content

Apple Releases watchOS 5.1.2 With ECG, New Infograph Complications and Walkie-Talkie Control Center Toggle

Apple today released watchOS 5.1.2, the third update to the watchOS 5 operating system that runs on modern Apple Watch models. watchOS 5.1.2 comes one month after the release of watchOS 5.1.1, an update that introduced new emoji and color watch faces and addressed a bricking bug that had been introduced with watchOS 5.1.

watchOS 5.1.2 can be downloaded for free through the dedicated Apple Watch app on the iPhone by going to General --> Software Update. To install the new software, the Apple Watch needs to have at least 50 percent battery, it needs to be placed on a charger, and it needs to be in range of the iPhone.

applewatchseries4ecgfeature
watchOS 5.1.2 introduces the long-awaited ECG feature for Apple Watch Series 4 models in the United States. The ECG functionality works through electrodes built into the back of the Apple Watch Series 4 and the Digital Crown, allowing users to take a single-lead electrocardiogram with the wrist-worn device. An ECG measures the electrical activity of the heart and is often used to diagnose heart conditions.

Alongside ECG functionality, watchOS 5.1.2 introduces a new feature that will let you know if the Apple Watch is detecting an abnormal heart rhythm that's indicative of atrial fibrillation, which can be a sign of a serious health problem. The ECG feature is limited to the Series 4, but the irregular heart rhythm notifications will be available on all Apple Watch models able to run watchOS 5 - that's Series 1 or newer.

The watchOS 5.1.2 update also brings new complications for the Infograph watch faces on the Apple Watch Series 4. Complications that have been added include Mail, Messages, Home, Maps, Apple News, Find My Friends, Phone, and Remote, all of which can now be assigned to the available complication slots on the Infograph watch face.

watchos512changes
With most of these complications, the icon is designed to provide quick access to opening up an app rather than relaying information like unread messages or emails.

watchOS 5.1.2 also includes a new toggle in Control Center for turning the Walkie-Talkie feature on and off, which makes it a lot easier to disable Walkie-Talkie when it's not in use and turn it back on when it's needed.

Apple's release notes:

This update includes new features, improvements and bug fixes:

- New ECG app on Apple Watch Series 4 (US and US territories only)
* Allows you to take an electrocardiogram similar to a single-lead electrocardiogram
* Can indicate whether your heart rhythm shows signs of atrial fibrillation—a serious form of irregular heart rhythm—or sinus rhythm, which means your heart is beating in a normal pattern
* Saves ECG waveform, classification and any noted symptoms in a PDF on the Health app on iPhone to share with your doctor

- Adds the ability to receive an alert if an irregular heart rhythm that appears to be atrial fibrillation is detected (US and US territories only)

- Enables direct access to supported movie tickets, coupons, and rewards cards in Wallet when tapped to a contactless reader

- Receive notifications and animated celebrations when you achieve daily maximum points in a day during an Activity competition

- New Infograph complications for Mail, Maps, Messages, Find My Friends, Home, News, Phone, Remote

- Manage your availability for Walkie-Talkie from Control Center

More details on the features introduced with the watchOS 5 update that came out in September can be found in our watchOS 5 roundup.

Related Roundup: Apple Watch 11
Tag: ECG
Buyer's Guide: Apple Watch (Neutral)

Popular Stories

imac video apple feature

Apple Released Yet Another New Product Today

Friday March 20, 2026 2:39 pm PDT by
Apple has unveiled a whopping nine new products so far this March, including an iPhone 17e, iPad Air models with the M4 chip, MacBook Air models with the M5 chip, MacBook Pro models with M5 Pro and M5 Max chips, the all-new MacBook Neo, an updated Studio Display, a higher-end Studio Display XDR, AirPods Max 2, and now the Nike Powerbeats Pro 2. iPhone 17e features the same overall design as...
iPhone 18 Pro Deep Red Feature

iPhone 18 Pro Launching Later This Year With These 12 New Features

Wednesday March 18, 2026 7:39 am PDT by
While the iPhone 18 Pro and iPhone 18 Pro Max are not expected to launch for another six months or so, there are already plenty of rumors about the devices. It was initially reported that the iPhone 18 Pro models would have fully under-screen Face ID, with only a front camera visible in the top-left corner of the screen. However, the latest rumors indicate that only one Face ID component...
ios 26 4 pastel

iOS 26.4: Top 10 New Features Coming to Your iPhone

Friday March 20, 2026 2:44 pm PDT by
iOS 26.4 isn't the major update with new Siri features that we hoped for, but there are some useful quality of life improvements, and a little bit of fun with an AI playlist generator and new emoji characters. Playlist Playground - Apple Music has a Playlist Playground option that lets you generate playlists from text-based descriptions. You can include moods, feelings, activities, or...

Top Rated Comments

lanegandy Avatar
95 months ago
US and US territories only
Disappointed with you Apple.
It's because it's a medical device that requires approval from the government. Blame your government, not Apple.
Score: 11 Votes (Like | Disagree)
seatton Avatar
95 months ago
Returning my Series 4 because the update has not shown up yet... it is already 10:04 AM here... / s
Score: 10 Votes (Like | Disagree)
95 months ago
US and US territories only
Disappointed with you Apple.
Why are you disappointed? Doesn’t this require approval for each country? It’s out of Apple’s hands
Score: 7 Votes (Like | Disagree)
fruitpunch.ben Avatar
95 months ago
First one to post a screenshot with AFib wins!
Score: 5 Votes (Like | Disagree)
GuilleA Avatar
95 months ago
I had a proper ECG last week at the doctor's office and did one just now with the app. I'm not by any means trained to read it, but the graphs look extremely similar.

Attachment Image

Attachment Image
Score: 5 Votes (Like | Disagree)
ghostface147 Avatar
95 months ago
Now for people to take ECG readings every 10 minutes to see what's going on and think they are dying.
Score: 5 Votes (Like | Disagree)