Apple has designed a new algorithm that Apple Watch uses to measure electrocardiogram (ECG) waves, according to developer documentation for the iOS 14.3 and watchOS 7.2 betas.
In the official documentation, a new "version 2 algorithm" declaration has been added. No other information is included.
The ECG feature includes irregular heart rhythm detection, which intermittently measures the user's heart rate in the background and sends a notification if it detects an anomaly it categorizes as atrial fibrillation, which can be a serious heart arrhythmia condition.
Based on beta code uncovered by MacRumors, it's likely that the new algorithm will allow the ECG app to check for atrial fibrillation (AFib) at higher heart rates - during exercise, for example.
iOS 14.3 will introduce support for Apple Fitness+, Apple's upcoming fitness service that will work with the Apple Watch, plus it brings a new Cardio Fitness feature that lets you know if your VO2Max levels are low. VO2Max is a useful measurement of overall fitness and heart health.
iOS 14.3 is set to be released on Monday, December 14, which is also the day that Apple Fitness+ is coming out.
Monday January 26, 2026 1:55 pm PST by Joe Rossignol
Apple today introduced its first two physical products of 2026: a second-generation AirTag and the Black Unity Connection Braided Solo Loop for the Apple Watch.
Read our coverage of each announcement to learn more:Apple Unveils New AirTag With Longer Range, Louder Speaker, and More
Apple Introduces New Black Unity Apple Watch BandBoth the new AirTag and the Black Unity Connection Braided...
Monday January 26, 2026 3:56 pm PST by Juli Clover
Alongside iOS 26.2.1, Apple today released an updated version of iOS 12 for devices that are still running that operating system update, eight years after the software was first released.
iOS 12.5.8 is available for the iPhone 5s and the iPhone 6, meaning Apple is continuing to support these devices for 13 and 12 years after launch, respectively. The iPhone 5s came out in September 2013,...
Monday January 26, 2026 6:07 am PST by Joe Rossignol
Apple today introduced the second-generation AirTag, with key features including longer range for tracking items and a louder speaker.
For those who are not familiar, the AirTag is a small accessory that you can attach to your backpack, keys, or other items. Then, you can track the location of those items in the Find My app on the iPhone, iPad, Mac, Apple Watch, and iCloud.com.
The new...
Sunday January 25, 2026 6:02 pm PST by Joe Rossignol
2026 promises to be yet another busy year for Apple, with the company rumored to be planning more than 20 product announcements over the coming months.
Beyond the usual updates to iPhones, iPads, Macs, and Apple Watches, Apple is expected to release its all-new smart home hub, which was reportedly delayed until the more personalized version of Siri is ready. Other unique products rumored for ...
Sunday January 25, 2026 11:46 am PST by Joe Rossignol
Apple plans to release new MacBook Pro, MacBook Air, Mac Studio, and Studio Display models in the first half of this year, according to Bloomberg's Mark Gurman.
In his Power On newsletter today, Gurman added that redesigned MacBook Pro models with an OLED touch screen "should be hitting toward the end of 2026," meaning that the MacBook Pro line would be upgraded twice this year.
First up...
Wait what? The ECG only works when your finger is on the Digital Crown. It can’t work in the background.
The background irregular heart rhythm detection does not use the ECG but it is grouped with the ECG features (which is technically inaccurate but they are related features, just different technologies). It's been around as long as the ECG: "Using the optical heart sensor in Apple Watch Series 1 or later, the irregular rhythm notification feature will occasionally check the user’s heart rhythm in the background for signs of an irregular heart rhythm that appears to be AFib and alerts the user with a notification if an irregular rhythm is detected on five rhythm checks over a minimum of 65 minutes." (https://www.apple.com/newsroom/2018/12/ecg-app-and-irregular-heart-rhythm-notification-available-today-on-apple-watch/)
Still waiting for ECG in Japan! Any news about it?
Since ECG received final medical approval in Japan this September, I guess maybe iOS 14.3 will cover ECG functionality also Japan as well? *finger-crossed*
