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.
iOS 26.4 was released today, and it includes a couple of new features for CarPlay: an Ambient Music widget and support for voice-based chatbot apps.
To update your iPhone 11 or newer to iOS 26.4, open the Settings app and tap on General → Software Update. CarPlay will automatically offer the new features so long as the iPhone connected to your vehicle is running iOS 26.4 or later....
Tuesday March 24, 2026 12:31 pm PDT by Juli Clover
Apple today released new firmware for the AirPods Pro 2, AirPods Pro 3, and the AirPods 4. The firmware has a version number of 8B39, up from 8B34 on the AirPods Pro 3, 8B28 on the AirPods Pro 2, and 8B21 on the AirPods 4.
There is no word on what's included in the firmware, but Apple has a support document with limited notes. Most updates are limited to bug fixes and performance...
Wednesday March 25, 2026 3:33 pm PDT by Joe Rossignol
Apple this week released tvOS 26.4, and the software update includes a handful of new features and changes for the Apple TV.
tvOS 26.4 is compatible with all Apple TV 4K and Apple TV HD models released since 2015. To update your Apple TV, open the Settings app on the device, navigate to System → Software Updates, and select Update Software.
Below, we have recapped what is new in tvOS...
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*
