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.
Apple accounted for roughly 90% of all Edge AI-capable smartwatch shipments in the first quarter of 2026, according to new data from Counterpoint Research.
That dominance came as Edge AI penetration across the broader smartwatch market grew 70% year-over-year, reaching 25% in the first quarter of 2026, according to Counterpoint's Global Smartwatch Shipments Tracker.
"Edge AI" refers to...
The European Commission yesterday adopted new exemptions to its Batteries Regulation that free the Apple Watch and AirPods from having to offer user-removable and replaceable batteries.
The EU's Batteries Regulation generally requires consumer products sold in the region to let users swap out their own batteries, a push meant to keep devices in use longer and make it easier to recover...
With the Apple Watch Series 12 now just two months away, we have created a recap of rumored new features, with some more likely than others.
Below, we have outlined everything rumored so far for the Apple Watch Series 12.
More Likely
New Chip After One-Year Hiatus
While the Apple Watch Series 11, Apple Watch Ultra 3, and Apple Watch SE 3 all contain the same S10 chip as the previous...
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*
Apple's first foldable iPhone, with a book-style design featuring a ~5.5-inch outer display and a ~7.8-inch inner display with a minimal crease down the middle.
