Just in, iOS 14.3 and watchOS 7.2 updates will include Apple’s improved (version 2) ECG feature. We expect these iPhone and Apple Watch upgrades to drop as early as next week (starting Dec. 14.)
Apple’s improved ECG feature recently received FDA approval. 
The enhanced ECG comes years after the company successfully received approval for its original ECG function via de-novo.
This second-generation ECG feature expands the classification range all the way to 150 beats per minute.
The new ECG feature is available on the Apple Watch on an on-demand basis. 
If a user has Atrial fibrillation and a heart rate between 100 and 150, the feature shows users this new classification for atrial fibrillation with high heart rate.
And then it recommends anyone with this warning speak to their doctor and healthcare team about the finding.
Details around this new ECG improvement were first uncovered by Steve Moser from Macrumors.com
It is unclear if Apple is releasing the new and improved ECG functionality only in the US to start with. Or if Apple makes it available to countries/regions with previously approved ECG function when the new iOS / watchOS is released next week.
What we know is that the original ECG functionality is still getting approved in many countries, like South Korea and Japan.
Additionally, we anticipated that Taiwan will have the ECG feature available on the Apple Watch when Apple releases watchOS 7.2 and iOS 14.3.
The new incremental change in the Afib detection algorithms made by Apple is huge.
As other wearable players ( Samsung, Withings) are just beginning to catch up on ECG, Apple has gained momentum by adding new functionality.
