Atrial fibrillation is a health condition that often goes undiagnosed, so ECG app and heart rhythm alerts on Apple Watch are highly useful for detecting early signs of disease. ECG readings also normally require a full ECG machine and a visit to the doctor, which is far less convenient than a reading taken with the Apple Watch.

The irregular rhythm notification feature intermittently checks heart rhythm in the background and sends a notification if an irregular heart rhythm is identified that could potentially be atrial fibrillation (AFib). Upon receiving a notification, users in territories where the feature is approved can immediately launch the ECG app and perform a more comprehensive test in just 30 seconds by placing their finger on the Digital Crown to generate an ECG waveform.

Apple has designed two algorithms that Apple Watch uses to measure electrocardiogram (ECG) waves. The second algorithm improves upon the first, by allowing the ECG app to check for atrial fibrillation (AFib) at higher heart rates - during exercise, for example. However, because of regulations in your country or region, version 2 might not be available to you. You can verify which version of the irregular rhythm notification feature you have on your Apple Watch or iPhone by following these steps.

The version number of the irregular rhythm notification is listed next to Feature Version.

Get weekly top MacRumors stories in your inbox.

When will iOS 16 and iPadOS 16 be released? Here's everything we know.

Apple on July 20 released iOS 15.6 and iPadOS 15.6, bringing improvements to the live sports experience in the TV app and several bug fixes.

Apple Watch SE or Apple Watch 7 - which one to get?

New iPhones are out. Which one should you buy?

Apple is already working on the next-generation versions of iOS 16 and iPadOS 16.

All we know about the next mainstream iPhone models.

Apple's next high-end iPhone lineup.

4 hours ago by Tim Hardwick

4 hours ago by Tim Hardwick

4 hours ago by Tim Hardwick

4 hours ago by Tim Hardwick

4 hours ago by Tim Hardwick

MacRumors attracts a broad audience of both consumers and professionals interested in the latest technologies and products. We also boast an active community focused on purchasing decisions and technical aspects of the iPhone, iPod, iPad, and Mac platforms.