Apple has released watchOS 5.2.1 update, which brings the ECG app. It can monitor heart activity as well as a single-channel ECG – but you must be at least 22 years old to use the program.
The app uses electrodes in the Digital Crown and the back panel for ECG. At the first launch, the application warns that it is not capable of detecting heart attacks – but it can potentially detect symptoms of atrial fibrillation and some other abnormalities. Data from the ECG app is synchronized with the Health app at iPhone with firmware iOS 12.1.1. Important: the application is not compatible with the beta version iOS, even if you have already downloaded the latest update.
It's unclear why the developers introduced an age limit. It's not hard to get around it – just change your date of birth in the Health app – but we don't recommend that you do that.
However, the ECG app is available on Apple Watch Series 4 with watchOS 5.1.2 paired with iPhone 5s or newer with iOS 12.1.1 on board . So far, this function works only on the American version of the watch – but it does not depend on the region installed in the smartphone and watch, so on American Apple Watch 4 the application will start even from Russian accounts without any additional measures.
Note that ECG readings obtained in this way require further consultation with a specialist. In the Health app at iOS, you can easily save the results as PDF to show them to your doctor.