(Pocket-lint) - Apple's electrocardiogram (ECG in the UK or EKG in the US) reading feature for Apple Watch Series 4 owners has gone live in the UK and Europe.

Apple previously launched this ECG functionality in the US last December, months after teasing it as a marquee Apple Watch Series 4 feature. The company had promised at the time that it would come to UK and more countries in Europe, and now it has, via a watchOS 5.2 update. Apple said the ECG app has been "CE marked and cleared in the European Economic Area".

Here's a list of the newly supported countries:

  • UK
  • Austria
  • Belgium,
  • Denmark
  • Finland
  • France
  • Germany
  • Greece, Guam
  • Hong Kong
  • Hungary
  • Ireland
  • Italy
  • Luxembourg
  • Netherlands
  • Norway
  • Portugal
  • Puerto Rico
  • Romania
  • Spain
  • Sweden
  • Switzerland

Owners of the Apple Watch Series 4 can take an ECG reading using the Health app on their iPhone. First, they must open up the ECG app on the Watch and place their index finger on the crown. The Apple Watch will then take the ECG and heart rhythm and save it in the Apple Health app on the iPhone. Users can then export an PDF report with the results to send to their doctor.

You can read more about how ECG works from here. Keep in mind the AF Association estimated there are around 1.5 million people in the UK living with atrial fibrillation, and a third of these people may be unaware. That's where the latest Apple Watch comes in handy. It has electrodes built into the back crystal and Digital Crown that work together with the ECG app to take a reading.

Additionally, Apple has also aded an irregular heart rhythm notification feature for all Series 1 through to Series 4 Apple Watch users that will help them identify signs of AFib, the most common form of irregular rhythm. If the watch does pick up something on the 2-hourly test, it will test another five times in quick succession and then alert you to the fact. If you are wearing a Series 4 Apple Watch it will prompt you to perform an ECG test. 

The new WatchOS 5.2 update also brings new Hermes watch faces and various bug fixes and security improvements. You can download the software through the Apple Watch app on an iPhone.

For more specific update instructions, see this Apple support page.

Writing by Maggie Tillman.