(Pocket-lint) - When it launched the Apple Watch Series 4 in September, Apple dwelled for some time on the new wearable's electrocardiogram (ECG) feature. Now it's available in the US, as part of the WatchOS 5.1 update released Tuesday 20 October, but sadly nowhere else.

That's because the only agency to approve the use of the ECG functionality to monitor heart rhythm is the US Food and Drug Administration (FDA). Until other regional bodies approve that feature, it cannot be activated in those countries.

But, there is a way to unlock it anywhere. And it's remarkably simple.

Apple-centric website 9to5Mac previously found on a beta version of the next WatchOS that the ECG app (EKG, as it is called in the States) works when the region (not language) is set to the US - regardless of the device's actual location.

That means you can get it working by just heading to your iPhone's Settings (the iPhone paired with the Watch), then General > Language & Region and choosing United States as the region.

It will change several features on your phone itself, such as time and date format, but will ensure you can use the ECG function no matter where you live. You can always then reset the region afterwards.

This seems to work fine on the build 9to5Mac used, but we are lead to believe it works on the full WatchOS 5.1 software too.

Writing by Rik Henderson.