Credit: Danny Kim / TIME

In fact, Apple accompanied the launch of watchOS 5.2 with a press release, announcing that its ECG app and irregular rhythm notifications are now available in Hong Kong and 19 European countries, including France, Germany, Italy, Spain, and the U.K., after receiving CE clearance in the European Economic Area.

While the ECG feature is limited to the Apple Watch Series 4, Apple also adds that the lesser-known Irregular Heart Rhythm notification feature, which is supported on all watchOS 5 compatible Apple Watch models — everything except the original Series 0 — has also been expanded to the same list of countries, after also originally being restricted to users in the U.S. only.

The ECG feature is designed to capture heart rhythm on-demand when users are experiencing symptoms, allowing clinically useful data to be provided to their doctor, while the irregular rhythm notifications are actually the key component in detecting Atrial Fibrillation (AFib).

The heart rate sensors in the Apple Watch have been credited with saving lives even before Apple released the Series 4 model with its new ECG sensors and the improved heart rate monitoring in watchOS 5. Since then, the number of reports have only increased, with the ECG feature now being credited with even more successful diagnostics of potentially deadly conditions.

All of Apple’s Series 4 models of the Apple Watch have been manufactured with the necessary sensors to enable the ECG feature, however up until now the feature has been restricted to Apple Watch models sold in the U.S. via a combination of software limitations and device identifiers, meaning that users could only access these features if they originally purchased their Apple Watch in the U.S. While some evidence was found in the iOS 12.2 betas that Apple might tighten these restriction further with geofencing, it’s unclear whether that’s been implemented yet or not, however with the ECG feature now being available in 20 additional countries, it’s also possible that Apple’s choice to go with geofencing is intended to make it easier to guarantee that the feature is disabled in those countries where it’s still not available — something that may now particularly be a problem in mainland China.

Users updating to watchOS 5.2 in the newly-supported countries can enable the new heart features by opening the Health app on their accompanying iPhone, which should immediately present them with details about the new features, along with instructions on how to use them, how to interpret the results, and what to do if they’re feeling symptoms that require immediate medical attention. The feature also requires that users be using an iPhone 5s or later running iOS 12.2.

Meanwhile, despite this major expansion, Apple’s ECG and Irregular Heart Rhythm notifications features still remains unavailable in Canada, which is an interesting case since Apple has “communicated” that they are working to bring the ECG feature to Canada, yet Health Canada has stated publicly that Apple has yet to even file an application with the Canadian government. It’s even less clear how regulatory approvals are progressing in other countries where the Apple Watch is sold.