Apple Watch Series 4 will now help users in the US take an electrocardiogram (ECG) right from their wrist, capturing heart rhythm in a moment when they experience symptoms like a rapid or skipped heart beat and helping to provide critical data to physicians.

When left untreated, AFib is one of the leading conditions that can result in stroke, the second most common cause of death around the world.

Both the features are now available as part of a free update to watchOS 5.1.2.

“The role that technology plays in allowing patients to capture meaningful data about what’s happening with their heart, right when it’s happening, like the functionality of an on-demand ECG, could be significant in new clinical care models and shared decision making between people and their healthcare providers,” said Nancy Brown, CEO of the American Heart Association.