The ECG app and irregular rhythm notification feature can alert users to signs of AFib. Left untreated, AFib is one of the leading conditions that can result in stroke, the second most common cause of death around the world.



“We’ve seen the ECG app and irregular rhythm notifications on Apple Watch have meaningful impact on our customers across the United States,” said Jeff Williams, Apple’s chief operating officer. “We are excited to bring these features to customers in Europe and Hong Kong, giving them access to empowering information about their heart health.”

ECG App

New electrodes built into the back crystal and Digital Crown on Apple Watch Series 4 work together with the ECG app to enable customers to take an ECG similar to a single-lead electrocardiogram. Taking an ECG recording is as simple as launching the ECG app on Apple Watch Series 4 and touching the Digital Crown, which completes the circuit and allows electrical signals across the user’s heart to be measured. After 30 seconds, the ECG app can classify the user’s heart rhythm as AFib or sinus rhythm.