Apple Heart Study app launches in the US in partnership with Stanford Medicine

Apple has launched Apple Heart Study, a research study app that uses Apple Watch’s heart rate sensor to collect data on irregular heart rhythm, in partnership with Stanford Medicine. The app also notifies users who may be experiencing atrial fibrillation (AFib), with additional monitoring. The Apple Heart Study was announced back in September and is now available to Apple Watch users in the US.

AFib, the leading cause of stroke, is responsible for approximately 130,000 deaths and 750,000 hospitalizations in the US every year. Many people don’t experience symptoms, so AFib often goes undiagnosed.

Apple explains how the Apple Watch is used in the research study:

To calculate heart rate and rhythm, Apple Watch’s sensor uses green LED lights flashing hundreds of times per second and light-sensitive photodiodes to detect the amount of blood flowing through the wrist. The sensor’s unique optical design gathers signals from four distinct points on the wrist, and when combined with powerful software algorithms, Apple Watch isolates heart rhythms from other noise. The Apple Heart Study app uses this technology to identify an irregular heart rhythm.

If an irregular heart rhythm is identified, users will receive a notification, of course, on their Apple Watch and iPhone alongside consultation with a study doctor for free, and an electrocardiogram (ECG) patch for more in-depth monitoring. The research study program is open to Apple Watch users (Series 1 or later) who are 22 years or older. The Apple Heart Study app is available in the US App Store and is limited to US residents — for now.