https://www.cnbc.com/2017/09/11/apple-watch-caridac-arrhythmia-tests-stanford-american-well.html

Apple is working with partners to test whether its smartwatch can be used to detect common heart conditions, an effort that would make its device a "must have" for millions of people worldwide.

The company is partnering up with a group of clinicians at Stanford, as well as telemedicine vendor American Well, to test whether Apple Watch's heart rate sensor can detect abnormal heart rhythms in a cohort of patients, according to two people familiar. The people requested anonymity as these plans have not yet been made public.