Alphabet-owned company Verily has received FDA certification for its Study Watch. As one of Alphabet's many companies, which includes Google, it gives us a pretty good idea of the capabilities of Google's rumored Pixel Watch.
https://www.notebookcheck.net/FDA-ECG-approval-for-Alphabet-Watch-and-Google-s-recent-Fossil-deal-hint-at-smartwatch-plans.396586.0.html