Fitbit has begun rolling out an update that adds atrial fibrillation notifications for nine of its recent fitness trackers and smartwatches. While Fitbit has received approval from the FDA to roll out the feature, it is only available in the US, at least for the time being.
https://www.notebookcheck.net/Nine-Fitbit-fitness-trackers-and-smartwatches-will-now-warn-of-atrial-fibrillation-after-new-update.615647.0.html