Rosemary Stiles, a native of Kentucky has credited her Apple Watch from saving her as it detected AFib while she was sleeping.

Rosemary mentioned that prior to the notification she would feel ‘run down’, and would often doze after sitting down in short while. Rosemary had no idea then that it was symptoms of atrial fibrillation.
Her Apple Watch showed an alert one day that prompted Rosemary to seek medical attention at the Norton Hospital. In an interview with the local news outlet WHAS11, registered nurse Tara Mudd stated that Rosemary was the first person to come to the hospital with atrial fibrillation detection.
When the Apple Watch detects an irregular heartbeat, it sends out an alert to the user that he or she might be experiencing atrial fibrillation. Furthermore, the Apple Watch user is instructed to consult with their doctors if the condition hasn’t been diagnosed before.