A-fib--a Rapid, Irregular Heartbeat--Can Kill You, but New Tech Can Spot It

A fluttering heartbeat called A-fib can lead to stroke, but smartwatches can detect it, and there are good treatments

https://www.scientificamerican.com/article/a-fib-a-rapid-irregular-heartbeat-can-kill-you-but-new-tech-can-spot-it/