The Apple Watch heart rate feature you probably didn't realize existed - Engadget

It can do more than track your heart rate during workouts The Apple Watch has such an extensive collection of features that it's easy for some to get lost in the shuffle, including one that can help you more closely monitor your heart health: a dedicated ECG app. Short for electrocardiogram, the feature allows for more in-depth analysis on your ticker than the baseline BPM monitor included in the device. Most modern Apple Watches have this feature, and it's never a bad idea to take some readings from time to time. The frequency at which your Apple Watch logs your heart rate varies based on your activity. During a workout, it does so constantly, but otherwise the only official detail given by Apple is that the time between these measurements "will vary" based on your activity unless you check it manually through the Heart Rate app. These measurements on their own can only tell you when your heart rate is too fast or slow; an ECG, on the other hand, measures the electrical signals from your heart, tracing each stage of each beat as it moves through the organ and painting a much more detailed picture. While an ECG does give a deeper look at how your heart is doing, it's important to n