Apple today released the watchOS 5.2.1 update which brought a brand-new ECG app for taking heart rate measurements that are not dissimilar from those recorded with a single-lead electrocardiogram, but you must be 22+ years old to use it.
It uses electrodes in the Digital Crown and the back crystal to measure a heart’s electrical activity and determine the presence of atrial fibrillation (AFib) or sinus rhythm on a classifiable waveform (one thing it cannot do is check for signs of a heart attack). ECG waveforms generated by the app are synced securely to the Health app on iPhone with iOS 12.1.1.
From there, any ECG waveform can be easily shared with your clinician. How to use ECG feature on your Apple watch?
Third-party apps like Heart Analyzer help you make sense of your ECG readings
We’re unsure as to why the Cupertino technology giant has imposed an age restriction on the ECG app, but suffice it to say that you could cheat quite easily by changing your birth date in the Health app. The onboarding process also puts up a warning screen for anyone under the age of 22, saying that the app is not intended for use by them.