Katherine Ellen Foley:

The new Apple Watch, however, has the equivalent of one lead on your wrist, the company’s website says. “The tech that Apple is working with is very rudimentary compared to what we’d do for someone in a hospital or health care setting,” Moore said. Although the watch can detect changes in the patterns of a person’s heart rate, these changes really only show a user if she has a heart rate that is too fast, too slow, or beating irregularly—signifying AFib. The watch won’t necessarily give the full picture a doctor would need to diagnose a medical issue […]

Apple got two FDA clearances through a “de novo” pathway, meaning it had to use data to show that its device worked, and that it was safe. For the ECG clearance, the FDA reviewed a study conducted by Apple and Stanford University in California. This study, called the Apple Heart Study included 588 individuals, half of whom had AFib and the other half of whom were healthy. The app was able to identify over 98% of the patients who had AFib, and over 99% of patients that had healthy heart rates. Cardiologists were able to read 90% of the total readings, although about 10% of them were unreadable.

I’m no doctor but those results look pretty impressive.