CNET senior reporter Vanessa Hand Orellana sits in a consultation room at UCSF Medical Center in San Francisco while cross-referencing Apple Watch's new electrocardiogram feature readings with medical-grade EKG equipment.
"The last thing I expected was to find something abnormal with my heart rhythm," she says.
With the update to WatchOS 5.1.2, heart rate will play a more important role on the Apple Watch as the device gets access to the two new FDA-cleared features: an abnormal heart rhythm alert for all models, except for the first-generation, and an electrocardiogram (EKG or ECG) exclusive to the Series 4.
The EKG on the Apple Watch directly coincided with the results of the hospital EKG that Dr. Gregory Marcus, a professor of medicine and a cardiac electrophysiologist at UCSF Medical Center, had printed out. Both devices showed intermittent early beats coming from the upper right ventricle of Vanessa's heart.