A new study from University of California, San Francisco, researchers shows that the Apple Watch can detect atrial fibrillation with high accuracy at least when wearers were at rest.
In the test of 1,620 people, researchers used a Cardiogram app to access heart-rate sensor data using the heart-rate sensor and step counter built into the Apple smartwatch. A deep neural network analyzed the heart rate data and step-count data, which was used to determine whether a person was active (explaining a sudden heart rate spike) or at rest.
The resulting algorithm was able to tell the difference between atrial fibrillation and normal heartbeats with about 97% compared to electrocardiograms. This data came from about 50 patients with atrial fibrillation who were undergoing procedures to restore their heart rates to normal.
Atrial fibrillation is an irregular and often rapid heart rate that can increase your risk of stroke, heart failure and other heart-related complications. During atrial fibrillation, the heart's two upper chambers (the atria) beat chaotically and irregularly — out of coordination with the two lower chambers (the ventricles) of the heart. Atrial fibrillation symptoms often include heart palpitations, shortness of breath and weakness.