Accuracy of Wearable Monitors for Assessment of Heart Rate During Rest and Exercise

Wearable monitors have become ubiquitous, but their accuracy at assessing heart rate has been unclear. In the current analysis, researchers compared the accuracy of six common wearable monitors during exercise testing in 61 patients with normal sinus rhythm (NSR) and in 20 patients in atrial fibrillation (AF). They measured heart rates at rest and then during a treadmill test using both the wearable monitor and an electrocardiogram (ECG) monitor as the reference standard.

At rest, wearable devices showed reasonable accuracy; the mean absolute difference between ECG and wearable devices was 4.6 ± 8.4 beats per minute (bpm) in NSR and 7.0 ± 11.8 bpm in AF. At peak exercise, the difference was substantially larger: 13.8 ± 18.9 bpm in NSR and 28…