Common wearable devices demonstrate variable accuracy in measuring heart rate during supraventricular tachycardia

Wearable devices are used as a noninvasive method of monitoring health. The accuracy of wearables for heart rate (HR) monitoring has been extensively studied in sinus rhythm, but evidence for tachyarrhythmias, particularly supraventricular tachycardia (SVT), is sparse.

The purpose of this study was to examine the accuracy of 4 common wearable devices-Apple Watch, Fitbit Charge HR, Garmin VivoSmart HR, and Polar A360-in measuring HR during paroxysmal SVT.

Data were gathered from 52 patients by placing 1 device on each wrist during an electrophysiological study at which SVT was induced. The device-measured HR was obtained by using the highest HR measured by the device during each SVT episode. This HR was compared with measurements from a 12-lead electrocardiogram (ECG), for which the rate during the last 5 seconds of SVT was averaged.

For SVT episodes <15 seconds, the Apple, Fitbit, Garmin, and Polar devices registered an increase from baseline HR in 18.7%, 19.5%, 1.5%, and 37.7% of episodes, respectively. For episodes 15-60 seconds, the Apple, Fitbit, Garmin, and Polar devices registered an increase in 67.6%, 42.4%, 24.3%, and 65.5% of episodes, respectively. For episodes ≥60 seconds, the Apple and Polar devices had 23 of 23 and 19 of 21 episodes with at least 90% agreement between device-measured and ECG-measured HR, whereas the Fitbit and Garmin devices had 7 of 20 and 8 of 22 episodes with at least 90% agreement.

All wearable devices are inaccurate for short-duration SVT. Some devices are accurate for longer duration SVT.