Use of a Smartwatch for Assessment of the QT Interval in Outpatients with Coronavirus Disease 2019

Figure 1:. Rhythm strips used for QTc measurement. These rhythm strips were obtained from the patient’s Apple Watch during the course of treatment. The QT and RR intervals are measured as shown and the QTc interval was calculated using Bazett’s formula.

Figure 2:. A: ECG obtained following the completion of treatment under home isolation. Note the consistency in the QT interval when measured in lead I or lead II (QT interval: 380 ms, RR interval: 690 ms, and QTc interval: 457 ms in both leads). B: Enhancement of lead I from the 12-lead ECG. C: Corresponding rhythm strip obtained from the Apple Watch after treatment, where a very similar waveform morphology and QT measurements as compared with lead I on the 12-lead ECG can be noted.