Elsevier

Heart Rhythm

Volume 18, Issue 9, September 2021, Pages 1482-1490
Heart Rhythm

Clinical
Validation of an algorithm for continuous monitoring of atrial fibrillation using a consumer smartwatch

https://doi.org/10.1016/j.hrthm.2021.03.044Get rights and content
Under a Creative Commons license
open access

Background

Consumer devices with broad reach may be useful in screening for atrial fibrillation (AF) in appropriate populations. However, currently no consumer devices are capable of continuous monitoring for AF.

Objective

The purpose of this study was to estimate the sensitivity and specificity of a smartwatch algorithm for continuous detection of AF from sinus rhythm in a free-living setting.

Methods

We studied a commercially available smartwatch with photoplethysmography (W-PPG) and electrocardiogram (W-ECG) capabilities. We validated a novel W-PPG algorithm combined with a W-ECG algorithm in a free-living setting, and compared the results to those of a 28-day continuous ECG patch (P-ECG).

Results

A total of 204 participants completed the free-living study, recording 81,944 hours with both P-ECG and smartwatch measurements. We found sensitivity of 87.8% (95% confidence interval [CI] 83.6%–91.0%) and specificity of 97.4% (95% CI 97.1%–97.7%) for the W-PPG algorithm (every 5-minute classification); sensitivity of 98.9% (95% CI 98.1%–99.4%) and specificity of 99.3% (95% CI 99.1%–99.5%) for the W-ECG algorithm; and sensitivity of 96.9% (95% CI 93.7%–98.5%) and specificity of 99.3% (95% CI 98.4%–99.7%) for W-PPG triggered W-ECG with a single W-ECG required for confirmation of AF. We found a very strong correlation of W-PPG in quantifying AF burden compared to P-ECG (r = 0.98).

Conclusion

Our findings demonstrate that a novel algorithm using a commercially available smartwatch can continuously detect AF with excellent performance and that confirmation with W-ECG further enhances specificity. In addition, our W-PPG algorithm can estimate AF burden. Further research is needed to determine whether this algorithm is useful in screening for AF in select at-risk patients.

Keywords

Atrial fibrillation
Atrial fibrillation burden
Photoplethysmography Remote monitoring
Screening
Smartwatch

Cited by (0)

Funding sources: This research was funded by a grant from Samsung to Dr Olgin (Principal Investigator). Drs Olgin, Pletcher, and Marcus are funded by National Institutes of Health Grant U2CEB021881. Disclosures: Dr Nathan, Dr Zhu, Jacob Kim, Dr Kuang, and Alex Gao are employees of Samsung Research America. All other author have reported that they have no relationships relevant to the contents of this paper to disclose. The entire study was performed by and all data (including from the smartwatch) were stored, managed, and analyzed by the UCSF team.