JMIR Publications

ABSTRACT

Background:

Recent studies have linked a low Heart Rate Variability (HRV) with COVID-19 infection [1–6], indicating that this parameter can be a marker of the onset of the disease, its severity, and predictor of mortality in infected people. Given the large offer of wearable devices that capture physiological signals of the human body easily and non-invasive, several studies used this equipment to measure the HRV of individuals and related these measures to the infection by COVID-19.

Objective:

The aim was to determine the effectiveness of HRV measures from wearable devices as predictors of the onset and worsening of symptoms in patients infected with COVID-19.

Methods:

A systematic review was conducted, searching the following databases up to the end of October 2022: Embase, PubMed, Web of Science, Scopus, and IEEE. Studies had to include (I) measures of HRV in patients with COVID-19, (II) measurements involving the use of wearable devices, and (III) the changes in HRV were related to COVID-19 disease. The main result was the association of low HRV with the onset of COVID-19 and worsening of symptoms, in some cases was possible to predict the onset of this disease before a clinical positive test. We also conducted a meta-analysis of these measures to reduce the possible biases and increase the statistical power of the primary research.

Results:

The meta-analysis of studies reported shows that a reduction in HRV parameters is associated with COVID-19 infection. The decrease in SDNN index was -25.8 ms (95% CI -35.01, -16.62) when compared individual baselines of participants during healthy time versus infection time, and -2.09 ms (95% CI -4.88, 0.71) when this comparison uses the mean baseline of all participants. For the RMSSD index, the results are similar, with a reduction of -18.81 ms (95% CI -28.04, -9.57) when comparing individual baselines of participants between healthy and infection time. The unique study that compared using a mean baseline of participants before or after COVID-19 infection found no significant reduction.

Conclusions:

Wearable devices that measure changes in HRV, such as smart watches, rings and bracelets, provide information that allows identifying the COVID-19 infection during the presymtptomatic period as well as its worsening, through an indirect and non-invasive self-diagnosis. Clinical Trial: The protocol for this review was registered in the International Prospective Register of Systematic Reviews (PROSPERO; CRD42023399705)