It often takes months for a COVID-19 patient’s resting heart rate (RHR) to return to normal, according to a new analysis published in JAMA Network Open.
The study’s authors explored wearable data from more than 37,000 participants enrolled from March 25, 2020, to Jan. 24, 2021.
“Previous studies have found that wearable data can improve real-time detection of viral illness or discrimination of individuals with COVID-19 vs other viral infections,” wrote lead author Jennifer M. Radin, PhD, MPH, a specialist at San Diego’s Scripps Research Translational Institute, and colleagues. “Wearable devices provide a way to continuously track an individual’s physiological and behavioral metrics beginning when healthy (i.e., before infection), during the course of infection and recovery back to baseline.”
Nearly 900 of the study’s participants underwent a COVID-19 test after reporting COVID-like symptoms, and 27% tested positive. The mean age of patients testing positive for COVID-19 was 45.3 years old, and 70.9% were women. The mean age of patients with a negative test was 44.7 years old, and 71.1% were women.
Looking closely at RHR data, Radin et al. found that patients with a confirmed COVID-19 diagnosis experienced “a transient bradycardia followed by a prolonged relative tachycardia that did not return to baseline, on average, until 79 days after symptom onset.”
“Step count and sleep quantity returned to baseline sooner than RHR at 32 and 24 days, respectively,” the authors added. “During recovery, individuals with COVID-19 experienced different trajectories in the return of their RHR to their normal compared with COVID-negative individuals. A small subset of COVID-positive participants (32 participants) maintained an RHR more than 5 beats per minute greater than their baseline RHR that did not return to their normal for more than 133 days.”
In addition, the group wrote, individuals with a confirmed COVID-19 diagnosis were more likely to experience frequent coughing, body aches and shortness of breath than the COVID-19-negative group.
“We found a prolonged physiological impact of COVID-19 infection, lasting approximately two to three months, on average, but with substantial intraindividual variability, which may reflect various levels of autonomic nervous system dysfunction or potentially ongoing inflammation,” the group concluded. “Transient bradycardia has been noted in a case study approximately 9 to 15 days after symptom onset, which was also seen in our population. Our data suggest that early symptoms and larger initial RHR response to COVID-19 infection may be associated with the physiological length of recovery from this virus.”
Read the full research letter in JAMA Network Open here.