Relative bradycardia in patients with COVID-19

Introduction: Relative bradycardia(RB) is a relatively low heart rate response to rise in body temperature that occurs in several infectious diseases and can be an important clinical sign. In previous case reports, RB was presented in some patients with COVID-19. Objective and Methods: To investigate the correlation between temperature and heart rate, we retrospectively reviewed 249 febrile patients with documented COVID-19 patients. RB was defined as a rise in the heart rate (HR) from a basal HR of less than 10 beats/minute/°C rise in temperature. Results: In this study, the prevalence of RB in patients with COVID-19 was 60.6%. When the HR at peak temperatures for patients with COVID-19 were compared with reference valve (general temperature-heart rate response in infectious disease), our findings demonstrate a relatively lower heart rate at all peak temperatures recorded. Despite differences in HR response, there were not significant differences in clinical outcomes (pulmonary manifestation, ICU care, Death). Conclusion: Most patients with COVID-19 are associated with relative bradycardia, not related to clinical outcomes. RB in COVID-19 can be considered as the clinical features for differential diagnosis from other febrile conditions.