The Clinical Utility of Relative Bradycardia for Identifying Cases of Coronavirus Disease 2019 Pneumonia: A Retrospective Pneumonia Cohort Study.

Objective Both coronavirus disease 2019 (COVID-19) pneumonia and relative bradycardia are common conditions among clinicians; however, the association between these has not been well studied. The present study assessed whether or not relative bradycardia on admission was more predominant in patients with COVID-19 pneumonia than in those with other infectious pneumonia. Methods For this single-center, retrospective cohort study, we collected data through electronic medical records and examined the occurrence of relative bradycardia on admission. We used logistic regression analyses to compare outcomes with and without relative bradycardia on admission. The primary outcome was COVID-19 pneumonia. The secondary outcome was hypoxemia during the hospital stay. We performed multivariable regression with adjusting for the effects of age, sex, healthcare-associated pneumonia, body mass index, Charlson comorbidity index, and bilateral infiltration on computed tomography (CT) as confounding factors. Patients Adult patients with new-onset hospitalized infectious pneumonia confirmed by CT between January 1, 2020, and July 31, 2021. Results This study included 395 participants. On admission, 87 (22.0%) participants exhibited relative bradycardia, and 302 (76.5%) participants had COVID-19. Relative bradycardia on admission was not significantly associated with COVID-19 pneumonia [adjusted odds ratio (OR) 1.32; 95% confidence interval (CI) 0.49-3.54, p=0.588] but was associated with hypoxemia (adjusted OR 4.74; 95%CI 2.64-8.52, p<0.001). Conclusion The study results showed that relative bradycardia on admission was not associated with COVID-19 in cases of infectious pneumonia. However, relative bradycardia may be associated with the incidence of hypoxemia in pneumonia.

Relative bradycardia in patients with moderate-to-severe COVID-19: a retrospective cohort study.

Coronavirus-related disease (COVID-19) can result in relative bradycardia; however, there are no reports on relative bradycardia in patients with moderate-to-severe COVID-19 who require oxygen. We retrospectively investigated 45 patients with moderate-to-severe COVID-19 and examined the relationship between heart rate and body temperature at the time of initiating oxygen or mechanical ventilation. For three consecutive days after initiating oxygen therapy, body temperature (day's highest temperature), heart rate, and other vital signs were measured simultaneously. We checked for relative bradycardia and analyzed the differences between patients with moderate COVID-19 (oxygen requirement ≤ 5 L/min) and those with severe COVID-19 (oxygen requirement ≥ 5 L/min). Of the 45 patients, 28 and 17 had moderate and severe COVID-19, respectively. The heart rate increased with increasing body temperature, and almost all patients satisfied the criteria of relative bradycardia. In Spearman's rank correlation analysis, body temperature was significantly correlated with heart rate (ρ = 0.483, p = 0.012) in moderately ill patients but not in severely ill patients (ρ = 0.261, p = 0.297). Multiple regression analysis revealed that the severity of COVID-19 and body temperature were independent predictors of heart rate. The predicted change in heart rate was 6.0 beats/min for each 1 °C rise in body temperature. Relative bradycardia was suggested to be a characteristic finding in patients with moderate-to-severe COVID-19 who require oxygen. Additionally, severely ill patients were more likely to develop relative bradycardia than moderately ill patients. Focusing on the relationship between heart rate and body temperature might help clinicians diagnose this disease in patients with worsening respiratory failure.

Relative bradycardia as a clinical feature in patients with coronavirus disease 2019 (COVID-19): A report of two cases.

We treated two patients with COVID-19 pneumonia requiring mechanical ventilation. Case 1 was a 73-year-old Japanese man. Computed tomography (CT) revealed ground-glass opacities in both lungs. He had severe respiratory failure with a partial pressure of oxygen in arterial blood/fraction of inspiratory oxygen ratio (P/F ratio) of 203. Electrocardiogram showed a heart rate (HR) of 56 beats/min, slight ST depression in leads II, III, and aVF, and mild saddle-back type ST elevation in leads V1 and V2. High-sensitivity cardiac troponin T (cTnT) level was slightly elevated. Despite a high fever and hypoxemia, his HR remained within 50-70 beats/min. Case 2 was a 52-year-old Japanese woman. CT revealed ground-glass opacities in the lower left lung. Electrocardiogram showed a HR of only 81 beats/min, despite a body temperature of 39.2 °C, slight ST depression in leads V4, V5, V6, and a prominent U wave in multiple leads. She had an elevated cTnT and a P/F ratio of 165. Despite a high fever and hypoxemia, her HR remained within 50-70 beats/min. Both patients had a poor compensatory increase in their HR, despite their critical status. Relative bradycardia could be a cardiovascular complication and is an important clinical finding in patients with COVID-19. .

Relative Bradycardia in Patients with Mild-to-Moderate Coronavirus Disease, Japan.

Coronavirus disease is reported to affect the cardiovascular system. We showed that relative bradycardia was a common characteristic for 54 patients with PCR-confirmed mild-to-moderate coronavirus disease in Japan. This clinical sign could help clinicians to diagnose this disease.