Background

Bronchiolitis is the most frequent cause of admission to the pediatric intensive care unit (PICU). Though extra-pulmonary manifestations have been previously studied, myocardial dysfunction has not yet been well defined.

Objectives

The aim of this study was to assess cardiac function in patients hospitalized with bronchiolitis.

Methods

Infants (0-12 months) hospitalized with bronchiolitis between January and March 2019 were included in this prospective, observational study. Previous cardiopathies were considered exclusion criteria. Echocardiography was performed within 48 hours of admission. Measurements of right ventricle (RV) and left ventricle (LV) systolic and diastolic function as well as cardiac output were analyzed. Data obtained were compared with healthy age-matched controls (n=22).

Results

Forty-three children were enrolled in the study (median age 3.6 months). Fifteen (34%) required admission to the PICU for positive pressure and three mechanical ventilation.

Patients requiring PICU support had significant RV systolic dysfunction, with diminished mean TAPSE (10.3±1.8 vs. 12.5±2, p=0.001) and s'tricuspid Tissue Doppler Index (TDI) values (8.9±2 vs. 10.4±1.6, p=0.029) compared with mild cases of bronchiolitis. LV diastolic dysfunction was also found in this group, with lower mean e'mitral TDI values (8.2±3.4 vs. 9.8±3.1, p=0.02) and increased E/e'mitral ratios (10.8±3.1 vs. 9.3±2.9, p=0.06). There were no significant differences between controls and patients with mild bronchiolitis.

Conclusion

In addition to expected RV systolic dysfunction, patients with severe bronchiolitis have altered LV diastolic function, possibly due to direct viral cardiac involvement. Confirmation of these results in further studies encompassing larger series could help optimize ICU hemodynamic management of severe bronchiolitis.