Myocardial strain on admission predicts disease severity in infants hospitalized for bronchiolitis

Objective: To assess cardiac function in infants with bronchiolitis and the association with disease severity and outcomes.

Working hypothesis: Cardiac function may be impaired in bronchiolitis and represent an early predictor of disease severity.

Study design: A prospective cohort study.

Patient selection: Infants with suspected bronchiolitis were included.

Methodology: All cases received antigen detection and viral genome detection from nasal lavage or swabs and echocardiography within 24 hours from admission. Systolic and diastolic function in left ventricle (LV) and right ventricle (RV) were assessed using longitudinal strain (LS), a measure of myocardial deformation. Pulmonary artery pressures were estimated using tricuspid regurgitation jet (TR), when present, and end-systolic eccentricity index (EI ES). Main outcomes (duration of respiratory support, length of stay [LOS], and type of respiratory support) were collected. Data were compared to normative existing data, and a group of healthy infants, matched in age.

Results: Twenty-eight infants with bronchiolitis and 10 healthy comparators were included. Cases with bronchiolitis showed significantly lower values of RV LS and LV LS compared to healthy comparators (LV: p0.04 and RV: P < .001). Ten infants (36%) had a normal biventricular function, nine (32%) had LV impairment, and nine (32%) had a biventricular impairment. No significant differences were found in TR and EI ES. Infants with biventricular impairment demonstrated a significant increase in LOS (p0.04) and higher levels of respiratory support compared to the healthy comparators (P = .03).

Conclusions: Bronchiolitis is associated with myocardial impairment. Cardiac function is related to disease severity and outcome.