Right ventricular function in infants with bronchopulmonary dysplasia: association with respiratory sequelae

Background: While cor pulmonale has been noted in infants with bronchopulmonary dysplasia (BPD), information on right ventricular (RV) function is limited. Objective: To assess RV function in infants with severe BPD and ascertain correlation with respiratory outcomes. Methods: We prospectively assessed RV function using tissue Doppler imaging (TDI), 2D fractional area change (FAC), M-mode tricuspid annular plane systolic excursion (TAPSE) and myocardial performance index (MPI) using echocardiography. Additionally, we compared RV function with preterm infants with no BPD. Results: Eighteen preterm infants with severe BPD were enrolled at 36 weeks' gestation. Higher E/E' (r = 0.78, p < 0.0001) and lower FAC (r = 0.8, p < 0.0001) showed strong correlations with the subsequent duration of respiratory support. Correlations with TDI isovolumic velocity and Tei index were significant (-0.69, p = 0.002 and 0.58, p = 0.011, respectively). On comparison with infants with no BPD, TDI peak systolic velocities (0.06 ± 0.01 vs. 0.09 ± 0.01 m/s, p < 0.0001), peak isovolumic systolic velocities (0.05 ± 0.009 vs. 0.07 ± 0.008 m/s, p < 0.0001) and RV FAC (31 ± 4.7 vs. 36 ± 3.6%, p = 0.019) were significantly lower. Cardiac relaxation was impaired [higher TDI E/E' ratio (9.6 ± 1.8 vs. 5.2 ± 0.5, p < 0.0001) and higher RV MPI (0.33 ± 0.03 vs. 0.25 ± 0.03, p < 0.0001)]. Conclusions: Impaired RV performance in the infants with severe BPD at 36 weeks' corrected gestation correlated with a longer duration of subsequent respiratory support.