ACE and bronchopulmonary dysplasia: 2008). While these infants were assessed by invasive cardiac catheterizations (a modality not widely available and possibly not without significant risks), vascular morphology and dynamics (the primary site of action of ACE inhibition) were not evaluated. Our study builds on this data using bedside ECHO assessments of LV function and vascular biomechanics. LV hypertrophy has been previously reported in infants with severe BPD (Mourani et al. 2008; Sehgal et al. 2016a,b,c).