Evaluation of infants with bronchopulmonary dysplasia using cardiac catheterization

Nine infants with bronchopulmonary dysplasia underwent cardiac catheterization to define thier circulatory status. In room air, the mean cardiac index was normal (3.4 liters/min/sq m), but pulmonary arterial pressure (39 mm Hg, mean) and pulmonary vascular resistance (8.6 Wood units . sq m) were elevated. Preejection period/right ventricular ejection time ratios determined echocardiographically correlated well with values obtained at catheterization, but did not correlate well with hemodynamic values. Administration of 40% and 88% oxygen caused variable responses in hemodynamic measurements. Studies of left ventricular function were normal in all patients. These findings raise questions about the long-term prognosis of infants with bronchopulmonary dysplasia.