The clinical profile of the newborn with persistent pulmonary hypertension. Observations in 19 affected neonates.

In 19 neonates with severe cyanosis, normal chest x-rays, anatomically normal hearts, and a high incidence of perinatal complications, the clinical course was characterized by variable sustained cyanosis. Cardiac catheterization data showed high systemic or suprasystemic pulmonary artery pressure with right to left intracardiac shunting via the foramen ovale and ductus arteriosus. Arterial oxygen tension at an inspired oxygen concentration above 65% was helpful in distinguishing these patients from those with congenital heart disease, and for predicting prognosis.