Functional critical aortic stenosis with transient retrograde flow in a neonate with left diaphragmatic hernia.

We report a neonate with left congenital diaphragmatic hernia and severe left ventricular dysfunction, in whom the blood flow in the transverse arch and its branches was supported in a retrograde fashion by patent ductus arteriosus. There was only minimal antegrade flow across the aortic valve and hemodynamic physiology resembled critical aortic stenosis, necessitating the immediate use of prostaglandin E1 infusion to maintain the patent ductus arteriosus.