Functional pulmonary atresia in neonatal Marfan's syndrome: successful treatment with inhaled nitric oxide.

Functional pulmonary atresia is characterized by a structurally normal pulmonary valve not opening during right ventricular ejection. We report this rare condition in a premature newborn of a twin pregnancy, in which fetal echocardiography findings were consistent with critical pulmonary stenosis. After birth, features of neonatal Marfan's syndrome were noted. Echocardiography showed a morphologically normal but immobile pulmonary valve with continuous regurgitation. Right ventricular pressure was subsystemic. In this case, initial treatment with nitric oxide, followed by pharmacological duct closure, was successful. Differentiating between anatomic and functional pulmonary valve atresia may be difficult. The echocardiographic criteria are discussed.