Benign outcome of pulmonary hypertension in neonates with a restrictive patent foramen ovale versus result for neonates with an unrestrictive patent foramen ovale.

Premature closure or restriction of foramen ovale (FO) is a rare but known entity. FO diameter <2 mm and Doppler velocity >120 cm/s, diameter <3 mm with Doppler velocity measured gradient >5 mmHg have all being used by various authors to describe this entity. Some neonates with restrictive FO have been noted to have severe pulmonary hypertension with no clinical signs or symptoms and with spontaneous resolution without any intervention. Seven consecutive neonates were indentified in the database between 01/01/2003 and 06/30/2010 with diagnosis of restrictive PFO (diameter <2 mm) with structurally normal heart and their initial and follow-up echocardiogram as well as hospital medical records were reviewed. As a control, seven neonates with diagnosis of pulmonary hypertension and respiratory distress syndrome or meconium aspiration syndrome were randomly selected. Eighty-six percent of the patients in the control group were symptomatic and required treatment as compared to 14% in the restrictive FO group (p = 0.03). Further, the fall in the peak instantaneous pulmonary artery pressure on follow-up echocardiogram was greater in the restrictive FO group compared with the non-restrictive group (p = 0.03). Patients with pulmonary hypertension and a restrictive FO with no other associated congenital heart disease and/or lung pathology behave differently when compared to neonates with non-restrictive FO and pulmonary hypertension with associated lung disease. They seldom manifest symptoms requiring intervention and tend to show a faster drop in their pulmonary artery pressure toward the normal.