Unusual Hemodynamic Changes in an Infant with a Restrictive Ventricular Septal Defect

A 7-month-old asymptomatic infant was known to have a restrictive membranous ventricular septal defect partially closed by an aneurysm of the membranous septum. At 13 months of age, he developed unexpected pulmonary hypertension, with no clinical sign of cardiac failure. Cardiac catheterization assessed the pulmonary artery pressure at a systemic level with significant left-to-right shunt. After surgical closure, the pulmonary arterial pressure decreased by 50%. We suspect an enlargement of the ventricular septal defect caused by the rupture of the aneurysm of the membranous septum—a rare complication.