Magnetic resonance imaging of a restrictive atrial septal defect in a univentricular connection.

Magnetic resonance imaging (MRI) provides accurate and valuable information regarding cardiac shunts including their location, size, and flow. We describe the MRI findings of a restrictive atrial septal defect within a complex case of congenital heart disease: univentricular atrioventricular connection of left ventricular type with right-sided discordant atrioventricular connection (single), absent left atrioventricular connection, and ventriculoarterial discordance. Few similar cases are reported in the literature. Magnetic resonance imaging may add valuable information regarding restrictive atrial shunts in univentricular hearts.