Masked atrial septal defect in constrictive pericarditis.

The combination of an atrial septal defect (ASD) and constrictive pericarditis (CP) is rare and difficult to diagnose, since the signs of ASD may be masked by those of CP. We report a patient in whom the diagnosis was made by color Doppler echocardiography and magnetic resonance imaging (MRI), and confirmed by cardiac catheterization. Open heart surgery was successfully performed to close the defect.