A rare case of inferior venacaval type of atrial septal defect in an adult: Echocardiographic features

We report a rare type of atrial septal defect with communication between the left atrium and the inferior vena cava. This type of defect has been referred to as a low sinus venosus type of atrial septal defect because of its developmental origin, and possibly is caused by defective absorption of the left venous valve of the sinus venosus into the septum secundum. Detailed echocardiographic features are discussed.