Double Atrial Septum with Persistent Interatrial Space: Echocardiographic Features of a Rare Atrial Septal Malformation

We describe the echocardiographic features of 4 new cases of a rare atrial septal malformation consisting a double atrial septum with a midline chamber between the left and right atrium. Half of the cases had major left-sided obstructive lesions. Transthoracic, transesophageal, intracardiac, and fetal echocardiographic features of this anomaly are demonstrated. Previous descriptions, embryologic speculations, and clinical considerations are discussed.