Figure 7.

Types of interatrial communications. (A) The most common form of interatrial communication is at the site of the oval fossa making it a true atrial septal defect (ASD). The superior (Sup) and inferior (Inf) sinus venosus (SV) defects, coronary sinus (cs) defects, and atrioventricular septal defects (AVSD) are outside the atrial septum although they permit interatrial shunting; (B) an enface view of a fenestrated oval fossa defect. CS, coronary sinus; ICV, inferior caval vein; SCV, superior caval vein; TV, tricuspid valve.