Normal atrial septum. Transoesophageal 3DE view of the normal atrial septum viewed from the right atrial aspect. The orientation of the image is anatomic so the superior vena cava and inferior vena cava are shown uppermost and lowermost on the image respectively. This image was acquired by 3D TOE using a full-volume acquisition over four cardiac cycles. The asterisk marks the margins of the oval fossa. SVC, superior vena cava; IVC, inferior vena cava; TV, tricuspid valve; CS, coronary sinus.