3D TOE assessment of PFO. (A) 2D Mid-oesophageal bicaval view, showing a PFO with left-to-right shunt. (B) 3D-TEE zoomed volume for the IAS from the Rt. Atrial side showing no defect. (C) 3D-TEE zoomed volume for the IAS from the Lt. Atrial side showing a small defect during stretching of the PFO.