Fig. 1

Normal left atrial appendage (LAA) anatomical structures as visualized by two dimensional (2D) transesophageal echocardiography (TEE). AThick pectinate muscle at the apex of the LAA (white arrows), prominent coumadin ridge (yellow arrow) between the LAA and left upper pulmonary vein (red star) as seen by (B) 2D-TEE and (C) 3D-TEE en face view. D, E Transverse pericardial sinus (white star) as visualized by 2D-TEE