Figure 2. Morphologic Variation in Left Atrial Appendage Ostia Adapted with permission from Cabrera; Heart 2014 Panel A. The ostium of the left atrial appendage with a “chicken wing” morphology is shown. Notice the slightly elliptical morphology of the os. In addition, the proximity to the mitral valve (MV) is seen. Also of note are the crevices/pits surrounding the ostium. Panel B. Amplatzer Cardiac Plug in situ 10 mm from the ostium to occlude the appendage. Notice that after appendage occlusion, there the divots are “unprotected”. Also note the proximity of the device to the circumflex artery (LCx) and mitral valve (MV). Panels C-D: Variant ostial morphology; these are classified as C) “round” ostial variant, D) “elliptical: variant”, E) triangular, F) “water-drop like”, G) “foot-like”. MV; mitral valve.