Bicuspid aortic valve

The M-mode echocardiogram (panel B) is obtained from the parasternal long axis view of the two dimensional echocardiogram (panel A); the dotted line indicates the plane of imaging. Although not obvious in the long axis view, the M-mode echocardiogram shows a typical feature of a bicuspid aortic valve (ie, eccentricity of closure; arrow). Normally, the image of the closed valve is centered in the middle of the aortic root. In this example, the closure occurs anterior of the center and the anterior leaflet (right cusp) is thickened. Such eccentricity is typical of congenitally abnormal valves with fused commisures, forming a bicuspid valve.