M-mode echocardiogram of mitral annular calcification

In this patient, mitral annular calcification (MAC) is seen in association with aortic valve stenosis. An M-mode tracing (panel A) of the aortic root (Ao) shows a thickened aortic valve (AV). Panel B shows a dense band of echoes from the mitral annulus, due to MAC, which are located posterior to the anterior leaflet of the mitral valve (ALMV); the posterior mitral valve leaflet is not seen because it is obscured by the artifacts that arise from the highly reflective, calcified annulus.