Mitral annular calcification

The anatomic specimen (panel A) is sectioned along the long axis of the heart; the infiltrative calcific process just beneath the posterior mitral valve (pML) is called mitral annular calcification (MAC) or subannular calcification. The latter term is probably preferable because the process actually infiltrates the posterior wall (PW) myocardium. In this case, the infiltration extends nearly halfway through the basal myocardium and nearly one-third of the way to the papillary muscle (PM). The long axis echocardiogram from a patient with MAC (panel B) shows that the image faithfully represents the pathologic process; MAC extends at least one-third of the way from the mitral annulus to the PM base.