Mitral annular calcification is a degenerative disorder of the mitral annulus that occurs in 6% of elderly patients. Although it is part of the aging process it is a marker for other atherosclerotic diseases, and is commonly associated with aortic sclerosis which also occurs in similar patient populations. It has been suggested that MAC and aortic stenosis have a close link (Movahed)
Structurally at a histological level fibrillar degeneration of the collagen appears to be the precipitating event followed by dystrophic calcification. The calcification spares the portion of the annulus that is attached to the anterior leaflet of the mitral valve so that it is shaped like a backward “C” in the A-P projection and even in the lateral projection.
Functionally it often has no clinical bearing, but when severe it may cause mitral regurgitation, stenosis, or even extend into the conduction system where heart block may result.
It is best diagnosed by plain film but usually milder forms are not visualized. Echocardiography and CTscanning easily diagnose this condition.
Since it is a marker of cardiovascular disease treatment is directed at the associated conditions rather than at MAC.
MAC in an Elderly female
Note the incomplete ring of calcification. Calcification is absent in the anterior leaflet of the mitral valve
32744c01 heart mitral valve mitral annulus mitral annular calcification MAC aortic calcifications osteopenia bone thoracic spine kyphosis compression fracture CXR plain film of the chest IVC filter Davidoff MD
MAC Extending Down the Interventricular Septum
34130 heart mitral valve mitral annulus mitral annular calcification MAC progression down the interventricular septum conduction defects nerve involvement CTscan Davidoff MD