[The calcified aortic valve. A morphologic study].

A histological study of 92 stenosed and calcified aortic valves is conducted to work out criteria with which to distinguish postrheumatic from degenerative calcification. The microscopic picture of a calcified aortic valve is fairly uniform and independent of a history of rheumatic fever. Thick walled and narrow muscular arteries with prominent elastic laminae are the only feature distinguishing calcified valves after rheumatic fever from valves showing degenerative calcification. This uniform morphology of the calcified aortic valves suggests a uniform process. The term "degenerative calcification" is used if this process occurs in an elderly patient, but a (histologically) nearly identical calcification is observed in younger people after rheumatic endocarditis or with congenitally bicuspid aortic valves. It is concluded that the basic process is the same (degenerative calcification) but that this degenerative process occurs earlier in patients with bicuspid valves or after rheumatic endocarditis.