Abstract
During the past few decades, valvular heart disease has changed in type and character. The two principal reasons for the changes are a decline in the prevalence of rheumatic heart disease and the longer survival of the population in general and of patients with heart disease in particular. The two stenotic lesions of the cardiac valves on the left side have been particularly affected by the change. There has been a gradual decline in the incidence of mitral stenosis — a lesion almost entirely related to rheumatic fever. The types of aortic stenosis seen have shifted from rheumatic to nonrheumatic. . . .