From January 1964 until February 1985, we performed 8,370 prosthetic valve procedures; this represents 54.32% of our total surgical load. Approximately 93% of the replacements were for rheumatic valve disease; the rest were for ischemic, myxomatous, degenerative, congenital, and traumatic heart disease. All cases were between New York Heart Association (NYHA) Classes II and IV; almost all patients had heart catheterizations before surgery. During the last 6 years, all patients had echocardiograms before undergoing heart catheterization.