RESUMEN
Results of long-term prospective follow-up of patients with early stages of mitral and aortic valvulitis and primary chronic septic endocarditic are presented. Clinical diagnostics of the diseases is described and the key role is assigned to pathognomic (absolute) clinical symptoms. The tendency to progressive fibrosis of endocardial structures with subsequent gradual development of valve dysfunction and stenosis (especially for the mitral valve) is revealed. It is shown that early treatment increases the effective valve area and promotes reversion of mitral stenosis. The possibility of early diagnostics of primary chronic septic endocarditis in combination with adequate etiopathogenetic therapy provide the basis for prevention of acquired valvular disease.