INTRODUCTION
In the study of heart disease in the present, as in the past, one of the most important problems is that of the origin of chronic valvular disease in young people. Especially is this true now, since definite steps have been taken to organize activities directed toward the prevention of heart disease.In many cases it is, of course, easy to trace the onset of valvular deformity to some clear-cut attack of rheumatic fever or chorea. Often, it is more difficult to prove the occurrence of such infections in young people with chronic endocarditis, especially if the rheumatic fever or chorea have been very mild and the heart has not been carefully watched during and directly after the infection. Sometimes it is impossible to obtain any history of such illness in patients with chronic valvular disease in youth. Because rheumatic fever and chorea are the commonest known causes of