ACQUIRED AFFECTIONS OF THE ENDOCARDIUM (a) ENDOCARDITIS IN GENERAL Etiology and Occurrence.—In its etiology, occurrence, symp tomatolow and course, endocarditis in childhood differs considerably from endocarditis in adults. It is found as a congenital condition, with or without arrested cardiac development, and attacks especially the valvular apparatus of the right side of the heart, and the arterial val vular apparatus rather more than the venous. On the contrary, in extra-uterine life the atrioventricular valvular apparatus on the left side of the heart is chiefly attacked. Foetal as well as extra-uterine endo carditis of childhood usually seeks for its seat the valves which are exposed to the greatest tension. Foetal endocarditis has already been treated among the congenital heart lesions. Here Hochsinger briefly considers as endocarditis that acquired after birth.
As regards the frequency of endocarditis in general, the figures covering'a period of ten years, from the Children's Dispensary in Flor ence, are of value. It was found in Gi out of 4948 children, affecting the mitral valve in 54 (in six pericarditis and aortic affections were pres ent at the same time), while in one case there was pure aortic endocarditis.
Rheumatism plays the principal part in the production of endocar ditis in childhood. From Weill's large statistics, GO per cent. of the endocarditis of children was found to be rheumatic in nature. Church found the endocardium affected by rheumatism in 80 per cent. of chil dren with endocarditis. With this understood, stress should be laid on the fact that, in comparison with the slight frequ'ency of rheumatism among children, endocarditis in childhood cannot be called a rare dis ease. According to Hochsinger's investigations, acquired endocarditis is very rare before the fifth year; then it rapidly increases in frequency and is most, frequent between the tenth and fourteenth years. Both sexes are equally affected.
lindocarditis in children is only rarely idiopathic, being as a rule a secondary clisease. Among Weill's 25S children with endoearditis,
To the causes given in Weill's statistics smallpox, chicken-pox, relapsing fever, pyamiic and septic processes and erysipelas should be added. Syphilitic endocarclitis also occurs in children.
With regard to the rheumatic etiology, cases published as occurring in infancy in association \vith endocarditis must remain in doubt. Joints may be swollen in infancy with endoearditis, but they are always de pendent upon gonorrhcea, syphilis or pyTmia, not upon rheumatism. The youngest child suffering with rheumatic polyarthritis whom Hoch singer has observed was two and one half years of age. In the rheumatic etiology of endocarditis of children, besides, nodular rheumatism, chronic arthritis of children and acute and chronic muscular rheumatism (torti col/is) are to bc mentioned. In children more than in adults is it true that the endocarcliurn acts like a synovial membrane. Not rarely endo carditis first appears after the second or third attack of rheumatism. Church found endocarditis with the first attack of rheumatism in 57 per cent. of children; with the second attack, in 75 per cent. West found endocarditis in 62 per cent., Cheacile in SO per cent., Weill in 60 per cent., Fuller, in 54 per cent., Cassel in 62 per cent. and Ilochsinger in 57 per cent. of the cases of children with rheumatism.
Coucetti has recently taken quite a different stand, denying the intimate relation between rheumatism and the child's heart, as he found slight endocarditis only once among eight cases of acute rheumatism. On the whole lie found disease of the left side of the heart in connection with rheumatism in 27.65 per cent.; 19.15 per cent. were due to acute infections and in 53.19 per cent. none of the etiological conditions men tioned could be found.
Coneetti supposes a congenital cardiac dystrophy as the predis posing cause of the cases not founded upon infectious diseases.