IN SEVERE INFECTIOUS DISEASES, un less there be signs of obstruction of a valve, it may be impossible to determine whether there be endocarditis or a myo carditis due to toxins, rendering the wall flabby and the mitral valve relatively incompetent.
Etiology. — Endocarditis is an infec tious disease, and almost always sec ondary to some other. It is most fre quently an expression of rheumatism. It may follow tonsillitis, pleurisy, chorea, measles, small-pox, and any acute infec tious disease, particularly scarlet fever. Pneumonia, influenza, erysipelas, gonor rhoea, pericarditis and meningitis may present this complication; as may also, in rare instances, typhoid fever, tuber culosis, and diphtheria. Osteomyelitis, puerperal fever (as well as other vaginal or uterine affections), empyema, bron chiectasis, external wounds, and any form of septicaemia may occasion endo carditis. Cancer, gout, diabetes, and Bright's disease may give rise to it.
Almost invariably some form of bac teria is found in the lesions; hut there does not seem to be any bacterium pecul iar to the disease. In both the simple and malignant forms the pyogenic micro organisms are those most often encount ered; namely, streptococci, staphylo cocci, pneumococci, and gonococci. Before birth the right side of the heart is almost exclusively affected; after birth, the left. Early adult life furnishes a majority of the cases; and, according to the latest statistics, men are somewhat more liable to the disease than women.
Eighty-four oases of infective endo carditis were met with at St. Bartholo mew's Hospital, from January, 1S90, to March, 1897. Fifty-one were males and thirty-three females; the average ages of males, 02.7 per cent. between 20 and 40 years: females, 51.5 per cent. between 10 and 30 years, and 33.3 per cent. be tween 15 and 25 years. In all but 10 cases either old cardiac disease or an inflammatory infective lesion accom panied the endoearditis. Of these 10, malignant disease occurred in 4: a pos sible pneumonia in 1; so that only 5 could be considered as uncomplicated, or as a primary infective endocarditis, not preceded by either cardiac lesions or in fective lesions in other parts of the body. There was pre-existing cardiac disease in 64.27 per cent.; 29.8 per cent. were ac
companied by recognized infective proc esses (not counting acute rheumatism or chorea as such). Bronchiectasis, em pyema, vaginal or uterine affections, and also influenza must be regarded as pyo sources of infection. An ante cedent pneumonia occurred in 14.28 per cent. of all the cases. When an endo carditis appears in the course of an in fective fever there may be homologous, heterologous, or mixed infection of the endocardium. The infective endoearditis in some cases may be merely a "ter minal infection," the miero-organisms invading the tissue just before death, without being actually responsible for the lethal ending. Kanthaek and Tickell (Edinburgh Med. Jour., July, '97).
Pneumonic endocarditis is not very infrequent. A malignant endocarditis arising in connection with pneumonia may be caused by (1) the pnennmeoccus and (2) the streptococcus and staphylo coccus. These different forms of the dis ease are differentiated by the course, t emperat ure - curve, and complications.
The course of a true pneumonic endo carditis is much shorter than that of a -treptococeic endoearditis. When malig nant endocarditis is due to the pueumo coccus, the fever is usually continuous. whereas in the other forms it is in termittent. Infarcts and metastatic ab scesses are very rare in pneumonic endo carditis, but are usually found in the endocarditis produced by the pyogenic microbes. Kerschensteiner (.Minch. med. Mach., Aug. 3, '97).
Thirty-six eases of endocarditis were studied from the bacteriological point of view by microscopical and culture methods. In thirty-four cases the result was positive, in two only it was nega tive. The histological examination in both these cases established the fact that they were not a true endocarditis, but an atrophic thrombosis. From an analysis of the cases it is concluded that (1) the diplococcus and the streptococcus are the most constant agents in eudocarditis; (2) that these are able to produce, whether alone or associated with other micro-organisms, the ulcerated as well as the VC1TUCOSC form; (3) that the diplo coccus more frequently causes aortic, and the streptococcus mitral, endoearditis. Ouse (Lo Sperim., anno lit, fast. I, '98).