ENDOCARDITIS AND CARDIAC VALVULAR DISEASES.
BY ALFRED L. LOOMIS, M.D.
Endocarditis.
DEFINITION.—Endocarditis is an inflammation of the endocardium, and may be either exudative, neoplastic, or ulcerative in character. While its different varieties are closely connected in their etiology, they are distinct in the extent, duration, character, and course of their pathological changes. They cannot be classified as acute and chronic in the ordinary acceptation of these terms, for they often so merge into each other as to render it difficult, if not impossible, to determine when they cease to be acute and become chronic; and some cases are at no time acute. It has been claimed that an acute endocarditis becomes chronic when its course is prolonged, but the advanced changes are only a stage of the acute process.
So-called acute endocarditis is accompanied by a fibro-cellular exudation into the substance of, and underneath, the endocardium, causing elevations of its surface. The better term for this variety is exudative endocarditis, it being borne in mind that the exudation does not take place upon the free surface of the membrane, but into its substance and underneath it. This form of endocarditis may be entirely recovered from, or it may lead to interstitial changes in the endocardial and myocardial tissue which will correspond to the changes usually described as those of chronic endocarditis.
Interstitial endocarditis is a better term for these changes. The disease may be the sequela of exudative endocarditis, or may be interstitial from its commencement, for the valvular changes of interstitial endocarditis are often found in those who never have had either acute articular rheumatism or exudative endocarditis, but have been the subjects of chronic rheumatism or gout.
Acute exudative endocarditis may, in certain cases, be stamped with an ulcerative process, the result of septic infection, giving rise to those pathological changes which have been described as acute ulcerative endocarditis.