A system of practical medicine. By American authors. Vol. 3

by Unknown

The tendon of the mitral valve may show the effects of endocarditis by becoming soft and friable, and even rupturing, or the chordæ tendineæ may adhere to one another. When such adhesions occur either with agglutinations of the flaps to each other or to the heart-walls, stenosis or regurgitation may result.

In connection with these changes new vessels are developed in the substance of the mitral valve, or those that already exist become more apparent. In the semilunar valves new vessels are formed or neighboring capillaries send out prolongations into the parts destitute of vessels. This, according to Charcot, is one way in which arborescent vascularity occurs. These changes are most marked in those forms of exudative endocarditis which run an acute course.

In some instances the hyperplasia is so extensive as to interfere with nutrition, and may lead to fatty metamorphosis. A cavity is then formed filled with granular fat-cells, discrete fat-globules, and blood-pigment, whose endocardial covering ruptures, and the contents are carried into remote capillaries to cause capillary embolism and septicæmia. This has been called ulcerative endocarditis.

Ulcerative Endocarditis.

Ulcerative endocarditis occurs in those diseases where there is great vital depression. It is met with oftenest in pyæmia, puerperal fever, scarlatina, and diphtheria. It has been called septic, diphtheritic, and infectious endocarditis.¹

¹ Jaccoud, Klebs.

MORBID ANATOMY.—Ulcers may form in endocarditis in either one of three ways: 1st. The exudative process may be so rapid and extensive as to cut off the nutrition of the endocardium covering the apices of the papillary elevations, and ulcers result in non-septic inflammation. 2d. Degeneration of the neoplastic tissue, due either to deficient blood-supply or other causes of impaired nutrition, may so soften the villi or efflorescences that their apices will be swept away by the blood-current and ulcers thus be formed. Charcot especially insists that the ulceration of these elevations is the consequence of granular degeneration, and not of fatty metamorphosis, with which it is often confounded. 3d. The exudative process may be purulent in character, and form minute abscesses in the substance of the valves beneath the endocardium, which, rupturing, leave comparatively deep ulcers. Acute multiple abscesses in the aortic valves are of frequent occurrence in ulcerative endocarditis.

The margins of the ulcers are irregular, but well defined; the edges are swollen and thick, and their floor (the muscular substance of the heart or the fibrous layer of the valve) is infiltrated with pus.

Where there is extensive loss of substance perforation of the valve may occur. These perforations are sometimes closed or hidden by a fibrinous exudation.