Pathology

If a chronic endocarditis has followed an acute condition, some slight permanent papillomas or warty growths may he left from the healed granulating or ulcerated surfaces. Sometimes these little elevations on the valves become inflamed and then adhere together, or adhere to the wall of the heart, and thus incapacitate a valve. Sometimes these excrescences undergo partial fatty degeneration, or may take on calcareous changes and thus stiffen a valve.

If the chronic inflammation is not superimposed on an acute endocarditis there may be no cell infiltration and therefore no softening, but there is a tendency to develop a fibrillated structure, and a fibroid thickening of the endocardium occurs, especially around the valves. This induration causes contraction and narrowing of the orifices with shortening and thickening of the chordae tendineae, and the valves imperfectly open, or no longer close. Fatty degeneration may occur in the papillary growths with necrotic changes, and this may lead to the formation of atheromatous ulcers which may later become covered with lime deposits, and then a hard calcareous ring may form. Fibrin readily deposits on this calcareous substance and may form a permanent capping, or may slowly disintegrate and allow fragments to fly off into the blood stream and cause more or less serious embolic obstruction. If this chronic endocarditis develops with a general arteriosclerosis, the wine inflammation soon occurs in the aorta, and, following the endarteritis in the aorta, atheromatous deposits may also occur there. Chronic endocarditis of the walls of the heart, not in immediate continuity with endocarditis of the valves, is perhaps not liable to occur, except with myocarditis.