Eccentric hypertrophy of the left ventricle

Eccentric hypertrophy of the left ventricle in a mixed breed bitch. This animal exhibited level II endocardiosis in the parietal cusp of the mitral valve, a lesion which contributed to the development of eccentric hypertrophy. Note the irregular, mildly nodular appearance of the free rim of the cusp. Endocardiosis constitutes a progressive process of myxomatous degeneration, very common in adult and old dogs, in which the free border of the valvular cusps (usually the atrioventricular valves) which becomes progressively narrower and more irregular and may even, in certain cases, disappear almost completely.