[Pathological anatomy of post-infarction mitral valve insufficiency]

Failure of the bicuspid valve is one of the most frequent (20-25%) and grave complications of myocardial infarction. The causes of mitral failure occurring at different times following myocardial infarction are established. It is shown that the severity of coronary arteries lesions in postinfarction mitral failure is chiefly due to the occlusion of the two or three coronary arteries and to the segmental stenosis of more than 75% of the lumen of the main heart arteries. Postinfarction mitral failure caused by dysfunction of the papillary muscles may be provoked by acute infarction of the papillary muscles, rupture of the papillary muscle body, large-focal papillary muscle cardiosclerosis, by dilation of the left ventricular cavity and fibrous ring resulting in disturbance of space interrelationships between the tendinous filaments and valves.