From January/1982 to March/1984, 170 high profile bovine pericardium bioprostheses were implanted in the INCOR (Instituto do Coração), Hospital das Clínicas, Faculdade de Medicina da Universidade de São Paulo (FMUSP). Hospital mortality amongst these patients was 7.1%. Anatomopathological studies identified five cases in which obstruction of the left ventricle outlet occurred after substitution of the mitral valve. Based on this experience, the indication of a hemodynamic study on the first postoperative day of a patient with an unexplained low cardiac output made it possible to identify obstruction of the left ventricle valve outlet in such patients, with resubstitution of the valve and a satisfactory evolution of the case. In this report we relate the six cases in detail and discuss the causes of the obstruction of the outlet in mitral valve substitutions.
left ventricle outlet; heart valves, mitral; heart valves, mitral