RESUMO
The authors report a case of a patient of 72 years of age in whom the sudden onset of severe left ventricular failure led to the discovery of massive mitral incompetence. The diagnosis of rupture of the posterior papillary muscle of the mitral valve, which was suggested on clinical and echocardiographic grounds, was confirmed at operation. This was carried out after 72 hours of assisted circulation by counter-pressure, and consisted of a replacement by a prosthetic valve. The authors emphasise, in the light of this case, the importance of echocardiography by ultrasound in the early diagnosis of this type of acute mitral incompetence, clarify the signs, and emphasise the part played by assisted circulation with an intra-aortic balloon in the treatment of this condition.