We describe a case of a 63-year-old patient admitted to our hospital because of cardiogenic shock. Past medical records showed anterior myocardial necrosis, myocardial surgery revascularization with apical aneurysmectomy and, 3 weeks before, another coronary artery bypass operation due to malfunction of the previous grafts and mitral annuloplasty with placement of a Carpentier-Edwards Physio no. 28 prosthetic ring. Transthoracic echocardiography revealed, in the middle of the mitral orifice, the presence of an echogenic structure with hypermobility and severe peri-ring mitral regurgitation due to dehiscence of the posterior side of the prosthetic ring. The diagnosis was finally confirmed by surgery and then mitral valve replacement was performed.