Questions

Discussion of Questions

Double-orifice mitral valve is usually associated with other cardiac anomalies, so, it is supposed that DOMV is a congenital valve disease (Question A).

There are no specific clinical signs suggestive of DOMV. DOMV is usually an incidental finding in the diagnosis of the elderly patient and may be missed or undiagnosed in asymptomatic or even symptomatic patients. Most patients stay in normal sinus rhythm, but patients with significantly dysfunctional DOMV may present with heart failure, requiring initial medical therapy. The isolated cases of DOMV do not need therapy and can be followed up only by echocardiographic examinations. However, clinic manifestation and management depend not only on the severity of mitral valve dysfunction, but also on associated malformations, which cause pulmonary hypertension due to pulmonary hyperflow from intracardiac shunt (Question B).

Transthoracic echocardiogram, especially in parasternal short-axis views, is a reliable method and in most cases, sufficient to confirm a diagnosis of DOMV and to determine its type. 3D transthoracic echocardiogram is a diagnostic imaging method complementary to 2D transthoracic echocardiogram. Combining 2D and 3D transthoracic echocardiogram is extremely beneficial in the complete cardiac evaluation and management of DOMV (Question C).

In a severely stenotic DOMV, percutaneous balloon mitral valvuloplasty has been described, but the experience is limited. In most cases, the dividing bridge is composed of mitral and chordal tissue. Surgical transection of the dividing bridge is not advised in order to avoid iatrogenic mitral regurgitation. Therefore, a valve prosthesis is the most reliable surgical option (Question D).

Brief Consideration of the Case Reported

As the evaluation of dyspnea was mandatory for a possible surgery indication, the diagnosis was supplemented by ergospirometry and cardiac catheterization to better define the cause of dyspnea, clarified that the patient did not present pulmonary arteriolar hypertension and that pulmonary artery pressure was elevated by the presence of mitral valve insufficiency and ASD. Then the surgery was indicated. An atrial septostomy allows easy surgical access to the mitral valve apparatus that presented a duplicate mitral valve, with two separate mitral valve annuli, each with its own set of leaflets and subvalvular apparatus. It was implanted a 33M bovine pericardium prosthesis. Unfortunately, it was not possible to preserve the papillaries due to their irregular implantation. The immediate postoperative period was characterized by the difficulty of discontinuing respiratory care. The patient died after about 45 days, due to hospital pneumonia that evolved to septic shock^[1-7].

Learning Points