Mitral supravalvular ring: a case report

Abstract

Supravalvular mitral stenosis is a rare condition characterized by an abnormal ridge, with one or two orifices, covering and obstructing the mitral valve. Preoperative diagnosis is difficult with transtoracic echo (TTE), angiography and magnetic resonance imaging (MRI). In this case, a 36-year-old male, was admitted to our Heart department: He experienced progressive dyspnea on effort and at rest. Diagnosis was made by transesophageal echocardiography which showed, on apical 4-chamber section, an annular structure attached since a membrane to the atrial wall anterior mitral valve leaflet and just proximal to the posterior mitral leaflet. Pre-operative identification of the supravalvular mitral ring is the target for obtaining good surgical results. Cineangiography and MRI both failed in reaching this objective, whereas, transesophageal echocardiography is the best method to identify this congenital heart disease. Using TEE the identification is not only possible but also easier.

Figure 1

The transthoracic echocardiogram (TTE) showed left ventricular enlargment, atrial dilatation, moderate/severe mitral regurgitation and moderate aortic regurgitation mitral valve masses were suspected.

Figure 2

TEE showed, on apical 4-chamber section, an anular structure attached like a membrane to the atrial wall anterior mitral valve leaflet and just proximal to the posterior mitral leaflet.

Figure 3

MRI cine turbo-flash images acquired on a 1.5 T scanner(Magnetom Vision-Siemens) in four-chamber (3A) and transverse plane, short-axis view (Fig. 4). These images didn't show congenital heart disease.

Figure 4

MRI cine turbo-flash images acquired on a 1.5 T scanner(Magnetom Vision-Siemens) in four-chamber (3A) and transverse plane, short-axis view. These images did n't show congenital heart disease.