The tensor apparatus in double-orifice mitral valve: interpretation of echocardiographic findings.

We describe a rare case of double-orifice mitral valve discovered with echocardiography. The tensor apparatus composed of four papillary muscles and anomalous attachment of chordae tendineae represents the main findings. Two supernumerary muscles in combination with the altered chordal insertion on the central portion of the anterior mitral leaflet are responsible for the V-shaped ("seagull wing") and spectacle-like features of the mitral valve in the short-axis view. These altogether allow precise identification of this congenital malformation.