Two Cases of Double-Orifice Mitral Valve Detected by Echocardiography

ABSTRACT

Double-orifice mitral valve is a rare congenital anomaly. Most cases of double-orifice mitral valve are hemodynamically normal and remain symptomless, so that it is usually discovered incidentally in autopsy or during surgical correction of a cardiovascular abnormality. Recently, however, it is increasingly recognized as such, since the echocardiography has gained wide acceptance as a non-invasive diagnostic tool by the M-mode, two-dimensional and color Doppler echocardiogram. Two separate mitral valve apparatuses can be used on the M-mode echocardiogram. In the two-dimensional echocardiography, the parasternal and subcostal short-axis views can show two separate glass-like orifices in the left ventricle, and the parasternal long-axis view as well as the apical four-chamber view can show the anomaly. And the color Doppler echocardiogram can visualize two mosaic-pattern flows between the left atrium and ventricle. We present herewith two cases of double-orifice mitral valve, as diagnosed by means of echocardiography. The first case was an isolated one with mitral stenosis, showing two parachute mitral valves. The second was associated with perimembranous ventricular septal defect, and showed the accessory mitral valve directly attached to the ventricular septum, with the chordae crossing the ventricular outflow tract.