Accessory mitral valve leaflet

The presence pf accessory mitral valve tissue in the left ventricular outfl ow tract (LVOT) is a rare cause of obstruction. Previous cases reported in the literature are associated either with other complex congenital abnormal ities, or with other forms of LVOT obstruction. This report presents the fi rst case of a duplication of the anterior leaflet of the mitral valve occur ring as an isolated congenital anomaly. It produced mild subaortic obstruct ion. The report emphasizes the importance of transthoracic two-dimensional echocardiography and Doppler assessment in the recognition of congenital ab normalities of the mitral valve and subvalvular apparatus as a differential diagnosis of subaortic stenosis.