Role of echocardiography in the diagnosis and surgical management of accessory mitral valve tissue causing left ventricular outflow tract obstruction.

We report an unusual case of left ventricular outflow tract obstruction caused by accessory mitral valve tissue. This case illustrates the importance of transthoracic echocardiography in preoperative evaluation and the usefulness of transesophageal echocardiography for intraoperative assessment. If the accessory mitral valve has no functional significance it may be surgically excised, thereby relieving the outflow tract obstruction.