Unexpected Echocardiographic Findings: Accessory Mitral Valve Tissue in Adults

Background: Accessory mitral valve tissue (AMVT) is a rare congenital cardiac anomaly, which is associated with other congenital heart diseases. It is diagnosed in neonates or childhood and rarely in adulthood. Nevertheless, AMVT is an incidental finding or described as isolated. Echocardiography, especially three-dimensional(3D) echocardiography is considered as an optimal imaging technique for AMVT diagnosis.Case presentation: We herein presented the two asymptomatic adult cases with AMVT, who presented with varying degrees of symptomatic left ventricular outflow tract (LVOT) obstruction. One presented with mild LVOT obstruction and no surgery was required, and another one with significant LVOT obstruction was recommended for surgical excision.Conclusions: We emphasized the usefulness of echocardiography in the morphology detection of AMVT, and the importance of operation guidance and follow-up.