Accessory Mitral Valve Tissue in Both Obstructive and Nonobstructive Hypertrophic Cardiomyopathy Cases.

Accessory mitral valve tissue (AMVT) is a rare congenital cardiac anomaly often associated with other congenital heart defects. Typically diagnosed in childhood, its presence in adulthood is exceptionally rare, especially in patients with hypertrophic cardiomyopathy (HCM). The coexistence of these two conditions can complicate the diagnosis, particularly in patients with left ventricular outflow tract (LVOT) gradient formation. This case series highlights the importance of multimodal imaging in accurately identifying AMVT, differentiating it from other conditions, and determining the various morphologies of AMVT.