Congenital mitral valve anomalies are defects present at birth (congenital) that affect the heart's mitral valve. The mitral valve is located between the heart's upper left chamber (left atrium) and lower left chamber (left ventricle).
Various types of mitral valve anomalies exist, including:
- Thickened, stiffened, deformed or fused valve flaps (leaflets)
- Abnormalities with the cords that support the valve, such as short and thick cords, cords attaching to a heart muscle near the mitral valve, or missing cords
- Heart tissue or heart muscle problems near the mitral valve
These mitral valve anomalies can cause the mitral valve to not function normally. Some mitral valve anomalies may lead to mitral valve stenosis, in which the flaps become thick or stiff or fuse together. This causes a narrowed valve opening and reduced blood flow from the left atrium to the left ventricle.
Other mitral valve anomalies may lead to mitral valve regurgitation, in which the flaps don't close tightly, causing blood to leak backward into the left atrium. Mitral valve regurgitation may also be caused by the flaps bulging backward into the left atrium as your heart contracts (mitral valve prolapse). In some cases, people may have both mitral valve stenosis and mitral valve regurgitation.
Some people may have more than one opening in the area of the mitral valve, a condition called double-orifice mitral valve. In these people, one or both of the openings is often either narrowed (stenotic) or leaking (regurgitant).
People with mitral valve anomalies also often have additional congenital heart defects.