General
The Mitral Valve is the only bicuspid (Two leaflet) valve in the heart. The name itself originates back to Leonardo Da Vinci who named the valve after the “Bishop’s Mitre”; the classic two-peaked hat the Catholic Bishops would wear. The anterior leaflet is the larger of the two, and is continuous with the Aortic Valve. As with the Aortic Valve the tissue composition of the leaflets is non-muscular, however, strings to ventricular muscles connect to the Mitral valve. Thus, ventricular contraction directly contributes to the closure of the valve. Pressure differences and blood flow will contribute additionally to the valve’s opening and closure.

Diseases that weaken or damage the valve causes the valve to leak (regurgitate) from insufficient closure.  This regurgitation causes blood to flow back into the left atrium. Consequently, blood supply to the rest of the body is decreased. Normally the heart will pump harder to compensate for this, resulting in enlargement of the heart which again will further contribute to increased regurgitant flow; a vicious circle is created.