What is another name for the mitral valve?

The Bicuspid Valve: Another Name for the Mitral Valve

The mitral valve is also known as the bicuspid valve, named for its characteristic two-leaflet structure consisting of anterior and posterior leaflets. 1, 2

Anatomical Structure of the Mitral (Bicuspid) Valve

• The mitral valve is a complex structure consisting of a saddle-shaped annulus, two asymmetric leaflets (anterior and posterior), chordae tendineae, papillary muscles, and left ventricular wall attachments 2
• The anterior mitral valve leaflet has a larger radial surface and is attached to about one-third of the annular circumference 1
• The posterior leaflet has a larger circumferential attachment (two-thirds of the annulus) and is quadrangular in shape 1
• Both leaflets are segmented into three individual scallops: A1, A2, and A3 (anterior) and P1, P2, P3 (posterior) from left to right 1
• The anterior mitral valve leaflet is in continuity with the left and noncoronary cusps of the aortic valve, forming what is known as the aortic-mitral curtain 1, 2

Functional Aspects of the Mitral (Bicuspid) Valve

• The mitral valve ensures unidirectional blood flow from the left atrium to the left ventricle 2
• During systole, the valve closes to prevent regurgitation of blood back into the left atrium 2
• During diastole, the valve opens to allow blood flow from the left atrium into the left ventricle 2
• The coaptation line between the leaflets has an upward concavity and can be checked for visible leaks while in the closed position 1

Clinical Significance

• Mitral valve prolapse (MVP) is the most common valvular disease in the general population, with an estimated prevalence of 2-3% 1
• MVP is defined as an abnormal systolic displacement of one or both leaflets into the left atrium below the mitral annulus 1
• Although generally considered benign, MVP can lead to complications such as mitral regurgitation, atrial fibrillation, heart failure, endocarditis, ventricular arrhythmias, and sudden cardiac death 1
• MVP has been reported to account for up to 11% of sudden cardiac death cases in young competitive athletes 1

Imaging Considerations

• Three-dimensional echocardiography provides superior visualization of the mitral valve structure compared to two-dimensional imaging 1
• The mitral valve should be displayed with the aortic valve placed superiorly at the 12 o'clock position, regardless of whether viewed from the left atrium or left ventricle 1
• The oval shape and saddle-shaped contour of the mitral annulus are best appreciated with 3D reconstruction techniques 1

Important Note

While the classical description of the mitral valve is bicuspid (with two leaflets), some anatomical studies have found variations in the number of cusps, ranging from monocuspid to hexacuspid 3. However, the standard terminology and most common anatomical presentation is that of a bicuspid valve 1, 2.