Left Atrioventricular Valve

Left Atrioventricular Valve

•  Left atrioventricular valve: This is another name for the mitral valve. It is called the “atrioventricular” valve because it connects an atrium (upper chamber) and a ventricle (lower chamber). It has 2 main leaflets Anterior leaflet and a posterior leaflet. The terminology of “anterior” and “posterior” is more of a convention in describing the valve, as the actual spatial positioning of the leaflets isn’t strictly anterior or posterior. (1,2)
• Left atrioventricular orifice: This is the opening that the left atrioventricular (mitral) valve covers. It’s the passageway through which blood flows from the left atrium to the left ventricle. (1,2)
• Anterior leaflet of the left atrioventricular valve: Although its position is not technically anterior, it’s referred to as the anterior leaflet due to its proximity to the aortic valve. It is the larger leaflet of the left atrioventricular valve, located between the atrioventricular and aortic orifices. For descriptive purposes in surgical practice, this leaflet is typically divided into three sections: A1, A2, and A3. (2)
• Posterior leaflet of the left atrioventricular valve:  It is the smaller leaflet of the left atrioventricular valve, which is located behind and to the left of the left atrioventricular orifice, is usually divided into three sections or “scallops” known as P1, P2, and P3. Although somewhat subjective, these divisions aid surgeons in describing the different regions of the leaflet.
• Commissural leaflets: These small leaflets are located at the angles where the anterior leaflet of the left atrioventricular valve intersects with the posterior leaflet. When the valve is closed, the commissural leaflets of the anterior and posterior leaflets meet, preventing the backward flow of blood from the left ventricle to the left atrium. (2)

Bibliography

1. Gray H, Lewis W. Angiology. In: Anatomy of the human body. 1918. p. 526–42
2. Faletra FF, Pandian NG, Ho SY. The Cardiac Valves. In: Anatomy of the Heart by Multislice Computed Tomography. Wiley-Blackwell; 2009. p. 55–80.

The structure and organization of anatomical terms used in this text follow the guidelines provided by FIPAT (2019) in their publication: FIPAT. (2019). Terminologia Anatomica (2nd ed.). FIPAT.library.dal.ca. Federative International Programme for Anatomical Terminology. Retrieved May 7, 2023, from https://fipat.library.dal.ca/TA2/