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Updated: Sep 13, 2026
Biaxial Mechanical Characterizations of Atrioventricular Heart Valves
Published on: April 9, 2019
Is the morphologically right atrioventricular valve tricuspid?
1Department of Paediatrics, National Heart & Lung Institute, London, United Kingdom.
Insights
The right atrioventricular valve typically has three leaflets, despite variations in structure. Its unique closure pattern, forming three lines of apposition, distinguishes it from the mitral valve.
Area of Science:
- Anatomy
- Cardiology
- Surgical Anatomy
Background:
- The anatomical classification of the right atrioventricular valve components is complex.
- Clarification of its structure is needed for accurate understanding.
Purpose of the Study:
- To analyze the structure of the right atrioventricular valve.
- To define its component parts and anatomical configuration.
Main Methods:
- Examination of 50 human hearts.
- Cross-sectional echocardiography to visualize the valve in a closed position.
- Three-dimensional reconstruction of the valve structure.
Main Results:
- 62% of specimens exhibited three leaflets.
- 30% had two leaflets, and 8% had four leaflets.
- Echocardiograms consistently showed three lines of closure.
Conclusions:
- The right atrioventricular valve should be considered tricuspid.
- Eccentric papillary muscle placement results in three lines of leaflet apposition.
- This distinct closure pattern differentiates it from the mitral valve.
Background And Aim Of Study:
Classification of the components of the right atrioventricular valve by its anatomical configuration is problematic and needs clarification.
Methods:
Fifty hearts were studied so as to analyze carefully the structure of the right atrioventricular valve and to define its component parts. Cross-sectional echocardiograms were reviewed to demonstrate the valve in closed position, and reconstructed in three-dimensional fashion.
Results:
The majority of specimens (62%) had three readily identifiable leaflets, but some (30%) could be described as having two leaflets while (8%) had four leaflets. The cross-sectional echocardiograms reviewed showed three definite lines of closure in all cases.
Conclusions:
The eccentric placement of the anterior papillary muscle causes the leaflets to close with three lines of apposition, and this makes the valve readily distinguishable from its mitral partner. When present, extra "scallops" in the structure of the right atrioventricular valve merely allow better coaption of the leaflets. So, although the term "cusp" is less than adequate as the descriptive basis for the structure of an atrioventricular valve, the right atrioventricular valve should still be considered to be tricuspid.
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