Atrioventricular Valve: Structure and Function

Introduction

The heart is a complex organ that functions as a pump, maintaining circulation to supply oxygen and nutrients throughout the body. One of its crucial components is the atrioventricular (AV) valves, which ensure unidirectional blood flow between the atria and ventricles.

What Are Atrioventricular Valves?

The heart has four valves, and two of them belong to the atrioventricular category:

• Tricuspid valve – located between the right atrium and right ventricle
• Mitral (bicuspid) valve – located between the left atrium and left ventricle

These valves prevent backflow of blood when the ventricles contract, ensuring efficient circulation.

Anatomy and Function

1. Structure

• Cusps (Leaflets): Thin flap-like structures that open and close
• Chordae Tendineae: Fibrous cords that connect valve leaflets to papillary muscles
• Papillary Muscles: Prevent valve prolapse during contraction

2. How Do They Work?

• Diastole (Relaxation Phase): AV valves open, allowing blood to flow from the atria to the ventricles
• Systole (Contraction Phase): AV valves close to prevent backflow as the ventricles contract

Common Diseases of AV Valves

1. Mitral Valve Disease

• Mitral valve prolapse (MVP): Leaflets bulge back into the atrium
• Mitral stenosis: Narrowing of the valve, limiting blood flow
• Mitral regurgitation: Leakage of blood due to improper valve closure

2. Tricuspid Valve Disease

• Tricuspid regurgitation: Blood leaks backwards into the right atrium
• Tricuspid stenosis: Narrowing, leading to right atrial enlargement

Diagnosis and Treatment

1. Diagnosis

• Echocardiography: Ultrasound imaging of the heart
• Electrocardiogram (ECG): Assesses heart rhythm
• Cardiac MRI or CT: Provides detailed imaging

2. Treatment Options

• Medications: Diuretics, beta-blockers to manage symptoms
• Valve Repair or Replacement: Surgical intervention if needed (bioprosthetic or mechanical valve replacements)
• Transcatheter Valve Procedures: Less invasive options such as mitral or tricuspid clip procedures

Conclusion

Atrioventricular valves play a vital role in heart function by ensuring one-way blood flow and preventing leakage. Early diagnosis of valvular diseases can significantly improve quality of life through medical or surgical treatment.

Source recommendations

1. American College of Cardiology/American Heart Association Guidelines on Valvular Heart Disease

1. https://www.ahajournals.org/doi/10.1161/CIR.0000000000000923
2. https://www.acc.org/Latest-in-Cardiology/ten-points-to-remember/2020/12/16/21/58/2020-ACC-AHA-VHD-GL-Pt-1-GL-VHD
3. https://pubmed.ncbi.nlm.nih.gov/33332149/
4. https://www.acc.org/Latest-in-Cardiology/ten-points-to-remember/2024/03/13/18/13/2024-acc-aha-clinical-performance-valvular
5. https://pubmed.ncbi.nlm.nih.gov/33342586/

2. European Society of Cardiology Guidelines for the Management of Valvular Heart Disease

1. https://www.escardio.org/Guidelines/Clinical-Practice-Guidelines/Valvular-Heart-Disease-Guidelines
2. https://academic.oup.com/eurheartj/article/43/7/561/6358470
3. https://pubmed.ncbi.nlm.nih.gov/34453165/
4. https://www.ahajournals.org/doi/10.1161/CIR.0000000000000923
5. https://pubmed.ncbi.nlm.nih.gov/17259184/