Cardiac Valves: Structure, Function, and Diseases

Introduction

The human heart contains four valves that ensure blood flows in the correct direction. These valves act like gates that open and close with each heartbeat, preventing backflow.

Structure and Function of the Heart Valves

There are four heart valves:

1. Aortic Valve – Controls blood flow from the left ventricle to the aorta, supplying oxygen-rich blood to the body.
2. Mitral Valve – Separates the left atrium and left ventricle, allowing blood to flow from the lungs to the heart.
3. Pulmonary Valve – Regulates blood flow from the right ventricle to the lungs for oxygenation.
4. Tricuspid Valve – Separates the right atrium from the right ventricle and ensures proper blood flow into the heart.

Common Heart Valve Disorders

Heart valve diseases occur when a valve doesn’t function properly. Common conditions include:

• Aortic Stenosis: Narrowing of the aortic valve, making it difficult for blood to leave the heart.
• Mitral Regurgitation: The mitral valve doesn’t close properly, allowing blood to leak backward.
• Mitral Valve Prolapse: The valve's leaflets bulge back into the atrium, sometimes causing leakage.
• Endocarditis: Infection of the heart valves, which can lead to serious complications.

Causes and Risk Factors

Heart valve diseases can be caused by:

• Age-related valve degeneration
• Rheumatic fever (previous streptococcal infection)
• Congenital heart disease (present at birth)
• Infective endocarditis (bacterial infection of the valves)

Symptoms

Symptoms of valve disease include:

• Shortness of breath
• Fatigue
• Chest pain
• Dizziness or fainting
• Swelling in the legs or ankles

Diagnosis

Doctors diagnose valve diseases using:

• Echocardiography – An ultrasound of the heart to assess valve function.
• Electrocardiogram (ECG) – Measures the heart's electrical activity.
• Cardiac MRI – Provides detailed heart images.
• Cardiac catheterization – Measures pressure and blood flow in the heart.

Treatment Options

The treatment depends on the severity:

• Medications for symptom control (diuretics, beta-blockers, anticoagulants).
• Valve repair or replacement:
  • Surgical valve replacement (mechanical or biological prosthetics).
  • Transcatheter Aortic Valve Replacement (TAVR) – A minimally invasive procedure.

Prevention and Lifestyle Changes

• Maintain a healthy diet (low in salt and unhealthy fats).
• Engage in regular physical activity.
• Control risk factors like hypertension and diabetes.
• Take antibiotics before dental procedures if at risk for infective endocarditis.

Conclusion

Heart valves are essential for proper cardiovascular function. Early detection and treatment of valve disorders can improve quality of life and prevent complications. If you experience symptoms, consult your doctor for evaluation.

Source recommendations

1. 2020 American College of Cardiology/American Heart Association Guidelines for the Management of Valvular Heart Disease

1. https://www.ahajournals.org/doi/10.1161/CIR.0000000000000923
2. https://pubmed.ncbi.nlm.nih.gov/33332149/
3. 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
4. https://pubmed.ncbi.nlm.nih.gov/33342586/
5. https://professional.heart.org/en/science-news/2020-acc-aha-guideline-for-the-management-of-patients-with-valvular-heart-disease

2. 2021 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/35636831/