Valvular atrial fibrillation (valvular AF) is a specific type of atrial fibrillation, a common cardiac arrhythmia where the upper chambers of the heart (the atria) beat irregularly and out of coordination with the lower chambers (the ventricles). The “valvular” aspect refers to the presence of structural heart problems related to the heart valves, which can complicate the condition and its management.
Causes of Valvular Atrial Fibrillation
Valvular AF usually arises in people with heart valve conditions, especially those involving the mitral valve. Common causes include:
- Rheumatic Heart Disease: Often linked to past untreated strep infections, this condition can lead to thickening and scarring of the mitral valve, contributing to atrial fibrillation.
- Mitral Valve Stenosis: A narrowing of the mitral valve, often due to rheumatic heart disease, increases pressure in the left atrium, leading to enlargement and atrial fibrillation.
- Mitral Valve Regurgitation: When the mitral valve doesn’t close properly, it can cause blood to flow backward into the atrium, stretching the atrium and potentially triggering atrial fibrillation.
- Artificial Valve Implants: Patients with mechanical or bioprosthetic heart valve replacements may develop AF due to the altered structure and function of the heart.
Symptoms of Valvular Atrial Fibrillation
The symptoms of valvular AF are similar to those of non-valvular atrial fibrillation but may be more severe due to the underlying valve disease. Common symptoms include:
- Palpitations (irregular or rapid heartbeat)
- Shortness of breath, especially with exertion
- Fatigue
- Dizziness or lightheadedness
- Chest discomfort
Risks and Complications
Valvular atrial fibrillation increases the risk of complications like stroke, heart failure, and other heart-related issues. Due to the irregular heart rhythm, blood can pool in the atria, leading to the formation of blood clots. If a clot dislodges, it can travel to the brain, causing a stroke. Patients with valvular AF are often at higher risk for these complications due to the combined effect of atrial fibrillation and valve disease.
Diagnosis
Diagnosing valvular AF involves a combination of clinical evaluation, imaging, and electrocardiographic studies:
- Electrocardiogram (ECG): Identifies the irregular rhythm characteristic of AF.
- Echocardiogram: Provides detailed imaging of the heart’s structure, allowing physicians to assess valve function and detect any enlargement of the atria.
- Holter Monitoring: Continuous heart monitoring over a period to detect intermittent episodes of atrial fibrillation.
Treatment
Managing valvular atrial fibrillation requires addressing both the arrhythmia and the underlying valve problem:
- Anticoagulation Therapy: Patients with valvular AF are often prescribed blood thinners (like warfarin) to reduce the risk of stroke. In valvular AF, warfarin is the preferred choice over newer anticoagulants (NOACs).
- Rate or Rhythm Control: Medications like beta-blockers, calcium channel blockers, or antiarrhythmic drugs are used to either control the heart rate or restore normal rhythm.
- Valve Repair or Replacement: For those with significant valve disease, surgical or transcatheter interventions may be necessary to repair or replace the affected valve.
- Catheter Ablation: In some cases, a minimally invasive procedure to destroy the areas of the heart tissue causing the irregular rhythm may be recommended.
