Summary about Disease
Rheumatic mitral stenosis (RMS) is a heart valve disorder where the mitral valve, located between the left atrium and left ventricle, narrows. This narrowing obstructs blood flow from the left atrium to the left ventricle, leading to a backup of blood in the left atrium and lungs. It is almost always caused by rheumatic fever, a complication of untreated strep throat or scarlet fever.
Symptoms
Symptoms of RMS can vary from mild to severe, depending on the degree of valve narrowing. Common symptoms include:
Shortness of breath, especially with exertion or when lying flat (orthopnea)
Fatigue
Palpitations (feeling a rapid or irregular heartbeat)
Cough, sometimes with blood (hemoptysis)
Swelling of the ankles and feet (edema)
Chest pain or discomfort
Atrial fibrillation (irregular heartbeat)
Dizziness or fainting
Causes
RMS is almost exclusively caused by rheumatic fever, a systemic inflammatory disease that can develop as a complication of untreated or inadequately treated strep throat or scarlet fever caused by Streptococcus pyogenes bacteria. Rheumatic fever can damage the heart valves, including the mitral valve, leading to scarring and narrowing over time.
Medicine Used
Medical management aims to control symptoms and prevent complications. Medications may include:
Diuretics: To reduce fluid overload and alleviate shortness of breath and edema (e.g., furosemide).
Beta-blockers or Calcium Channel Blockers: To slow the heart rate and control palpitations, particularly in atrial fibrillation (e.g., metoprolol, diltiazem).
Anticoagulants: To prevent blood clots, especially in patients with atrial fibrillation (e.g., warfarin, direct oral anticoagulants).
Antibiotics: To prevent recurrent rheumatic fever attacks (e.g., penicillin). Note: Medications are not a cure for the valve stenosis itself but manage the symptoms. Severe cases require intervention such as balloon valvuloplasty or valve surgery (repair or replacement).
Is Communicable
RMS itself is not communicable. It is a consequence of rheumatic fever, which, in turn, is a complication of strep throat or scarlet fever. Strep throat and scarlet fever *are* communicable, spread through respiratory droplets.
Precautions
Prompt Treatment of Strep Throat: The most important precaution is to seek prompt and complete treatment for strep throat with antibiotics to prevent rheumatic fever.
Prophylactic Antibiotics: Individuals with a history of rheumatic fever often need long-term prophylactic antibiotics to prevent recurrent strep infections and further heart damage.
Regular Medical Follow-up: Regular check-ups with a cardiologist are crucial to monitor the progression of the disease and manage symptoms.
Healthy Lifestyle: Maintaining a healthy lifestyle, including a balanced diet, regular exercise (as tolerated), and avoiding smoking, can help improve overall cardiovascular health.
Dental Hygiene: Good dental hygiene is important to prevent bacterial endocarditis, an infection of the heart valves.
How long does an outbreak last?
RMS is not an outbreak-related illness. Rather, it develops slowly over time as a result of damage from rheumatic fever. The initial episode of rheumatic fever typically lasts several weeks to months. However, the damage to the mitral valve can take years to manifest as significant mitral stenosis.
How is it diagnosed?
Diagnosis typically involves:
Medical History and Physical Examination: Listening for a characteristic heart murmur.
Echocardiogram: An ultrasound of the heart is the primary diagnostic tool. It shows the narrowed mitral valve, the degree of stenosis, and the size of the left atrium.
Electrocardiogram (ECG): Can detect atrial fibrillation or other arrhythmias.
Chest X-ray: May show an enlarged left atrium and pulmonary congestion.
Cardiac Catheterization: Occasionally needed to assess the severity of stenosis and pulmonary artery pressure.
Timeline of Symptoms
The timeline of symptoms can vary:
Initial Strep Throat/Scarlet Fever: Few days of sore throat, fever, rash (scarlet fever).
Rheumatic Fever (if untreated): Develops 1-5 weeks after strep infection. Can manifest with fever, joint pain, carditis (inflammation of the heart), skin rash, and involuntary movements (Sydenham's chorea).
Latent Period: Years or even decades can pass between the rheumatic fever episode and the development of significant mitral stenosis symptoms.
Progressive Symptoms: Shortness of breath, fatigue, and other symptoms gradually worsen as the valve narrows over time.
Important Considerations
Pregnancy: RMS can pose significant risks during pregnancy due to increased blood volume and cardiac output. Careful monitoring and management are essential.
Infective Endocarditis Prophylaxis: Patients with RMS are at increased risk of infective endocarditis and may require antibiotic prophylaxis before certain dental or surgical procedures.
Severity of Stenosis: The severity of stenosis determines the appropriate management strategy. Mild stenosis may only require monitoring, while severe stenosis typically requires intervention.
Atrial Fibrillation Management: Atrial fibrillation is a common complication and requires specific management with rate control, rhythm control, and anticoagulation.
Lifelong Monitoring: Even after intervention (balloon valvuloplasty or surgery), lifelong monitoring is necessary to detect and manage potential complications.