Rheumatic Heart Disease (RHD)

• Rheumatic heart disease (RHD) is a chronic heart condition resulting from rheumatic fever, which is triggered by inadequately treated streptococcal infections, such as strep throat or scarlet fever.
• RHD is a serious but preventable condition.

Causes

• RHD begins with a streptococcal infection, typically of the throat.
• If the strep infection is not properly treated, it can lead to acute rheumatic fever (ARF).
• ARF is an inflammatory response that can affect the heart, joints, brain, and skin.
• RHD develops when the inflammation from ARF causes permanent damage to the heart valves.
• The mitral valve is the most commonly affected, followed by the aortic, tricuspid, and pulmonary valves.
• Damage to the heart valves can result in stenosis (narrowing), regurgitation (leakage), or both.
• The exact mechanism by which strep infections trigger ARF is not fully understood, but it is believed to involve an autoimmune response.
• The body's immune system mistakenly attacks the heart tissue after being exposed to streptococcal bacteria.

Symptoms

• Symptoms may not appear until years after the initial episode of rheumatic fever.
• The symptoms of RHD vary depending on the severity of valve damage and which valves are affected.
• Symptoms can include:
  • Shortness of breath, especially during physical activity or when lying down.
  • Chest pain or discomfort.
  • Fatigue and weakness.
  • Palpitations (irregular heartbeats).
  • Swelling in the ankles or feet (edema).
  • Dizziness or fainting.
  • Heart murmur (an abnormal sound heard during a heartbeat).

Diagnosis

• Diagnosis typically involves a combination of:
  • Medical history and physical examination: The doctor will inquire about any history of strep infections or rheumatic fever, and listen to the heart for murmurs or other abnormal sounds.
  • Echocardiogram: This is the primary diagnostic tool, using ultrasound waves to create detailed images of the heart, allowing doctors to assess the structure and function of the heart valves and detect any abnormalities.
  • Electrocardiogram (ECG): This test records the electrical activity of the heart and can help identify arrhythmias or other heart problems.
  • Chest X-ray: This imaging technique can reveal enlargement of the heart or fluid in the lungs, both of which may be associated with RHD.
  • Blood tests: Blood tests may be performed to look for evidence of a recent strep infection or inflammation in the body.

Prevention

• The primary strategy for preventing RHD is the prompt and complete treatment of streptococcal throat infections with antibiotics, usually penicillin or amoxicillin.
• Secondary prophylaxis involves long-term antibiotic treatment to prevent recurrent strep infections and subsequent episodes of ARF.
• This is particularly important for individuals who have already had ARF or RHD.
• Improved hygiene and sanitation can help reduce the spread of streptococcal infections.
• Public health initiatives aimed at raising awareness about RHD and promoting early diagnosis and treatment of strep throat are also crucial.
• Development of a vaccine against Streptococcus pyogenes is an area of ongoing research.

Treatment

• There is no cure for RHD, so treatment focuses on managing symptoms, preventing complications, and slowing the progression of the disease.
• Medications:
  • Antibiotics: Long-term antibiotics are prescribed to prevent recurrent strep infections and further heart damage.
  • Diuretics: These medications help reduce fluid buildup in the body, relieving symptoms such as swelling and shortness of breath.
  • ACE inhibitors or ARBs: These drugs help lower blood pressure and reduce the workload on the heart.
  • Beta-blockers: These medications slow the heart rate and lower blood pressure, reducing chest pain and palpitations.
  • Anti-arrhythmics: These medications help control irregular heartbeats.
  • Anticoagulants: e.g. warfarin, are used to prevent blood clots, particularly in patients with atrial fibrillation or artificial heart valves.
• Valve repair or replacement:
  • In severe cases of RHD, surgery may be necessary to repair or replace damaged heart valves.
  • Valve repair is preferred over replacement when possible, as it preserves the patient's own tissue.
  • Valve replacement involves replacing the damaged valve with a mechanical or biological valve.
• Other interventions:
  • Balloon valvuloplasty: This procedure can be used to open narrowed heart valves (stenosis) by inserting a balloon-tipped catheter into the valve and inflating it.
  • Management of heart failure: Patients with RHD may develop heart failure, which requires additional treatment with medications, lifestyle changes, and possibly surgery.

Complications

• Heart failure: The damaged heart valves can lead to heart failure, where the heart is unable to pump enough blood to meet the body's needs.
• Atrial fibrillation: RHD can increase the risk of developing atrial fibrillation, an irregular heartbeat that can lead to blood clots, stroke, and other complications.
• Stroke: Blood clots that form in the heart due to atrial fibrillation or valve abnormalities can travel to the brain, causing a stroke.
• Infective endocarditis: Damaged heart valves are more susceptible to infection, increasing the risk of infective endocarditis.
• Pulmonary hypertension: RHD can lead to increased pressure in the arteries of the lungs (pulmonary hypertension), which can cause shortness of breath and fatigue.
• Pregnancy complications: RHD can increase the risk of complications during pregnancy, such as heart failure, arrhythmias, and premature delivery.

Epidemiology

• RHD is most prevalent in low- and middle-income countries, where access to healthcare and treatment for strep throat is limited.
• Indigenous populations in developed countries, such as Australia and New Zealand, also experience a higher burden of RHD.
• The incidence of RHD has declined significantly in high-income countries due to improved access to healthcare and antibiotic treatment.
• RHD typically affects children and young adults, but the long-term consequences can persist throughout life.
• Women are more likely to be affected by RHD than men.

Impact

• RHD is a major cause of cardiovascular morbidity and mortality, particularly in developing countries.
• It can lead to significant disability, reduced quality of life, and premature death.
• The economic burden of RHD is substantial, due to the costs of treatment, hospitalization, and lost productivity.
• RHD has a disproportionate impact on vulnerable populations, perpetuating cycles of poverty and inequality.

Research directions

• Development of a vaccine against Streptococcus pyogenes to prevent initial infections.
• Improved diagnostic tools for early detection of ARF and RHD.
• More effective strategies for secondary prophylaxis to prevent recurrent strep infections.
• Novel therapies to repair or regenerate damaged heart valves.
• Strategies to improve access to healthcare and treatment for RHD in resource-limited settings.