Rheumatic heart disease

Background

• Delayed autoimmune reaction to group A streptococcal pharyngitis

Pathophysiology

• Cross-reactivity of anti-streptococcal antibodies with interstitial cardiac valvular cells

Epidemiology

• Occurs in about 3% of cases of untreated streptococcal pharyngitis

Clinical Manifestations

• Almost always affects the mitral valve with isolate mitral stenosis being the most common
• Mitral regurgitation, aortic stenosis, and aortic regurgitation also possible
• Acute rheumatic fever can cause inflammation of essentially any part of the heart

Investigations

• Anti-streptolysin-O titre (ASOT)
  • >116 is suggestive of recent group A streptococcal infection

Complications

• Carditis leading to rheumatic heart disease in 30-45% of cases

Management

• Acute
  • Antibiotics
    • First-line: penicillin V for 10 days
    • Alternative: amoxicillin for 10 days
  • If carditis, add antiinflammatory
    • First-line: high-dose ASA 20mg/kg?? (~1.3g) po qid
    • Alternative: prednisone 1g/kg po daily with a 9-week taper
• Prophylaxis, including patients with mild latent disease on echo
  • Benzathine penicillin G 1.2mU IM q3-4week