Acute Rheumatic Carditis

Acute rheumatic carditis is pancarditis (endocarditis, myocarditis, pericarditis) complicating acute rheumatic fever, an autoimmune response to group A streptococcal pharyngitis in genetically susceptible hosts via molecular mimicry.

Acute rheumatic fever incidence is highest in children aged 5 to 15 years in low income regions; carditis occurs in 50 to 70% of first episodes.

Mitral valve is involved in nearly all, aortic valve in 20 to 30%.

Chronic rheumatic heart disease results from recurrent episodes, causing mitral stenosis and regurgitation, aortic disease.

Severe carditis can cause heart failure and death.

• Onset 2 to 4 weeks after streptococcal pharyngitis: fever, migratory polyarthritis, tachycardia out of proportion to fever.
• Valvulitis: apical pansystolic murmur of mitral regurgitation, Carey Coombs mid diastolic murmur, aortic regurgitation murmur.
• Myocarditis: heart failure, gallop, cardiomegaly; pericarditis: rub, effusion.
• Other major signs: Sydenham chorea, erythema marginatum, subcutaneous nodules.

Revised Jones criteria (2015)

• Evidence of preceding streptococcal infection (raised or rising ASO or anti DNase B, positive throat culture or rapid antigen) plus 2 major criteria or 1 major and 2 minor.
• Major (low risk populations): carditis (clinical or subclinical), arthritis (polyarthritis), chorea, erythema marginatum, subcutaneous nodules. High risk populations include monoarthritis and polyarthralgia as major.
• Minor: fever (38.5 C or more), arthralgia, ESR 60 mm/h or more or CRP 3 mg/dL or more, prolonged PR interval.
• Echocardiography with Doppler detects subclinical carditis (pathological regurgitation, valve thickening). ECG: first degree AV block. Chest radiograph: cardiomegaly. Troponin and BNP for myocarditis.

• Eradicate streptococci: benzathine penicillin G 1.2 million units IM single dose (600,000 units if under 27 kg), or phenoxymethylpenicillin 250 to 500 mg two to three times daily for 10 days; azithromycin 500 mg then 250 mg for 4 days in penicillin allergy.
• Bed rest until inflammation settles; gradual mobilisation.
• Anti inflammatory therapy:
  • Mild or no carditis: aspirin 80 to 100 mg/kg/day in 4 divided doses (adults 4 to 8 g/day) for 2 to 4 weeks, tapering over 4 to 8 weeks, with salicylate monitoring.
  • Moderate to severe carditis with heart failure: prednisolone 1 to 2 mg/kg/day (maximum 80 mg) for 2 to 3 weeks, tapered over 2 to 3 weeks with aspirin overlap.
• Heart failure: furosemide 1 to 2 mg/kg, ACE inhibitor, digoxin cautiously (sensitivity of inflamed myocardium), oxygen.
• Chorea: valproate 15 to 20 mg/kg/day, carbamazepine, or haloperidol 0.5 to 1 mg; avoid steroids for chorea alone.
• Surgery in the acute phase for refractory heart failure due to severe regurgitation (valve repair preferred).
• Secondary prophylaxis (essential): benzathine penicillin G 1.2 million units IM every 3 to 4 weeks (every 3 weeks in high risk), or penicillin V 250 mg twice daily. Duration: 10 years or until age 21 (whichever is longer) without carditis; 10 years or until age 40 with carditis or healed carditis; lifelong for severe valve disease or after valve surgery.
• Echocardiography follow up annually. Primary prevention by treating streptococcal pharyngitis.