Treatment of Rheumatic Carditis

Diagnostic Findings

Modality	Specific Clinical Findings
Auscultation	The hallmark is a pansystolic murmur of mitral regurgitation (best heard at the apex and radiating to the axilla). A high-pitched early diastolic decrescendo murmur indicates aortic regurgitation. An apical third heart sound (S3) gallop and a soft, delayed mid-diastolic murmur (Carey Coombs' murmur) indicate increased transmitral flow across inflamed valves. A pericardial friction rub (a scratchy sound with systolic, diastolic, and presystolic components) may be present if pericarditis accompanies the carditis.
Electrocardiogram (ECG)	Prolonged PR interval is a classic minor criterion but is not specifically diagnostic of carditis. Sinus tachycardia is common in the acute phase. If pericarditis is present, generalized ST-segment elevation may occur, evolving into isoelectric ST segments with T-wave inversions.
Echocardiography	Essential for detecting subclinical carditis. Acute changes include annular dilation, chordal elongation (leading to anterior leaflet prolapse and lack of coaptation), and beading/nodular thickening restricted to the leaflet tips. Color Doppler confirms pathological mitral regurgitation (jet length $\geq$ 2 cm, peak velocity >3 m/sec, pan-systolic) or aortic regurgitation (jet length $\geq$ 1 cm, peak velocity >3 m/sec, pan-diastolic).
Chest Radiograph (CXR)	Demonstrates cardiomegaly dependent on the severity of mitral or aortic regurgitation and left ventricular failure. Signs of pulmonary venous congestion and interstitial pulmonary edema may be present with acute decompensation.
Cardiac Catheterization	Left ventriculography visually outlines the regurgitant flow of contrast into the left atrium during systole; elevated pulmonary capillary wedge pressures with prominent 'V' waves are diagnostic of significant mitral regurgitation.

Medical Management

Eradication of Group A Streptococcus (GAS)

Regardless of throat culture results at the time of diagnosis, a therapeutic dose of antibiotics must be administered to eradicate any residual pharyngeal GAS carriage.
A single intramuscular injection of benzathine benzylpenicillin is highly effective.
Alternative regimens include oral Penicillin V (250 mg four times a day for 10 days) or azithromycin for patients with a documented penicillin allergy.

Anti-Inflammatory (Suppressive) Therapy

The choice between aspirin and systemic corticosteroids depends on the severity of the carditis and the presence of congestive cardiac failure (CCF).
In patients with carditis complicated by CCF, systemic corticosteroids are strictly indicated, as they are associated with lower mortality compared to aspirin.
In patients with carditis but without CCF, either steroids or aspirin can be used, although steroids are frequently preferred due to their rapid action in suppressing inflammation and resolving pericardial friction rubs (typically within 3 to 5 days).
Corticosteroid Regimen: Oral prednisolone is administered at 2 mg/kg/day (maximum dose of 60 mg) for 3 weeks, followed by a gradual taper over the subsequent 9 weeks.
Aspirin Regimen: Administered at 90-120 mg/kg/day in four divided doses for 10 weeks, and then tapered over the final 2 weeks.
The total duration of suppressive therapy for rheumatic carditis is generally 12 weeks.

Management of Congestive Heart Failure

Strict bed rest is recommended during the acute phase; prolonged bed rest (>2-3 weeks) is reserved for patients with clinically apparent carditis and active heart failure.
Management includes fluid restriction and conventional decongestive therapy using diuretics, such as furosemide.
The use of Angiotensin-Converting Enzyme (ACE) inhibitors is controversial in the acute setting but is widely utilized to decrease the regurgitant fraction and afterload in cases of severe mitral or aortic regurgitation.
Digoxin and beta-blockers may be cautiously considered, carefully guided by the patient's ventricular function and overall clinical stability.

Surgical Management

Surgical intervention is indicated in the acute phase if the patient rapidly deteriorates hemodynamically despite aggressive medical and decongestive measures.
Acute hemodynamic overload secondary to severe mitral or aortic regurgitation is the primary cause of mortality in acute rheumatic fever and may necessitate urgent valve repair or replacement.
Mitral valve repair is heavily favored over prosthetic replacement in the pediatric population to avoid the lifelong morbidities associated with mechanical valves (strict anticoagulation) and the inevitability of somatic growth outstripping the prosthetic valve.

Secondary Prophylaxis

Continuous secondary antibiotic prophylaxis is essential to prevent recurrent ARF episodes, which uniformly lead to progressive and cumulative valvular destruction.
The standard regimen is an intramuscular injection of Benzathine Penicillin G (1.2 million units for patients >30 kg; 600,000 units for <30 kg) every 3 to 4 weeks.

Patient Category	Duration of Prophylaxis (American Heart Association Guidelines)
ARF with carditis but NO residual valvular disease	For 10 years after the last ARF episode OR until age 21 years (whichever is longer).
ARF with carditis and residual heart disease (RHD)	For 10 years after the last ARF episode OR until age 40 years (whichever is longer); lifelong prophylaxis may be required for severe disease or post-valve surgery.