Write a short note on chronic rheumatic heart disease.

Definition

Chronic rheumatic heart disease (RHD) is permanent valvular damage resulting from one or more episodes of acute rheumatic fever, caused by the immune response to group A streptococcal pharyngitis. It remains the commonest form of acquired heart disease in children and young adults in India, and a leading cause of cardiac morbidity and premature death.

(The acute illness — acute rheumatic fever, the Jones criteria and secondary prophylaxis regimens — is covered in the Immunology & Rheumatology chapter. This answer deals with the chronic valve disease that follows.)

Pathogenesis of Chronic Valve Damage

Acute valvulitis causes oedema and verrucous vegetations along the line of closure. Over years, repeated inflammation and healing produce fibrosis, commissural fusion, chordal shortening and thickening, and calcification — converting a pliable valve into a rigid, stenotic and often regurgitant structure. Recurrent attacks of rheumatic fever accelerate this process, which is precisely why secondary prophylaxis matters more than any other intervention.

Valve involvement, in order of frequency:

• MITRAL VALVE — 70–80% (the most commonly affected)
• Aortic valve — 20–30%, usually with mitral involvement
• Tricuspid — uncommon and usually functional (secondary to right ventricular dilatation) rather than organic
• Pulmonary — very rare

Mitral stenosis is the classic and commonest chronic lesion, and the interval from acute rheumatic fever to symptomatic stenosis is typically 10–20 years — though it can be shorter in India, with severe disease appearing in adolescence ("juvenile mitral stenosis").

Clinical Features

• Often a silent latent period of years, with the patient presenting only when the valve lesion becomes haemodynamically significant.
• Symptoms of the specific valve lesion — exertional dyspnoea, orthopnoea, PND, fatigue, palpitations, haemoptysis (see the valvular heart disease answer).
• Atrial fibrillation — very common with mitral disease; often the presenting event, and a major cause of decompensation and stroke.
• Systemic embolism and stroke — a leading cause of disability, particularly in young women.
• Right heart failure — raised JVP, hepatomegaly, ascites, peripheral oedema — from pulmonary hypertension.
• Infective endocarditis superimposed on the damaged valve.
• Pregnancy — the increased blood volume and heart rate frequently unmask previously silent mitral stenosis, and RHD is a leading cause of maternal cardiac death in India.
• Growth retardation in children with severe long-standing disease.

Investigations

• ECHOCARDIOGRAPHY — the key investigation: identifies the valves involved, quantifies stenosis and regurgitation, assesses chamber size, ventricular function, pulmonary artery pressure and left atrial thrombus. It also detects subclinical rheumatic valve disease, which is the basis of echo-based screening programmes in endemic areas.
• ECG: P mitrale, atrial fibrillation, right or left ventricular hypertrophy.
• Chest X-ray: left atrial enlargement (double right heart border, splayed carina), pulmonary venous congestion, valve calcification, cardiomegaly.
• Bloods: CBC, ESR/CRP (to detect ongoing rheumatic activity), ASO titre, blood cultures if endocarditis is suspected, renal and liver function.
• Cardiac catheterisation — where echocardiography is inconclusive or before surgery in older patients (to assess the coronaries).

Management

1. SECONDARY PROPHYLAXIS — the single most important intervention

• Continuous antibiotic prophylaxis (intramuscular benzathine penicillin every 3–4 weeks, or oral penicillin) prevents recurrent attacks of rheumatic fever, each of which worsens valve damage.
• Duration depends on the presence of carditis and residual valve disease, and is often continued to the age of 40 or lifelong in established RHD (see the acute rheumatic fever answer for the schedule).
• Adherence over decades is the central practical challenge, and defaulting is the commonest reason for progressive valve destruction in Indian patients.

2. Medical management of the valve lesion and its complications

• Heart failure: diuretics, ACE inhibitors (caution in severe mitral or aortic stenosis), and salt restriction.
• Atrial fibrillation: rate control (beta-blocker, digoxin) and ANTICOAGULATION WITH WARFARIN — direct oral anticoagulants are NOT recommended in rheumatic mitral stenosis or with mechanical valves, a distinction of major practical importance.
• Infective endocarditis prophylaxis for the highest-risk patients, and meticulous dental hygiene for all.
• Treat anaemia, correct nutrition, and manage arrhythmias.

3. Intervention

• Percutaneous balloon mitral valvotomy — the treatment of choice for suitable mitral stenosis: pliable non-calcified valve, minimal regurgitation, no left atrial thrombus. It is relatively low-cost, avoids sternotomy, and is well suited to the young Indian patient population.
• Surgical valve repair or replacement — for unsuitable anatomy, mixed lesions, or predominant regurgitation. Mechanical valves last longer but require lifelong warfarin; bioprosthetic valves avoid anticoagulation but degenerate, which is a critical consideration in young women planning pregnancy, where warfarin is teratogenic — a decision requiring careful counselling.

4. Pregnancy and RHD

Pre-pregnancy counselling and risk assessment; balloon valvotomy before conception where indicated; joint cardiology-obstetric care; and careful anticoagulation planning, since warfarin is teratogenic in the first trimester but heparin gives poorer valve protection — a genuinely difficult balance requiring specialist management.

5. PREVENTION — the answer at population level

• Primary prevention: prompt diagnosis and antibiotic treatment of streptococcal sore throat, improved housing and reduced overcrowding, better nutrition and access to care.
• Secondary prevention: registers of RHD patients with organised delivery of penicillin prophylaxis — the model that has succeeded in other countries.
• Echo-based screening to detect subclinical disease in high-prevalence school populations.