What is the definition, signs, and symptoms of Rheumatic Heart Disease (RHD)?

Definition, Signs, and Symptoms of Rheumatic Heart Disease (RHD)

Rheumatic heart disease (RHD) is an autoimmune sequela of group A β-haemolytic streptococcal (GAS) infection of the throat (streptococcal pharyngitis) that causes damage to heart valves, leading to valvular heart disease, primarily affecting the mitral and aortic valves. 1

Definition and Pathophysiology

RHD results from an abnormal autoimmune response to a group A streptococcal infection in a genetically susceptible host. The disease process follows this sequence:

1. Initial GAS pharyngitis (or possibly skin infection)
2. Acute rheumatic fever (ARF) develops 2-3 weeks after the infection
3. Immune-inflammatory injury to cardiac valves
4. Progressive valve damage with recurrent ARF episodes
5. Development of chronic valvular heart disease

Epidemiology

• RHD remains the most common cardiovascular disease in young people under 25 years worldwide 1
• Causes approximately 250,000 deaths annually 2
• Predominantly affects children and young adults in low-income countries and disadvantaged populations
• Has been nearly eradicated in high-income regions but may be increasing due to migration patterns 1

Clinical Manifestations

Signs of RHD

1. Cardiac Murmurs:

   • Pathological mitral regurgitation (pansystolic murmur)
   • Pathological aortic regurgitation (early diastolic murmur)
   • Mitral stenosis (diastolic rumble with presystolic accentuation)

2. Echocardiographic Findings 1:

   • Mitral Valve Abnormalities:

     • Anterior mitral valve leaflet thickening ≥3 mm
     • Chordal thickening
     • Restricted leaflet motion
     • Excessive leaflet tip motion during systole

   • Aortic Valve Abnormalities:

     • Irregular or focal thickening
     • Coaptation defect
     • Restricted leaflet motion
     • Prolapse

3. Definite RHD is diagnosed when one of these criteria is met 1:

   • Pathological mitral regurgitation AND at least two morphological features of RHD of the mitral valve
   • Mitral stenosis with mean gradient ≥4 mmHg AND at least two morphological features
   • Pathological aortic regurgitation AND at least two morphological features of RHD of the aortic valve
   • Borderline disease of both the aortic valve and mitral valve

Symptoms of RHD

Symptoms vary depending on the stage and severity of valve damage:

1. Early/Mild Disease:

   • Often asymptomatic (subclinical RHD)
   • May have no detectable murmur without echocardiography

2. Progressive Disease:

   • Fatigue
   • Reduced exercise tolerance
   • Shortness of breath with exertion
   • Palpitations

3. Advanced Disease:

   • Dyspnea at rest
   • Orthopnea
   • Paroxysmal nocturnal dyspnea
   • Chest pain
   • Hemoptysis (in mitral stenosis)
   • Peripheral edema
   • Syncope

Complications

RHD can lead to serious complications including:

• Heart failure
• Atrial fibrillation
• Stroke
• Infective endocarditis
• Pregnancy-related complications
• Premature death (in some studies, mean age of death <25 years) 1

Diagnostic Approach

1. Clinical Assessment:

   • History of ARF or GAS pharyngitis
   • Cardiac auscultation for pathological murmurs

2. Echocardiography (gold standard):

   • Standard echocardiography is the preferred diagnostic tool
   • Handheld echocardiography shows excellent discrimination for cases of RHD in screening settings 1
   • Echocardiographic findings should be interpreted according to the 2012 World Heart Federation criteria 1

3. Laboratory Tests:

   • Evidence of recent streptococcal infection (elevated ASO titers, anti-DNase B)
   • Inflammatory markers (elevated ESR, CRP)

Important Considerations

• RHD is often underdiagnosed in its early stages when intervention could prevent progression 3
• Many patients present late with advanced disease (62-82.5% presenting with severe disease in some regions) 4
• Echocardiographic screening can detect subclinical RHD, allowing for early intervention 2
• The disease primarily affects the mitral valve, with the aortic valve being the second most commonly affected 1

Common Pitfalls to Avoid

1. Misdiagnosis: Failing to differentiate RHD from other causes of valve disease (congenital, degenerative, etc.)
2. Delayed Diagnosis: Missing early, subclinical RHD when intervention could prevent progression
3. Incomplete Assessment: Not performing comprehensive echocardiography according to established criteria
4. Inadequate Follow-up: Failing to monitor patients with borderline RHD for disease progression

Early detection and appropriate management with secondary prophylaxis are crucial for preventing the progression of valve damage and reducing morbidity and mortality associated with RHD.