Rheumatic fever-associated carditis - Symptoms, Causes, Treatment & Prevention

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Overview

Rheumatic fever‑associated carditis (often called rheumatic carditis) is an inflammatory disease of the heart that occurs as a complication of acute rheumatic fever (ARF). The inflammation can affect the myocardium (heart muscle), endocardium (inner lining, especially the heart valves), and pericardium (the sac surrounding the heart). When the valve leaflets become scarred, they may thicken or fuse, leading to long‑term “rheumatic heart disease.”

ARF is an autoimmune response that follows infection with Group A Streptococcus (GAS) bacteria, most commonly a throat infection (strep throat). While ARF can affect anyone, it is most prevalent in children aged 5–15 years, especially in low‑resource settings where streptococcal infections are common and access to antibiotics is limited.

Global burden: According to the World Health Organization (WHO), an estimated 33 million people worldwide have rheumatic heart disease, and >300 000 deaths occur each year, the majority of which are due to chronic valve damage that began as rheumatic carditis. In the United States, ARF is rare (<0.1 case per 1 000 person‑years) but still observed in certain high‑risk populations (e.g., Native American, Alaskan Native, and recent immigrants from endemic regions) <sup>[1][2]</sup>.

Symptoms

Symptoms reflect the part of the heart involved and can vary from mild to life‑threatening. In the acute phase, they often appear 2–4 weeks after the streptococcal infection.

• Fever – low‑grade to high fever (often >38 °C/100.4 °F).
• Chest pain – sharp, pleuritic pain that may improve when sitting up (pericardial involvement).
• Shortness of breath (dyspnea) – especially on exertion; may be due to heart failure from myocardial inflammation.
• Palpitations – irregular or rapid heartbeat caused by myocarditis or valvular regurgitation.
• Fatigue & weakness – result of reduced cardiac output.
• Peripheral edema – swelling of feet, ankles, or abdomen in severe cases of heart failure.
• Heart murmur – new or changing murmur heard on auscultation, most commonly regurgitant murmurs of the mitral or aortic valves.
• Joint pain & swelling – part of the broader Jones criteria for ARF, often migratory polyarthritis.
• Subcutaneous nodules and erythema marginatum – skin findings that support the diagnosis of ARF.
• Syncope (fainting) – can indicate severe arrhythmia or hemodynamic compromise.

Causes and Risk Factors

Underlying cause

Rheumatic carditis is an autoimmune reaction. After a throat infection with GAS, bacterial antigens (especially the M protein) cross‑react with proteins in the heart tissue—a process called “molecular mimicry.” The immune system mistakenly attacks the heart, causing inflammation.

Risk factors

• Age: 5–15 years old (peak incidence).
• Geography & socioeconomic status: Overcrowding, poor housing, limited access to health care, and low socioeconomic status raise risk.
• Population groups: Indigenous peoples of Australia, New Zealand, the Pacific Islands, parts of sub‑Saharan Africa, South Asia, and Central America.
• Previous streptococcal infection without prompt antibiotic treatment.
• Genetic predisposition: Certain HLA class II alleles (e.g., HLA‑DR7) are associated with increased susceptibility.
• Seasonality: Peaks in winter and early spring when streptococcal pharyngitis is most common.

Diagnosis

Diagnosing rheumatic carditis involves confirming acute rheumatic fever and then identifying cardiac involvement.

Clinical criteria (Jones criteria)

According to the 2015 revision of the Jones criteria, a diagnosis of ARF requires:

• Two major manifestations (e.g., carditis, polyarthritis, chorea, erythema marginatum, subcutaneous nodules) or
• One major + two minor manifestations (elevated ESR/CRP, fever, prolonged PR interval) plus evidence of a recent GAS infection (positive throat culture, rapid antigen test, or elevated ASO/anti‑DNAse B titers).

Cardiac assessment

• Physical examination: Detection of new murmurs, gallops, rubs, and signs of heart failure.
• Echocardiography (transthoracic): First‑line imaging. Detects valvular regurgitation, leaflet thickening, and pericardial effusion. Sensitivity >90 % for detecting early valve lesions <sup>[3]</sup>.
• Electrocardiogram (ECG): May show atrioventricular (AV) block, atrial fibrillation, or nonspecific ST‑T changes.
• Chest X‑ray: Can reveal cardiomegaly or pulmonary congestion in severe cases.
• Laboratory tests:
  • Elevated acute‑phase reactants (ESR, CRP).
  • Streptococcal serology (anti‑streptolysin O [ASO] or anti‑DNAse B titers).
  • Complete blood count – often shows mild leukocytosis.

Treatment Options

Treatment aims to eradicate the streptococcal infection, suppress the autoimmune inflammation, prevent recurrence, and manage cardiac complications.

Antibiotic therapy

• Pencillin V oral 250 mg twice daily for 10 days (or a single intramuscular dose of benzathine penicillin G 1.2 million IU) to eradicate GAS.
• If allergic to penicillin: Azithromycin 12 mg/kg once daily for 5 days or Clindamycin 7 mg/kg three times daily for 10 days.

Anti‑inflammatory therapy

• Aspirin (high‑dose 30–50 mg/kg/day divided q6h) for 2–4 weeks until fever and murmur improve. Then transition to low‑dose (3–5 mg/kg/day) for 6–12 months for secondary prophylaxis of rheumatic activity.
• Corticosteroids (e.g., Prednisone 1–2 mg/kg/day) are reserved for patients with severe carditis, heart failure, or those who do not respond to aspirin.

Heart‑failure management (if needed)

• Loop diuretics (furosemide) for pulmonary edema.
• ACE inhibitors or ARBs for afterload reduction.
• Beta‑blockers for tachyarrhythmias, once the patient is hemodynamically stable.

Long‑term secondary prophylaxis

Preventing recurrent GAS infection is crucial because each episode can worsen valve damage.

• Monthly intramuscular benzathine penicillin G (1.2 million IU for adults, 600 000 IU for children < 5 y) for ≥ 10 years or until age 21 (whichever is longer) after the first episode. For those with established rheumatic heart disease, prophylaxis continues for life.
• Or oral penicillin V twice daily if IM administration is not feasible.

Surgical/interventional options (chronic phase)

• Valve repair – Preferred when feasible, especially for mitral regurgitation with preserved leaflet tissue.
• Valve replacement – Mechanical or bioprosthetic valves for severe, irreversible stenosis or regurgitation. Anticoagulation is required for mechanical valves.
• Transcatheter mitral valve repair (e.g., MitraClip) is emerging in selected adult patients.

Lifestyle & supportive measures

• Low‑salt diet and fluid restriction if heart failure is present.
• Regular, moderate physical activity as tolerated; avoid strenuous exertion during acute inflammation.
• Vaccinations (influenza, pneumococcal, COVID‑19) to reduce secondary infections.

Living with Rheumatic Fever‑Associated Carditis

Patients often transition from an acute, time‑limited illness to a chronic condition (rheumatic heart disease). The following strategies help maintain heart health and quality of life.

Medication adherence

• Set reminders for monthly penicillin injections or daily oral antibiotics.
• Use a medication diary or pharmacy refill alerts.

Regular cardiac follow‑up

• Echo every 1–2 years (or sooner if symptoms change) to monitor valve function.
• Annual visits with a cardiologist experienced in valvular disease.

Self‑monitoring

• Track weight, swelling, and shortness of breath.
• Check pulse and blood pressure weekly; note any new murmur or irregular rhythm.

Activity & diet

• Follow a heart‑healthy diet rich in fruits, vegetables, whole grains, lean protein, and low in saturated fat.
• Stay hydrated but follow fluid limits if instructed for heart‑failure management.
• Engage in low‑impact aerobic exercise (e.g., walking, swimming) 3–5 times per week, as tolerated.

Education and support

• Join patient support groups (e.g., Rheumatic Fever Support Network) for shared experiences.
• Educate family members on recognizing worsening symptoms.

Prevention

Because rheumatic carditis is a sequela of untreated streptococcal throat infection, primary and secondary prevention are cornerstones.

Primary prevention

• Prompt treatment of strep throat with appropriate antibiotics.
• Public‑health measures: improving housing, reducing crowding, and ensuring access to primary care.
• School‑based sore‑throat screening programs in high‑risk areas.

Secondary prevention

• Adherence to long‑term antibiotic prophylaxis (see Treatment section).
• Regular medical review to ensure compliance and adjust dosing.
• Immediate treatment of any new sore throat or skin infection with antibiotics.

Complications

If inflammation is not adequately controlled or recurrent ARF episodes occur, the following complications may arise.

• Permanent valvular disease – Most common is mitral stenosis; aortic regurgitation can also develop.
• Heart failure – Resulting from severe valve dysfunction or chronic myocarditis.
• Arrhythmias – Atrial fibrillation, atrial flutter, or AV block.
• Stroke or systemic embolism – From atrial fibrillation or valve vegetations.
• Infective endocarditis – Damaged valves provide a nidus for bacterial colonization.
• Pulmonary hypertension – Secondary to chronic left‑sided heart disease.
• Pregnancy complications – Women with severe valve disease have higher risk of maternal cardiac decompensation and fetal growth restriction.

When to Seek Emergency Care

References

1. World Health Organization. “Rheumatic Heart Disease.” WHO Fact Sheet, 2021. https://www.who.int/news-room/fact-sheets/detail/rheumatic-heart-disease
2. Mayo Clinic. “Rheumatic fever.” Updated 2024. https://www.mayoclinic.org/diseases-conditions/rheumatic-fever/symptoms-causes/syc-20377030
3. Cleveland Clinic. “Rheumatic Fever and Rheumatic Heart Disease.” 2023. https://my.clevelandclinic.org/health/diseases/17325-rheumatic-fever
4. American Heart Association. “Rheumatic Heart Disease.” 2022. https://www.heart.org/en/health-topics/rheumatic-fever/rheumatic-heart-disease
5. National Institute of Health, National Heart, Lung, and Blood Institute. “Rheumatic Fever.” 2024. https://www.nhlbi.nih.gov/health/rheumatic-fever

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