Acute rheumatic carditis

Overview Of Acute rheumatic carditis

Acute rheumatic carditis is a serious inflammatory condition of the heart that occurs as a complication of untreated or inadequately treated group A streptococcal (GAS) infections, such as strep throat or scarlet fever. It is a major manifestation of acute rheumatic fever (ARF), a systemic autoimmune response that can affect the heart, joints, skin, and brain. Rheumatic carditis primarily involves the endocardium, myocardium, and pericardium, leading to valvulitis, myocarditis, and pericarditis. The inflammation can cause permanent damage to the heart valves, particularly the mitral and aortic valves, resulting in chronic rheumatic heart disease (RHD). This condition is most common in children aged 5–15 years and remains a significant cause of cardiovascular morbidity and mortality in low- and middle-income countries.

Causes of Acute rheumatic carditis

• Acute rheumatic carditis is caused by an abnormal immune response to group A streptococcal (GAS) infections. Molecular mimicry plays a key role, where antibodies produced against streptococcal antigens cross-react with human tissues, particularly those in the heart. This autoimmune response leads to inflammation and damage to the heart valves, myocardium, and pericardium. Risk factors include poor access to healthcare, overcrowded living conditions, and delayed or inadequate treatment of streptococcal infections. Genetic predisposition may also contribute to susceptibility, as certain HLA alleles are associated with an increased risk of developing rheumatic fever and carditis.

Risk Factors of Acute rheumatic carditis

• Several factors increase the risk of developing acute rheumatic carditis:
• Untreated Streptococcal Infections: Inadequate treatment of GAS pharyngitis or scarlet fever is the primary risk factor.
• Age: Children aged 5–15 years are most susceptible.
• Genetic Predisposition: Certain HLA alleles, such as HLA-DR7 and HLA-DR4, are associated with increased susceptibility.
• Environmental Factors: Overcrowding, poor sanitation, and limited access to healthcare contribute to higher incidence rates.
• Previous Rheumatic Fever: A history of ARF or RHD increases the risk of recurrent episodes.
• Socioeconomic Status: Lower socioeconomic status is linked to higher rates of rheumatic carditis due to barriers to healthcare access.

Prevention of Acute rheumatic carditis

• Preventing acute rheumatic carditis involves primary and secondary prevention strategies:
• Primary Prevention: Prompt diagnosis and treatment of streptococcal pharyngitis with antibiotics, typically penicillin, to prevent rheumatic fever.
• Secondary Prevention: Long-term antibiotic prophylaxis (e.g., monthly penicillin injections) for patients with a history of rheumatic fever or RHD to prevent recurrence.
• Public Health Measures: Improving access to healthcare, reducing overcrowding, and promoting hygiene to decrease streptococcal transmission.
• Education: Raising awareness about the importance of completing antibiotic courses and recognizing symptoms of rheumatic fever.
• Vaccination: Development and implementation of a group A streptococcal vaccine could significantly reduce the incidence of rheumatic fever and carditis.

Prognosis of Acute rheumatic carditis

• The prognosis of acute rheumatic carditis depends on the severity of the initial episode, the extent of cardiac involvement, and the timeliness of treatment. Mild cases with prompt treatment may resolve without significant long-term sequelae. However, severe or recurrent episodes can lead to chronic rheumatic heart disease, characterized by progressive valvular damage, heart failure, and increased risk of infective endocarditis. Early diagnosis, adherence to antibiotic prophylaxis, and regular follow-up are critical to improving outcomes and preventing complications. Mortality rates are higher in low-resource settings due to delayed diagnosis and limited access to specialized care.

Complications of Acute rheumatic carditis

• Acute rheumatic carditis can lead to several complications, including:
• Chronic Rheumatic Heart Disease (RHD): Progressive valvular damage, particularly mitral and aortic stenosis or regurgitation.
• Heart Failure: Severe inflammation and valvular dysfunction can impair cardiac output.
• Infective Endocarditis: Damaged heart valves are more susceptible to bacterial infection.
• Arrhythmias: Conduction abnormalities or atrial fibrillation may occur due to myocardial inflammation.
• Pericardial Effusion: Inflammation of the pericardium can lead to fluid accumulation and cardiac tamponade.
• Stroke: Embolism from damaged valves can cause cerebrovascular events.

Related Diseases of Acute rheumatic carditis

• Acute rheumatic carditis is closely related to several other conditions, including:
• Rheumatic Fever: The systemic inflammatory condition of which carditis is a major manifestation.
• Chronic Rheumatic Heart Disease (RHD): The long-term sequela of recurrent or severe rheumatic carditis.
• Infective Endocarditis: A bacterial infection of the heart valves, often complicating RHD.
• Viral Myocarditis: Inflammation of the myocardium caused by viral infections, which can mimic rheumatic carditis.
• Post-Streptococcal Reactive Arthritis: A condition characterized by arthritis following streptococcal infection, without fulfilling the criteria for rheumatic fever. Understanding these related diseases aids in differential diagnosis and comprehensive management.

Treatment of Acute rheumatic carditis

The treatment of acute rheumatic carditis focuses on eradicating the streptococcal infection, reducing inflammation, and managing complications. Antibiotics, typically penicillin or an alternative for penicillin-allergic patients, are administered to eliminate residual streptococcal infection. Anti-inflammatory agents, such as aspirin or corticosteroids, are used to reduce cardiac inflammation and alleviate symptoms. In severe cases with heart failure, diuretics, ACE inhibitors, or other heart failure therapies may be required. Long-term secondary prophylaxis with penicillin is essential to prevent recurrent episodes of rheumatic fever and further cardiac damage. Surgical intervention, such as valve repair or replacement, may be necessary for patients with severe valvular damage.