Myocarditis (Rheumatic Fever)

Myocarditis (Rheumatic Fever) is an inflammation of the heart muscle that occurs as a complication of a throat infection caused by the bacteria Streptococcus pyogenes. This condition primarily affects the heart, especially the myocardium, which is the muscular layer responsible for pumping blood. The inflammation can cause symptoms such as chest pain, shortness of breath, and irregular heartbeats. It may also lead to long-term damage to the heart valves, resulting in heart valve disease. The condition is part of a broader illness called rheumatic fever, which can affect multiple body systems including the joints and skin. Early recognition is important because the heart damage can be serious and sometimes permanent.

Myocarditis (Rheumatic Fever) is a form of myocarditis caused by an autoimmune reaction following infection with Group A Streptococcus (GAS). The core pathology involves immune-mediated inflammation of the myocardium triggered by molecular mimicry between streptococcal antigens and cardiac tissue. This leads to infiltration of the myocardium by T cells and macrophages, with characteristic Aschoff bodies seen on histology. The condition is a major component of acute rheumatic fever, which can cause pancarditis involving the endocardium, myocardium, and pericardium. Clinically, it is significant because it can cause heart failure, arrhythmias, and chronic rheumatic heart disease due to valve scarring. The diagnosis is supported by evidence of recent streptococcal infection and clinical criteria.