ESSENTIALS OF DIAGNOSIS
More common in developing countries (100 cases/100,000 population) than in the United States (~2 cases/100,000 population).
Peak incidence between ages 5 and 15 years.
Revision of Jones criteria in 2015 includes echocardiographic findings.
May involve mitral and other valves acutely, rarely leading to heart failure.
Rheumatic fever is a systemic immune process that is a sequela of a beta-hemolytic streptococcal infection of the pharynx. It is a major scourge in developing countries and responsible for 320,000 deaths in young people worldwide each year. Over 15 million people have evidence for rheumatic heart disease. Some experts believe molecular mimicry between streptococcal helical surface antigens and similar shaped human proteins on the valvular leaflets and in the myocardium (actin-myosin) are at the core of the problem. There is also a clear genetic predisposition. The elucidation of chemokines and their receptors involved with the recruitment of T cells, as well as the function of T regulatory cells, likely contributes to the heart lesion responsible for rheumatic heart disease. Pyodermic streptococcal infections on the skin are not associated with rheumatic fever. Signs of acute rheumatic fever usually commence 2–3 weeks after infection but may appear as early as 1 week or as late as 5 weeks. The disease has become quite uncommon in the United States, except in immigrants. The peak incidence is between ages 5 and 15 years; rheumatic fever is rare before age 4 years or after age 40 years. Rheumatic carditis and valvulitis may be self-limited or may lead to slowly progressive valvular deformity. The characteristic lesion is a perivascular granulomatous reaction with valvulitis (eFigure 10–78). The mitral valve is acutely attacked in 75–80% of cases, the aortic valve in 30% (but rarely as the sole valve involved), and the tricuspid and pulmonary valves in under 5% of cases.
Aschoff nodule. Reacting lymphocytes and large mononuclear cells in myocardium demonstrate a cellular component to the immune reaction in rheumatic fever. (Reproduced, with permission, from Ryan KJ. Sherris Medical Microbiology, 7th ed. McGraw-Hill, 2018.)
The clinical profile of the infection includes carditis in 50–70% and arthritis in 35–66%, followed by chorea (10–30%, predominantly in girls) then subcutaneous nodules (0–10%) and erythema marginatum (in less than 6%). Echocardiography has been found to be superior to auscultation, and the 2015 guidelines introduced subclinical carditis to the Jones criteria to represent abnormal echocardiographic findings when auscultatory findings were either not present or not recognized.
Chronic rheumatic heart disease results from single or repeated attacks of rheumatic fever that produce rigidity and deformity of valve cusps, fusion of the commissures, or shortening and fusion of the chordae tendineae. Valvular stenosis or regurgitation results, and the two often coexist. In chronic rheumatic heart disease, the mitral valve alone is abnormal in 50–60% of cases; combined lesions of the ...