28 Rheumatic Fever and Acquired Valvular Heart Diseases
With Christian J. Kellenberger and Kevin S. Roman
Definition and Etiologic Consideration
Rheumatic fever is a nonsuppurative diffuse inflammatory disease of connective tissue involving the heart, blood vessels, joints, central nervous system, and skin occurring as a delayed sequela postpharyngitis with rheumatogenic strains of group A β-hemolytic Streptococcus.
- • Jones criteria for diagnosis of acute rheumatic fever:
- – Major criteria: carditis, arthritis, chorea, erythema marginatum, subcutaneous nodules
- – Minor criteria: previous rheumatic fever, arthralgia, fever, elevated erythrocyte sedimentation rate, elevated white blood cell count, prolongation of PR interval, presence of C-reactive protein
- • Cardiac manifestations of acute rheumatic fever include pancarditis, pericarditis, and significant valvular inflammatory disease.
- • Approximately 25% of children with rheumatic fever develop chronic disease resulting in rheumatic heart disease due to thickening and scarring of the valves.
Acquired valvular heart disease:
- • Rheumatic heart disease is the most common cause often associated with mitral valve disease. Mitral valve involvement occurs in approximately 75% and aortic valve involvement in 25% of all rheumatic heart disease.
- • Infective endocarditis is a less common cause of acquired valvular heart disease, which may affect congenitally deformed valves and less commonly a normal valve.
- • Traumatic injury
- • Conditions dilating the ascending aorta can result in aortic valve disease. Etiologies include the following:
- – Aortitis from a variety of conditions
- – Cystic medial necrosis often in association with Marfan syndrome, Loeys-Dietz syndrome, and idiopathic annuloaortic ectasia or associated with hypertension and dissecting aneurysm.
- • Conditions dilating a ventricle can result in valvar regurgitation.
Pathophysiology
Rheumatic fever and rheumatic heart disease:
- • Postinfectious sequelae follow untreated pharyngitis with rheumatogenic strains of group A β-hemolytic Streptococcus. Susceptible host usually hypersensitized by repeated infections. Autoimmune response with antibodies, which cross-react with the organism and host tissues, causing tissue damage.
- • Carditis affects endocardium, myocardium, and pericardium, causing a pancarditis. Endocarditis involves mitral and aortic valves and rarely tricuspid or pulmonary valves.
- • Mitral regurgitation is the hallmark of acute rheumatic carditis in childhood.
- • Rheumatic endocarditis causes commissural fusion, thickened fibrous tissue, and calcification, leading to valvar stenosis and less commonly regurgitation.
- • Pulmonary arteriolar vasoconstriction develops to protect lung from congestion, which leads to pulmonary hypertension and right ventricular failure.
- • Aortic valve disease uncommon in childhood: scarred, thickened, and shortened leaflets, which are unable to coapt, resulting in aortic insufficiency.
- • Acquired aortic stenosis is a chronic sequela due to fibrosis, thickening, and fusion of commissures.
- • Very rare involvement of tricuspid and pulmonary valves
