Rheumatic heart disease Ali Al Khader, M.D. Faculty of Medicine Al-Balqa’ Applied University Email: ali.alkhader@bau.edu.jo

What will we discuss today? Etiology and epidemiology of rheumatic heart disease Pathogenesis of rheumatic heart disease Morphological changes in rheumatic heart disease Clinical manifestations

Etiology & overview Rheumatic fever (RF) …acute Few weeks Rheumatic fever (RF) …acute …immunologically mediated …multisystem disease Pharyngitis (mainly but not only) Group A streptococcus …a common manifestation of active RF is: …acute rheumatic carditis The main cardiac abnormalities in this condition are in ………..??? may progress to chronic rheumatic heart disease… = RHD

Epidemiology Mortality & incidence of RF and RHD have significantly declined in many parts of the world….Why?

Pathogenesis Acute RF results from: immune reaction…cross-reactivity Antibodies and CD4+ T cells…damage heart tissue Antigens: M protein and cardiac self antigens (cross-reactivity)

Pathogenesis, cont’d Activation of complement T cells (mainly CD4+) They recognize streptococcal M proteins (cross-react with cardiac self antigens) by T cell receptors (TCRs) Activation of complement stimulate B cells to secrete: T cells (mainly CD4+) Antibodies Opsonization -Cytokine release -Activation of macrophages in Aschoff bodies

Morphology In acute rheumatic fever: …foci of inflammation in various tissues …especially in the heart…we find: Aschoff bodies = T cells + occasional plasma cells + activated macrophages Pathognomonic for RF = Anitschkow cells -plump -abundant cytoplasm -central round-to-ovoid nuclei…occasionally binucleate -chromatin condenses into a central, slender, wavy ribbon…so they are called: caterpillar cells Visit https://en.wikipedia.org/wiki/Caterpillar For references Visit https://en.wikipedia.org/wiki/Anitschkow_cell for references

Morphology of acute RF, cont’d Diffuse inflammation and Aschoff bodies may be found in any of the three layers of the heart …pericarditis, myocarditis or endocarditis …pancarditis little disturbance in cardiac function Mainly: scattered Aschoff bodies in the interstitium Mainly: fibrinous exudate …self-limited = valvular involvement: fibrinoid necrosis and fibrin deposition along the lines of closure…verrucae (vegetations)

Acute on top of chronic RHD…an example Small vegetations (1-2 mm) Robbins basic pathology 9th edition

Morphology of chronic rheumatic heart disease Organization…scarring Aschoff bodies are replaced by fibrous scars…also there is calcification Valve cusps & leaflets…permanently thickened and retracted …especially: mitral valve Robbins basic pathology 9th edition (E, From Schoen FJ, St John-Sutton M: Contemporary issues in the pathology of valvular heart disease. Hum Pathol 18:568, 1967.)

Mitral stenosis in chronic RHD

Clinical notes, acute RF Mainly children…carditis 20%: in adults…arthritis more In all ages: 2-3 weeks after streptococcal infection: …fever + migratory polyarthritis…then spontaneous resolution …then: pericarditis, myocarditis or endocarditis…or pancarditis < 1% mortality Pericardial friction rub Can be so severe to cause mitral insufficiency and congestive heart failure arrhythmias

Clinical notes, acute RF…cont’d Cultures are negative Serum antibodies against one or more streptococcal antigens (streptolysin O, DNAse..etc.) are positive For diagnosis: serologic evidence of previous streptococcal infection + 2 or more of the major Jones criteria (1) carditis (2) migratory polyarthritis of large joints (3) subcutaneous nodules (4) erythema marginatum skin rashes (5) Sydenham chorea (also called St. Vitus dance) *Minor criteria: -fever -arthralgias -ECG changes -elevated acute phase reactants

Clinical notes, chronic RHD Valvular stenosis and regurgitation…predominantly stenosis …70%: mitral alone …25%: mitral + aortic …tricuspid…much less frequently …pulmonic…almost always spared …with time…left atrial dilation and atrial fibrillation…mural thrombus …with time…a picture similar to left sided heart failure…followed by rt. sided failure …What about left ventricle?? Murmurs

Clinical notes, chronic RHD Recurrent attacks with recurrent streptococcal infections …cumulative damage Chronic disease…after years/decades Scarred and deformed valves are more susceptible to infective endocarditis

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