9. Rheumatic heart disease. Rheumatic endocarditis, morphological stagies. Rheumatic myocarditis and pericarditis.

Rheumatic myocarditis histology

Rheumatic Myocarditis: gross appearance of the heart is relatively unremarkable, with only modest dilatation and mural softening. Rheumatic myocarditis is classified into:Granulomatous and Diffuse nonspecific myocarditis associated with a variable amount of myocyte necrosis and interstitial chronic inflammation.

Granulomatous Rheumatic Myocarditis: Is presented by Aschoff bodies in the heart interstitium - with perivascular & subendocardial localization. They can be found in the heart long after the clinical signs of disease have resolved.

Rheumatic Myocarditis- classed into granulomatous and diffuse non-specific

• Gross: dilatation and mural softening
• Micro: variable amount of myocyte necrosis and interstitial chronic inflammation
• Granulomatous rheumatic myocarditis → Aschoff bodies in the heart interstitium (perivascular + subendocardial localization)
• Prominent fibrinous pericarditis → fibrous organization of pericardium → Rheumatic pericarditis

Rheumatic Pericarditis: A prominent fibrinous pericarditis often is present, which may lead to fibrous organization that is of little significance.

Point out the stages in rheumatic endocarditis. (Essay 9)

Rheumatic carditis Defined as: type of pancarditis affecting all layers of heart, endocarditis occurs in all patients with RC whereas myocarditis and pericarditis are present in severe cases. Characterized by: Lipid deposition & fibrosis of the intima. Endocarditis (valvulitis): immunologically mediated disease caused by 2ⁿᵈ and 3ʳᵈ hypersensitivity reactions, valves of left heart are Affected more than right, and mitral more than aortic

4 types of endocarditis

1. I. Diffuse valvulitis (Endocarditis recens, incipiens)

• Diffuse mucoid degeneration of valvular cusps w/out any damage to endothelium, after healing cusps they thicken and become firm but no sign of deformation

Morphological stages

1. Mucoid edema of connective tissue
2. Fibrinoid degeneration of collagen
3. Aschoff granulomas
4. Fibrosis
5. II. Verrucous endocarditis (Endocarditis verrucose)

• valves show small foci of fibroid degeneration, ashchoff bodies, necrosis of collagen, denudation of endocardial lining

1. III. Fibrous endocarditis (Endocarditis fibrosa)

• Valve leaflets become fibrosis + thickening + neo-vascularization → fusing & calcification + thickening, shortening and fusing of chordae tendineae

1. IV. Recurrent endocarditis

• Characterized by fibrosis & acute connective tissue damage with fresh warty vegetations due to new attack of RF