Rheumatic
Heart Disease
Epidemiology and Etiology:
- Rheumatic heard
disease is cause of 99% of all mitral stenosis
- Hypersensitivity reaction
induced by group A streptococci (GAS)
- Children 5-15y
- Chronic rheumatic
heart disease manifests later:
- Years or decades
after rheumatic fever
Common sites:
- mitral valve virtually always involved in
chronic rheumatic heart disease
- mitral valve alone (65-70%)
- mitral and aortic valves (25%)
- similar but
generally less severe changes in tricuspid and rarely in pulmonic valves
Gross features:
- acute rheumatic
fever (RF):
- “bread-and-butter”
pericarditis
- fibrinous
or serofibrinous pericardial exudates
- 1-2mm
vegetations on line of closure of left-sided valve leaflets
- irregular
thickenings in the left atrium (MacCallum
plaques) (caused by regurgitant jets)
- chronic rheumatic
heart disease (RHD):
- left-sided valve
changes (“fish-mouth” or “buttonhole” stenoses):
- leaflet
thickening and shortening
- commissural
fusion
- thickening
and fusion of the tendinous cords
- dilated left
atrium
- secondary cor pulmonale over time
Histologic features:
- Acute rheumatic
fever (RF):
- Heart:
- Aschoff
bodies in any layer of the heart (pancarditis):
- Foci
of swollen eosinophilic collagen surrounded
by inflammatory cells:
- lymphocytes
(primarily T cells)
- occasional
plasma cells
- plump
macrophages (Anitschkow cells – pathognomonic for RF)
- abundant
cytoplasm
- central
round-to-ovoid nuclei
- chromatin
in a central, slender, wavy ribbon
- some
are multinucleated
- often
perivascular in myocardium
- fibrinoid
necrosis within the cusps of the left-sided valves or along the tendinous cords
- chronic rheumatic
heart disease:
- diffuse fibrosis
of valves
- neovascularization of leaflet (normally avascular)
- no Aschoff bodies (replaced by fibrous scar)
Immunophenotype:
Marker:
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Sensitivity:
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Specificity:
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Molecular features:
Other features:
- serum antibodies
present in most patients:
- rheumatic fever occurs 10d to 6wk following an
episode of GAS pharyngitis
(3%)
- Jones criteria:
- Preceding
GAS infection
- 2 major
or 1 major and 2 minor manifestations
- major
manifestations:
- migratory
polyarthritis of large joints
- carditis
- subcutaneous
nodules
- erythema
marginatum in the skin
- Sydenham
chorea
- Minor manifestations:
- Nonspecific
signs and symptoms
- Fever
- Arthralgia
- Elevated
acute phase reactants in blood
- Recurs with
subsequent pharyngeal infections
References: