Transcript Rheumatic Fever and Heart Disease

Rheumatic heart disease
By
Dr. Abdelaty Shawky
Assistant professor of pathology
RHEUMATIC HEART DISEASE
• Rheumatic fever is a post-streptococcal immunemediated inflammatory disease affect heart and extracardiac sites e.g. joints, skin, brain….
• The incidence and mortality of rheumatic fever has
declined over the past 30 years (due to improved
socioeconomic condition and rapid diagnosis and
treatment of strep. pharyngitis).
* Pathogenesis:
• An acute attack of streptococcal pharyngitis by group A
beta-hemolytic streptococci.
• Within 2-4 weeks after this attack anti-streptococcal
antibodies are formed and attack the heart and the
extra-cardiac sites.
• The mechanism of this immune reaction is not yet
understood, however, the most accepted hypothesis is
antigenic similarity hypothesis.
Strep throat
Antibody
production
Antibody cross-reaction
with heart
vegetations
Aschoff body
pericarditis
* Pathological features of Rheumatic Heart
disease:
• The characteristic lesion of acute rheumatic fever is the
Aschoff body, consisting of a focus of necrosis
(representing the site of antigen – antibody reaction)
surrounded by activated histiocytes and lymphocytes.
The histiocytes may be mononuclear or multinuclear,
and are referred to as Anitschkow's or Aschoff cells.
• These foci may be found in the pericardium, the
myocardium, or uncommonly in the valves.
• They ultimately "heal" by fibrosis.
- The disease passes into two phases;
A. Acute phase:
 acute rheumatic pancarditis (inflammation of
endocardium, myocardium and pericardium)
1. Myocarditis.
2. Pericarditis: "bread and butter", due to fibrinous
inflammation
3. Endocarditis: edema, inflammation and fibrin
deposits on valve leaflets (vegetations) along lines of
closure. Mitral valve is commonly affected followed
by the aortic valve. Aschoff nodules are uncommon
in the valves.
B. Chronic phase:
Acute changes may resolve completely or progress to
scarring and development of chronic valvular deformities
many years after the acute disease.
Aschoff’s body
Rheumatic vegetations
Aortic valve stenosis
* Extra-cardiac lesions of rheumatic fever:
• These lesions are acute and resolve completely without
disability.
1. Migratory polyarthritis: It causes "fleeting arthritis" in
the large joints, self limited, no chronic deformities.
2. Skin: skin rheumatic nodules, erythema marginatum.
3. Sydenham chorea: a neurologic disorder with
involuntary purposeless, rapid movements.
Erythema marginatum
* Clinical features of Acute Rheumatic Fever:
• Occurs 10 days to 6 weeks after pharyngitis
• Peak incidence: 5-15 years.
• Cardiac manifestations: pericardial friction rubs, weak
heart sounds, tachycardia and arrhythmias.
• Extra-cardiac: fever, migratory polyarthritis of large
joints, arthralgia, skin lesions, chorea.
• Pharyngeal culture may be negative, but anti
streptolysin O (ASO) titer will be high.
* Jones criteria:
A. Major criteria:
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–
–
–
–
Carditis.
Polyarthritis
Sydenham’s chorea.
Erythema marginatum.
Subcutaneous nodules.
B. Minor criteria:
–
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Previous history of rheumatic fever.
Arthralgia.
Fever.
Lab tests indicative of inflammation : ESR (erythrocyte sedimentation
rate), CRP (C-Reactive protein), leukocytosis.
– ECG changes.
* Diagnosis of rheumatic fever:
• Need 2 major criteria or 1 major and 2 minor
criteria.
CHRONIC RHEUMATIC HEART DISEASE
- Endocarditis heals by progressive fibrosis. Chronic
scarring of the valves constitutes the most important
long-term sequelae of rheumatic fever, and usually
becomes clinically manifest decades after the acute
process.
• Left sided valves (mitral then aortic) are more
commonly involved than the right valves.
• Fibrosis of valve leaflets --> stenosis.
• Fibrosis of chordae tendonae --> regurgitation
(improper closure).
• Other cardiac complications:
1. Subacute bacterial endocarditis.
2. Arrhythmia.
3. Chronic heart failure.
• In valve stenosis:
 Leaflets are thickened, fibrotic, shrunken with fusion.
 Dilatation and hypertrophy of left atrium.
 Secondary deposition of Ca++
 fish mouth (button hole) stenosis - i.e. the stenosed
valve looks like a fish's mouth
 Lungs are firm and heavy (chronic passive
congestion).
 Pulmonary hypertension
 Right side of the heart may be affected later (right
ventricular hypertrophy).
• In valve incompetence (regurgitation):
– Retracted leaflets.
– Left ventricular hypertrophy and dilatation.
Mitral stenosis with commissural fusion