Rheumatic fever is a post-streptococcal immune-mediated

Rheumatic fever is a post-streptococcal immune-mediated
inflammatory disease affect heart and extra-cardiac 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.
An acute attack of streptococcal pharyngitis by group A betahemolytic 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
* 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
3. Endocarditis: edema, inflammation and fibrin
deposits on valve leaflets (vegetations) along lines of
closure. Mostly mitral and
aortic valve. Aschoff nodules are uncommon in the
B. Chronic phase:
Acute changes may resolve completely or progress to scarring
and development of chronic valvular deformities many years
after the acute disease.
* Extra-cardiac lesions of rheumatic fever:
These lesions are acute and resolve completely without
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.
* 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:
Sydenham’s chorea.
Erythema marginatum.
Subcutaneous nodules.
B. Minor criteria:
Previous history of rheumatic 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.
- 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 and aortic) are more commonly
involved than the right.
• Fibrosis of valve leaflets --> stenosis.
• Fibrosis of chordae tendonae --> regurgitation (improper
• Other cardiac complications:
• Subacute bacterial endocarditis.
• Arrhythmia.
• Chronic heart failure.
• In valve stenosis:
Leaflets are thickened, fibrotic, shrunken with fusion
Dilatation and hypertrophy of left atrium (atrial fibrillation).
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 valve stenosis:
• Leads to left atrial dilatation and failure, chronic venous
congestion of the lung, lung fibrosis, pulmonary
hypertension and chronic right sided heart failure.
* Mitral valve incompetence:
• Leads to left ventricular dilatation and failure, left atrial
dilatation and failure, chronic pulmonary congestion, lung
fibrosis, pulmonary hypertension and chronic right sided
heart failure.
• Characterized by the deposition of small masses of
fibrin, platelets, and other blood components on
the leaflets of the cardiac valves. There is no
infective organism (sterile).
• Aortic valve is most common site.
• Clinically: asymptomatic, if large: may embolize.
* Pathogenesis/ association:
– Subtle endothelial abnormalities.
– Hypercoagulability.
– Association with malignancy (50%).
Verrucous (Libman-Sacks) endocarditis
• Less
attributable to elevated levels of circulating
immune complexes may occur in patients with
systemic lupus erythematosus