Transcript Rheumatic Fever and Heart Disease

Rheumatic heart disease
Dr. Gehan Mohammed
Dr. Abdelaty Shawky
Endocarditis
* Types:
(1). Non-infective endocarditis
A. Rheumatic endocarditis.
B. Verrucous (libman sack) endocarditis: with SLE.
C. Non-Bacterial thrombotic endocarditis.
(2). Infective endocarditis
A. Acute Infective endocarditis
B. Sub-acute Infective endocarditis
Rheumatic endocarditis
RHEUMATIC HEART DISEASE
• Rheumatic fever is a post-streptococcal immunemediated 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. pharyngitis).
* Pathogenesis:
• An acute attack of streptococcal pharyngitis by
group A beta-hemolytic streptococci.
• Within 2-4 weeks after this attack antistreptococcal 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. Mostly mitral and aortic valves. 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.
* 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:
–
–
–
–
–
Carditis.
Polyarthritis
Sydenham’s chorea.
Erythema marginatum.
Subcutaneous nodules.
B. Minor criteria:
–
–
–
–
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 and aortic) are more
commonly involved than the right.
• 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 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 stenosis with commissural fusion
* 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.
Nonbacterial Thrombotic Endocarditis
NBTE
• 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 common, non-infective endocarditis
attributable to elevated levels of circulating
immune complexes may occur in patients with
systemic lupus erythematosus
Infective Endocarditis
* Definition: infection of the cardiac valves or
mural surface of the endocardium, resulting in the
formation septic vegetations (thrombi).
* Divided into:
a. Acute infective endocarditis.
b. Subacute infective endocarditis.
Acute infective endocarditis
* Etiology:
• Acute suppurative inflammation that affects
healthy valves.
• Organisms: Highly virulent as staph. Aureus,
strept.hemolyticus and gonococci.
* Lesions:
• Mitral & aortic valves are most commonly
affected. Tricuspid is affected in IV drug
abusers.
• The mural endocardium may be also
affected.
• The affected valve and mural endocardium
show acute suppurative inflammation +
vegetations.
• Vegetations are:
* N/E: multiple, large, yellowish, friable found
anywhere on the cusps.
* M/P: the vegetations consist of platelet, fibrin,
bacteria, numerous neutrophils & pus cells.
• Myocardial shows microabscesses.
• The pericardial sac is filled with pus.
* Complications:
1. Embolic complications:
• Detached septic vegetations leads to systemic
pyemia.
2. Toxemic complications:
• Severe toxemia
* Prognosis:
• Rapidly fatal due to;
1. Severe toxemia (septicemia).
2. Cusp perforation (acute heart failure).
Subacute infective endocarditis
* Etiology:
• Subacute inflammation that affects abnormal
valves in;
Rheumatic valvulitis
Congenitally abnormal valves.
Prosthetic valves.
• Caused by Less virulent bacteria as
strept.viridans.
* Lesions:
• Mitral & aortic valves are commonly
affected.
• The mural endocardium may be also
affected
• The affected valve and the mural
endocardium show; the lesion of the
corresponding disease (e.g. rheumatic,
congenital) + vegetations.
• Vegetations are:
* N/E: multiple, large, gray, friable found
anywhere on the cusps.
* M/P: the vegetations consist of platelets, fibrin,
bacteria and some inflammatory cells mainly
histiocytes.
• The Myocardium shows degenerative changes.
* Complications:
1. Embolic complications:
• Infarctions: in kidney, spleen and brain, retina,
heart.
• Mycotic aneurysms: mainly in cerebral and
mesenteric.
• Petechial hemorrhage: in skin, mucous
membranes and serous membranes.
• Osler’s nodules: small. tender, intracutaneous
nodules in pulps of fingers & toes.
2. Toxemic complications:
• Moderate toxemia: fever, anemia, clubbing of
fingers, splenomegaly, petechial hemorrhage
and focal glomerulonephritis (flea bitten
kidney)
* Prognosis:
• Heal by fibrosis leads to valve lesion either
stenosis or incompetence.
Endocarditis of the mitral valve (subacute, caused by Streptococcus
viridens). vegetations are denoted by arrows.
C. Histologic appearance of vegetation of endocarditis with extensive acute inflammatory cells and fibrin. Bacterial organisms were
demonstrated by tissue Gram stain.
Slide 13.42
References:
Robbins and Cotran’s: Pathologic Basis of Disease. Seventh
edition.
Thanks