Rheumatic heart diseaseRheumatic heart disease

ByByDr. Abdelaty ShawkyDr. Abdelaty Shawky

Assistant professor of pathologyAssistant professor of pathology

RHEUMATIC HEART DISEASERHEUMATIC HEART DISEASE

• 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. 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.

vegetations Aschoff body pericarditis

Strep throatAntibody production

Antibody cross-reaction with heart

* 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 vegetationsRheumatic 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: * Jones criteria: A. Major criteria:A. Major criteria:– Carditis. – Polyarthritis – Sydenham’s chorea.– Erythema marginatum. – Subcutaneous nodules.

B. Minor criteria: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 DISEASECHRONIC 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