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Introduction. Acute rheumatic fever: inflammatory disease with devastating sequelae.Link to pharyngeal infection with group A beta hemolytic Streptocci.Continues to be a problem worldwide:sporadic outbreaks in developed countries.frequent occurrences in developing countries.Best prevention stil
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1. MOSA FAGIH MBBS FRCPC FCAP
Department of Pathology & Clinical Laboratory Medicine.
Acute Rheumatic Fever
2. Introduction Acute rheumatic fever: inflammatory disease with devastating sequelae.
Link to pharyngeal infection with group A beta hemolytic Streptocci.
Continues to be a problem worldwide:
sporadic outbreaks in developed countries.
frequent occurrences in developing countries.
Best prevention still correct use of antibiotics.
3. Acute Rheumatic Fever Epidemiology
Pathogenesis
Clinical features
Diagnosis
Treatment
4. Epidemiology Important cause of chronic disease and death in developing world.
Underdiagnosed and undertreated.
5. Epidemiology (continued) Usually occurs in people between 5 and 18 years old.
Males and females equally affected.
Overcrowding, poverty, lack of access to medical care contributes to transmission.
Virulence of strain important.
6. Pathogenesis Group A strep pharyngeal infection precedes clinical
manifestations of ARF by 2 - 6 weeks.
Antibodies made against group A strep cross-react with human tissue:
heart valve and brain share common antigenic sequences.
with GAS bacteria.
theory of molecular mimicry
Host immune responses may play a role in determining who gets ARF following infection.
Virulent strains: rheumatogenic serotypes.
7. Clinical Features Following upper airway infection with GAS:
Silent period of 2 - 6 weeks.
Sudden onset of fever, pallor, malaise, fatigue.
8. Clinical Features (continued) Characterized by:
Arthritis.
Carditis.
Sydenham’s chorea.
Erythema marginatum.
Subcutaneous nodules.
Called “major manifestations” of Jones criteria either because of frequency or specificity.
9. Clinical Features (continued) Other features:
Arthralgias.
Epistaxis.
Serositis.
Involvement of lung, kidneys and CNS.
11. Carditis Most serious manifestation.
May lead to death in acute phase or at later stage.
Any cardiac tissue may be affected (pancarditis):
Valvular lesion most common: mitral and aortic.
Seldom see isolated pericarditis or myocarditis.
Acute phase: Aschoff bodies at any layer of the heart
Fibrinous or serofibrinous pericarditis (bread and butter ) -----No sequlae
Myocardium : Ascoff bodies
Valve: fibrinoid necrosis within the cusps or tendon
12. Subcutaneous Nodules Usually 0.5 - 2 cm long:
Firm, non-tender, isolated or in clusters.
Most common:
along extensor surfaces of joint Knees, elbows, wrists
Also: on bony prominences, tendons, dorsi of feet,
occiput or cervical spine.
Last a few days only.
Occur in 9 - 20% of cases.
Often associated with carditis.
13. Erythema Marginatum Present in 7% of patients.
Highly specific to ARF.
Cutaneous lesion:
Reddish pink border.
Pale center.
Round or irregular shape.
Often on trunk, abdomen, inner arms, or thighs.
Highly suggestive of carditis.
15. Diagnois Jones criteria:
Criteria developed to prevent overdiagnosis.
Some criticism regarding validity.
Still important as guidelines.
Probability of ARF high with:
Evidence of previous infection with streptococcal upper.
airway infection and:
2 major criteria.
or
1 major criteria and 2 minor criteria.
16. Diagnosis: Jones Criteria Major criteria:
Arthritis.
Carditis.
Sydenham’s chorea.
Erythema marginatum.
Subcutaneous nodues.
17. Diagnosis: Jones Criteria (continued) Minor manifestations:
Fever.
Arthralgia.
Elevated c-reactive protein.
or
Erythrocyte sedimentation rate.
Prolonged PR interval on EKG.
18. Diagnosis: Evidence of Previous Infection Culture.
Antisteptolysin-O antibody:
Often elevated in healthy children or with Rheumatoid
Arthritis, Henoch-Schonlein Purpura, Takayasu’s
Arteritis.
Antibodies to other strep antigens:
Anti-DNAase B, anti-hyaluronidase, anti-streptokinase,
anti-nicotinamide.
19. Treatment Eradication of the group A strep most important:
Avoids chronic exposure of immune system to strep.
Best: single dose IM benzathine penicillin G.
20. Mitral Stenosis Rheumatic Valvular Heart Disease
Rheumatic heart disease causes mitral stenosis in 99.8% of cases.
21. Acute Rheumatic Valvulitis Pathophysiology
Multiple
episodes of
Acute
Rheumatic
Fever (ARF)
First?
pancarditis
22. Acute Rheumatic Valvulitis Pathophysiology Acute phase subsides:
Fibrosis alters leaflet and cusp structure.
Results in leaflet or cuspal thickening along valvular margins of closure.
Valves affected:
Most often mitral valve alone.
Then mitral and aortic together.
Aortic alone.
Tricusped
23.
Normal mitral valve:
Fusion of chordae .
Stenotic mitral valve:
Thickening of cusps.
24. Effects of Mitral Stenosis
On heart.
On lungs.
On right ventricle.
25. Effect of Mitral Stenosis On Heart
Left atrium :Hypertrophies and dilates 2° ?pressure.
Atrial fibrillation and mural thrombosis follow.
Left ventricleis: “protected” by stenotic mitral valve.
LV usually normal in size and contour.
26. Effect of Mitral Stenosis On Heart Pulmonary arterial pressure ?:
Intimal and medial hypertrophy of pulmonary arteries ?pulmonary vascular resistance.
Right ventricle :dilates from pressure overload.
Main pulmonary artery dilates pulmonary valve regurgitation.
27. Effect of Mitral Stenosis On Heart
Tricuspid regurgitation develops:
2° dilated RV.
Right atrium: dilates 2° volume overload.
Right heart failure.
28. Aortic Regurgitation (Aortic Insufficiency)
29. Aortic Regurgitation Rheumatic Heart Disease
Thickened cusps.
May have commissural fusion:
In degenerative Ao regurg, no commissural fusion.
Regurgitant jet is usually central:
In degenerative, usually not discrete jet.
30. Cardiac neoplasm Benign :
Myxoma.
Fibroma
Rhabdomyoma.
Malignant:
Rhabdomyosarcoma.
Angiosarcoma.
Metastasis.
31. This two year old child died suddenly. At autopsy, a large firm, white tumor mass was found filling much of the left ventricle. This is a cardiac rhabdomyoma. Such primary tumors of the heart are rare.
