Rheumatic Disease Heart Effect
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IMENE BENAYACHE.MD
SINOE MEDICAL ASSCIATION
Rheumatic fever, MS and AoR.
Part I:
I/. Introduction:
Ø RF is an hypersensitivity reaction occuring 2-3 weeks after beta-hemolytic A streptococcal infection (pharyngitis).
Ø Primary seen in children ages 5-15 year-old, and occurrence in the adulthood.
II/. Pathogenesis:
Ø HLA relationship (familial occurrence).
Ø Toxic products of streptococci.
Ø Host develops antibodies against M protein of strep, which has cross-reactivity against the heart.
Ø Antibodies set up immune response against other tissues (joints, skin, basal ganglia).
Ø Sensitized-T-lymphocytes may mediate cardiac injury.
Ø It is not a streptococcal septicemia.
Ø Familail occurrence, crowding.
Ø Seasonal prevalence of RF and strep.pharyngitis are parallel in winter.
Ø Anti-streptolysin O titer rises during rheumatic fever attack.
Ø Patients with previous attacks of RF are at great risk for recurrences and further damage to cardiac valves.
III/. The pathogen agent:
Ø A gram positive cocci “group A beta-hemolytic streptococcus”.
Ø It is composed of a core cytoplasmic surrounded by a cytoplasmic membrane and a cell wall, which is surrounded by a capsule.
Ø The capsule is composed of hyaluronidase, which is nonantigenic.
Ø Cell wall is composed of three layers:
· External a protein layer
· Middle carbohydrate layer
· Internal mucopeptide protoplast layer.
Ø The protein layer contains the proteins designated M, T and R. The M protein is the most important because it determines the virulence of the organism, stimulates formations of opsonizing and precipitating antibodies, and may impede phagocytosis.
Ø Lancefield classified group A streptococcus into serologic types on the basis of the M protein.
Ø Acute Rheumatic fever results from infection by group A beta hemolytic streptococci
Auto-antibodies produced against the M protein antigen.
Ø The middle layer of the cell wall, the carbohydrate layer, provides the group specification of the streptococcus.
Ø N-Acetylglucosamine is the group specific carbohydrate, for group A streptococci.
Ø The streptococcus produces a number of extracellular products.
· Streptolysin-O is cardiotoxic and leukotoxic and is responsible for hemolysis of erythrocytes. Streptolysin-O will elicit an antibody response, antistreptolysin-O, in 70%-85% of infected persons, and this form the basis of useful assay of invasive streptococcal infection.
Ø Early and effective antibiotic treatment of streptococcal infections can suppress this antibody response.
Ø Extracellular proteinase can cause myocardial necrosis.
Ø Streptokinase activates plasma proteins and converts plasminogen to plasmin.
Ø Diphosphopyridine nucleotide nucleotidase) in 87% of patients with acute rheumatic fever.
Ø It is useful to adjunct to the antistreptolysin-O titer in identifying patients with invasive streptoccocal disease.
Ø There are 4 deoxyribonucleases (A, B, C, and D), all are antigenic.
· Deoxyribonuclease B is produced in the largest quantities in response to group A streptoccocal infection.
· Antideoxyribonuclease antibodies are useful indicators of invasive streptococcal disease.
V/. Clinical diagnosis:
Ø Are based on Jones criteria.
Ø Jone`s stipulates that we need either 2 major or 1 major and 2 minor criteria to make the diagnostic.
“Jones Criteria.”
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Major Criteria.
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Minor Criteria.
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Ø Arthritis (migratory polyarthritis, swollen, red, tender).
Ø Carditis (friction rub, murmur, cardiomegaly, CHF, ECG changes).
Ø Sydenham`s chorea (jerky, purposeless movements that can occur months later, usually resolves).
Ø Subcutaneous nodule (< 2 cm, firm, attached to fascia or tendon sheaths on dorsal surfaces of hands, vertebral, etc..
Ø Erythema marginatum.
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Ø Clinical:
· Fever
· Arthralgia
· History of rheumatic fever.
Ø Laboratory:
· Acute phase reactants (ESR, C-reactive protein, leukocytosis).
· Prolonged PR interval on ECG.
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VII/. Para-clinic diagnosis:
Ø Throat culture (strep) (gold standard for diagnosis).
Ø Nonspecific evidence of inflammatory disease:
· CBC
· Sedimentation rate
Ø Evidence of antecedent beta-hemolytic strep infection:
· ASO
· CRP
Ø If cardiac involvement:
· ECG ® prolonged PR.
· CXR ® may be normal or cardiomegaly.
· Echocardiogram ® if pericardial effusion.
VIII/.Treatement.
A. Treatment of rheumatic fever.
“Antibiotic”.
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“Dose”.
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“Mode”.
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Benzathine Penicillin G:
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Ø 600,000 U for patients £ 27 kg.
Ø 1,2000,000 U for patients > 27 kg.
Ø A single dose.
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Ø IM.
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Penicillin V (phenoxymethyl peni):
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Ø Children: 250 mg 2-3 times daily for 10 days.
Ø Adolescents and adults: 500 mg 2-3 times daily for 10 days.
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Ø Oral.
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Erythromycin: if allergy to peni
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Ø Children: 40 mg/kg/day 2-4 times a day (max 1g/d) for 10 days.
Ø Adult: 250 mg qid for 10 days.
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Ø Oral.
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Clindamycin:
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Ø Children: 40 mg/kg/day for 10 days (tid).
Ø Adult: 300 mg tid for 10 days.
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Ø Oral.
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B. Prophylaxis.
“Antibiotic”.
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“Dose”.
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“Mode”.
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Benzathine Penicillin G:
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Ø 1,200,000U every 4 weeks or 3 weeks for high-risk patient such as those with residual carditis.
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Ø IM.
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Penicillin V:
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Ø 250 mg twice daily.
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Ø Oral.
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Erythromycin:
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Ø 250 mg twice daily.
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Ø Oral.
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Ø In patient with known or suspected rheumatic valve disease prophylaxis against bacterial endocarditis should be instituted for:
· Dental or oral surgical procedures.· Surgery of URT or GU or GI.
Ø Prophylaxis is indicated because he has different episodes and he will develop other.
Ø The severity of complications increases with each infection.
Ø The debilitating sequel in the adulthood.
IX/. Complications of RF:
Ø Mostly cardiac, all the layers of the heart can be concerned including:
· Endocardium (endocarditis).
· Myocardium (myocarditis).
· Pericardium (pericarditis).
Ø Endocarditis:
· In acute rheumatic fever (ARF), mitral regurgitation is the finding.
· In chronic rheumatic fever (CRF), mitral stenosis is the finding.
· 48% mitral alone involved and 42% mitral and aortic is involved.
· Mitral > aortic > tricuspid > pulmonic.
Ø Acute myocarditis is the MCC of death in ARF.
Ø Pericarditis (fibrinous) is seen in ARF.
Ø CHF is the MCC of death from chronic valvular disease of CRF.
XI/. ARF VS CRF:
Part II:
I/. Definition:
Ø Obstruction of blood flow from LA to LV because of narrowed mitral orfice.
Ø The valve has difficulty opening.
II/. Etiology:
Ø Congenital MS: in kids rarely live beyond 2 years, unless it is supravalvular. (Rare cause of MS).
Ø Acquired:
· CRF
· Systemic lupus erythematous (SLE).
· Malignant carcinoids
· Gout.
· Whipple`s disease.
· Mucopolysaccharidosis.
· Rheumatoid arthritis (RA).
· Atrial myxoma.
· Bacterial endocarditis.
III/. Pathophysiology:
Ø Pure MS develops in 40% of all patients with RF.
Ø MC valve deformity in CRF.
Ø Latency period is 10-20 years between an episode of RF and the onset of symptoms.
Ø Mitral valve orifice is 4-6 cm2. When this orifice is reduced to 2cm2 Þ LA pressure is necessary for flow of blood from atria to ventricle.
Ø When valve orifice is £ 1cm2 Þ critical symptoms of MS occurs.
Ø Obstruction of flow of LA to LV ® ¯ diastolic filling of LV and ¯ the 1st CO Þ fatigue.
Ø in LAP Þ pulmonary venous and capillary pressures Þ exertional dyspnea.
Ø Chronic of LAP Þ pulmonary hypertension Þ TR and PR and eventual Þ RHF.
Ø LHF is not a feature of early disease.
Ø LAP Þ dilatation of LA, which predispose to 2 dangerous complications:
· Formation of mural thrombi because of LAE, which embolizes in 20% of patients.
· Atrial fibrillation in 40% of patients, which is the MC cardiac arrhythmia associated with thromboembolism (acts like a vibrator, which dislodges pieces of clots material).
· Those 2 are closely related.
Ø Female > male.
Ø Age: between the 3rd and 4th decades.
IV/. Clinical manifestation:
A. Symptoms or functional signs:
Ø The 1st symptoms are:
· Exertional dyspnea.
· Fatigue.
· Orthopnea progressing to paroxysmal noctural dyspnea.
Ø Later in the course of the disease:
· Recumbent cough
· Hemoptysis due to rupture of small pulmonary vessels.
· Pink or blood-tinged sputum that occurs with pulmonary edema.
· Palpitations
· Left vocal cord paralysis (Ortner`s syndrome) due to paralysis of left recurrent laryngeal nerve, which is compressed when a dilated LA presses it against a dilated pulmonary artery.
B .Physical signs:
Ø Peripheral cyanosis.
Ø Plum-colored malar flush (mitral facies), seen in low CO and severe pulmonary hypertension.
Ø JVD with positive hepatojugular reflex.
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Ø Occur mostly in children.
Ø Occur mostly in adult.