Acute rheumatic fever

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Acute rheumatic fever

  1. 1. Dr. Sharan . S. D
  2. 2.  Acute rheumatic fever is a multisystem disease resulting from an autoimmune reaction to infection with group A streptococcus. Although many parts of the body may be affected, almost all of the manifestations resolve completely. The exception is cardiac valvular damage [rheumatic heart disease (RHD)], which may persist after the other features have disappeared
  3. 3.  ARF is mainly a disease of children aged 5–15 years. Initial episodes become less common in older adolescents and young adults and are rare in persons aged >30 years. By contrast, recurrent episodes of ARF remain relatively common in adolescents and young adults. This pattern contrasts with the prevalence of RHD, which peaks between 25 and 40 years. There is no clear gender association for ARF, but RHD more commonly affects females, sometimes up to twice as frequently as males.
  4. 4.  ARF is exclusively caused by infection of the upper respiratory tract with group A streptococci. Although classically, certain M-serotypes (particularly types 1, 3, 5, 6, 14, 18, 19, 24, 27, and 29) were associated with ARF, in high-incidence regions. It is now thought that any strain of group A streptococcus has the potential to cause ARF. Potential role of skin infection and of groups C and G streptococci are currently being investigated.
  5. 5.  Approximately 3–6% of any population may be susceptible to ARF, and this proportion does not vary dramatically between populations. Findings of familial clustering of cases and concordance in monozygotic twins— particularly for chorea—confirm that susceptibility to ARF is an inherited characteristic.
  6. 6.  Particular human leukocyte antigen (HLA) class II alleles appear to be strongly associated with susceptibility. Associations have also been described with high levels of circulating mannose-binding lectin and polymorphisms of transforming growth factor 1 gene and immunoglobulin genes
  7. 7.  High-level expression of a particular alloantigen present on B cells, D8-17, has been found in patients with a history of ARF in many populations, with intermediate-level expression in first-degree family members-- marker of inherited susceptibility.
  8. 8.  When a susceptible host encounters a group A streptococcus, an autoimmune reaction results, which leads to damage to human tissues as a result of cross-reactivity between epitopes on the organism and the host
  9. 9.  Cross-reactive epitopes are present in the streptococcal M protein (M1,M5,M6,M19)and the N- acetylglucosamine of group A streptococcal carbohydrate and are immunologically similar to molecules in human myosin, tropomyosin, keratin, actin, laminin, vimentin, and N-acetylglucosamine. It is currently thought that the initial damage is due to cross-reactive antibodies attaching at the cardiac valve endothelium, allowing the entry of primed CD4+ T cells, leading to subsequent T cell-mediated inflammation
  10. 10.  There is a latent period of 3 weeks (1–5 weeks) between the precipitating group A streptococcal infection and the appearance of the clinical features of ARF … The exceptions are indolent carditis and chorea, which may follow prolonged latent periods lasting up to 6 months … A prior sore throat, the preceding group A streptococcal infection is commonly subclinical; in these cases it can only be confirmed using streptococcal antibody testing … The most common clinical presentation of ARF is polyarthritis and fever…
  11. 11.  Polyarthritis is present in 60–75% of cases and carditis in 50–60% … The prevalence of chorea in ARF varies substantially between populations, ranging from 10-15%… Erythema marginatum and subcutaneous nodules are now rare, being found in <5% of cases …
  12. 12.  Up to 60% of patients with ARF progress to RHD … The endocardium, pericardium, or myocardium may be affected. Valvular damage is the hallmark of rheumatic carditis … The mitral valve is almost always affected, sometimes together with the aortic valve; isolated aortic valve involvement is rare … Early valvular damage leads to regurgitation. Over ensuing years, usually as a result of recurrent episodes, leaflet thickening, scarring, calcification, and valvular stenosis may develop …
  13. 13.  Acute rheumatic carditis usually presents as tachycardia & cardiac murmur,with or without evidence of myocardial or pericardial involvment… Moderate to severe rheumatic carditis can results in cardiomegaly or CCF with hepatomegaly ,peripheral &pulmonary edema… ECHO findings includes pericardial effusion,decreased ventricular contractility & aortic or mitral regurgitation…
  14. 14.  Therefore the characteristic manifestation of carditis in previously unaffected individuals is mitral regurgitation, sometimes accompanied by aortic regurgitation … Myocardial inflammation may affect electrical conduction pathways, leading to P-R interval prolongation (first-degree AV block or rarely higher-level block) and softening of the first heart sound …
  15. 15.  To qualify as a major manifestation, joint involvement in ARF must be arthritic, i.e., objective evidence of inflammation with hot, swollen, red and/or tender joints, and involvement of more than one joint (i.e., polyarthritis) …*The typical arthritis is migratory, moving from one joint to another over a period of hours …ARF almost always affects the large joints—most commonly the knees, ankles,wrist,and elbows—and is asymmetric. The pain is severe and usually disabling until anti-inflammatory medication is commenced …
  16. 16.  Involvement of spine small joints of hand & feet or hips is uncommon… The joint involvment is characteristically migratory in nature,severly inflammed joint can become normal within 1-3days without treatment,as 1 or more other large joints become involved… Monoarticular arthritis is unusual unless anti- inflammatory theraphy is initiated…
  17. 17.  joint involvement that persists more than 1 or 2 days after starting salicylates is unlikely to be due to ARF … Conversely, if salicylates are commenced early in the illness, before fever and migratory polyarthritis have become manifest, it may be difficult to make a diagnosis of ARF … For this reason, salicylates and other NSAIDs should be withheld—and pain managed with acetaminophen or codeine—until the diagnosis is confirmed …
  18. 18.  Occurs in about 10-15% of patient with ARF… Sydenhams chorea commonly occurs in the absence of other manifestations, follows a prolonged latent period after group A streptococcal infection, and is found mainly in females … The choreiform movements affect particularly the head (causing characteristic darting movements of the tongue) and the upper limbs … They may be generalized or restricted to one side of the body (hemi-chorea) …
  19. 19.  The chorea varies in severity … In mild cases it may be evident only on careful examination, while in the most severe cases the affected individuals are unable to perform activities of daily living and are at risk of injuring themselves… Chorea eventually resolves completely, usually within 6 weeks…
  20. 20.  Clinical maneuvers to elicit features of chorea include (1) demonstration of milkmaids grip (irregular contractions of the muscles of the hands while squeezing the examiners fingers). (2) spooning and pronation of the hands when the patients arms are extended. (3) wormian darting movements of the tongue upon protrusion. (4) examination of handwriting to evaluate fine motor movements.
  21. 21.  Usually presents as an isolated, frequently subtle, neurologic behavior disorder. Emotional lability, incoordination, poor school performance, uncontrollable movements, and facial grimacing, exacerbated by stress and disappearing with sleep, are characteristic.
  22. 22.  The classic rash of ARF is erythema marginatum which begins as pink macules that clear centrally, leaving a serpiginous, spreading edge. It occurs usually on the trunk, sometimes on the limbs, but almost never on the face.
  23. 23.  Rare < 3% of patients with ARF but characteristic rash of ARF… It consist of erythematous,serpiginous,macular lesions with pale centre that are not pruritic… It occur primarily on the trunk & extremities,but not on the face & can be accentuated by warming the skin…
  24. 24. Subcutaneous nodules occur as painless, small (0.5– 2 cm), mobile lumps beneath the skin overlying bony prominences, particularly of the hands, feet, elbows, occiput, and occasionally the vertebrae …*Rare less 1% of patients with ARF.* MC along extensor surface of tendon near bony prominences…
  25. 25.  They are a delayed manifestation, appearing 2–3 weeks after the onset of disease, last for just a few days up to 3 weeks, and are commonly associated with carditis …
  26. 26.  Arthralgia in the absence of polyarthritis… Fever typically temp >102*F… The two LAB minor criteria are elevated acute phase reactants ( CRP,ESR ) and prolonged PR interval on ECG (1st degree heart block)
  27. 27.  With the exception of chorea and low-grade carditis, both of which may become manifest many months later, evidence of a preceding group A streptococcal infection is essential in making the diagnosis of ARF. As most cases do not have a positive throat swab culture or rapid antigen test, serologic evidence is usually needed.
  28. 28.  The most common serologic tests are the anti- streptolysin O (ASO) and anti-DNase B (ADB) titers. Where possible, age-specific reference ranges should be determined in a local population of healthy people without a recent group A streptococcal infection.
  29. 29.  All patients with acute rheumatic fever should be placed on bed rest & monitored for evidence of carditis… Patients with carditis requires longer periods of bed rest…
  30. 30.  Once a diagnosis of ARF has been established & regardless of throat culture results,the patient should receive 10 days of orally administered penicillin or erythromycin or single intramuscular injection of benzathine penicillin to eradicate GAS from upper respiratory tract… After this initial course of antibiotic therapy,the patient should be started on long term antibiotics prophylaxis…
  31. 31.  Anti-inflammatory agents(eg:salicylates,corticosteroids) should be withheld if arthralgia or atypical arthritis is only clinical manifestation of presumed ARF… Early treatment with one of these agents may interfere with development of characteristic migratory polyarthritis & thus obscure the diagnosis of ARF…
  32. 32.  Agents such as acetaminophen can be used to control pain & fever while the patient is being observed for more definative signs of ARF & for evidence of another disease…
  33. 33.  Patients with typical migratory polyarthritis & those with carditis without cardiomegaly or CCF should be treated with oral salicylates… Usual dose of aspirin is 100 mg/kg/day in 4 divided doses PO for 3-5 days ,followed by 75mg/kg/day in 4 divided doses PO for 4 weeks
  34. 34.  Patients with carditis & cardiomegaly or CCF should receive corticosteroids… Usual dose in 2mg/kg/day in 4 divided doses for 2-3 week f/b tapering dose of 5mg/day for every 2-3 days… Aspirin should be at 75mg/kg/day in 4 divided doses for 6 weeks
  35. 35.  Supportive therapies for patients with moderate to severe carditis includes digoxin,fluid and salt restriction,diuretics and oxygen… Cardiac toxicity of digoxin is enhanced with myocarditis
  36. 36.  Sedative may be helpful early in course of chorea : Phenobarbital (16-32 mg every 6-8 hr PO) is drug of choice… If phenobarbital is ineffective,then haloperidol(0.001-0.003mg/kg/24hrs divided bid PO ) or chlorpromazine (0.5mg/kg every 4- 6 hr PO ) should be started…
  37. 37.  Prognosis for patients with ARF depends on initial clinical manifestation present at time of initial episodes,severity of initial episodes,presence or recurrence… Approximately 70% of patients with carditis during initial episodes of ARF recover with no residual heart disease… More severe the initial episodes are greater risk is for residual heart disease
  38. 38.  Patients who had ARF are susceptible to recurrent attacks following reinfection of upper respiratory with grp A streptococcus.Therefore patients require long-term continous prophylaxis…. Approximately 20% of patients who presents with pure chorea who are not given secondary prophylaxis develop RHD within 20 years…
  39. 39.  Approximately antibiotic theraphy instituted before the 9th day of symptoms of acute grp A streptococcus pharyngitis is highly effective in preventing 1st attack of ARF from that episode… About 30 % of patients with ARF don’t recall a preceeding episodes of pharyngits…
  40. 40.  Valvular lesions in rheumatic fever begins as small verrucae composed of fibrin & blood cells along the borders of one or more of the heart valves… Mitral valve is affected most often,f/b aortic valve;right sided heart manifestations are rare…
  41. 41.  As the inflammation subsides verrucae tend to disappear & leave scar tissue… With repeated attacks of rheumatic fever,new verrucae form near the previous ones,and the mural endocardium & chordae tendineae becomes involved…
  42. 42.  PATHOPHYSIOLOGY : Mitral insufficiency is result of structural changes that usually include some loss of valvular substance & shortening & thickening of chordea tendineae…
  43. 43.  During acute rheumatic fever with severe cardiac involvement,heart failure is caused by a combination of mitral insufficiency coupled with inflammatory disease of preicardium,myocardium,endocardium & epicardium… Because of high volume load & inflammatory process,the left ventricle becomes enlarged… The left atrium dilated as blood regurgitates into this chamber…
  44. 44.  Increased left atrial pressure results in pulmonary congestion & symptoms of left heart failure… More than half of patients with acute mitral insufficiency no longer have the mitral murmur at 1 year… Severe chronic mitral insufficiency,pulmonary arterial pressure becomes elevated,the right ventricle & atrium become enlarged, & right-sided heart failure subsequently develops …
  45. 45.  In mild disease,signs of heart failure are not persent,the precordium is quiet,a high pitched holosystolic murmur at apex that radiates to axilla… Severe mitral insufficiency ,signs of chronic heart failure may be noted,cardiomegaly with a heaving apical left ventricular impulse & often an apical systolic thrill…
  46. 46.  2nd HS may be accentuated if pulmonary HTN in present… Holosystolic murmur is heard at the apex with radiation to axilla… A short mid-diastolic rumbling murmur is caused by increased blood flow across mitral valve d/t insufficiency…
  47. 47.  Presence of diastolic murmur doesn’t necessarily mean that mitral stenosis is present… It take many years to develop MS & is characterised by a diastolic murmur of greater length,usually with presystolic accentuation…
  48. 48.  ECG,CXR is normal if lesion is mild… More severe insufficiency,the ECG show prominent bifid P waves,signs of LVH,& associated RVH if pulmonary HTN is present… CXR : prominence of left atrium & ventricle,congestion of perihilar vessels,a sign of pulmonary venous HTN may be evident…
  49. 49.  Calcification of mitral valve is rare in children… ECHO shows enlargment of left atrium & ventricle,an abnormally thickened mitral valve,DOPPLER demonstrate the severity of MR… Heart catheterization & left ventriculography…
  50. 50.  Severe mitral insufficiency may result in cardiac failure that may be precipitated by progression of rheumatic process,onset of AF,or infective endocarditis… Effect of chronic MR may manifest after many years & include RVF, atrial & ventricular arrhythmias …
  51. 51.  In mild MR prophylaxis against recurrences of rheumatic fever is all that is required… Afterload-reducing agents(ACE inhibitors or angiotensin receptor blocker ) may reduce the reguritant volume & preserve left ventricular function…
  52. 52.  Treat underlying heart failure,arrhythmias,infective endocarditis… Surgical treatment is indicated for patients who despite adequate medical theraphy have persistent heart failure,dyspnea with moderate activity,and progressive cardiomegaly,often with pulmonary HTN…
  53. 53.  In patients with a prosthetic mitral valve replacement,prophylaxis against bacterial endocarditis is warranted for dental procedure,as routine antiobiotics taken by these patients for rheumatic fever prophylaxis are insufficient to prevent endocarditis …
  54. 54.  PATHOPHYSIOLOGY : Mitral stenosis of rheumatic origin results from fibrosis of mitral ring,commissural adhesion,contracture of valve leaflets,chordae & papillary muscle over time…Its take 10 years or more for lesion to become fully established….
  55. 55.  Significant mitral stenosis results in increased pressure , enlargement & hypertrophy of left atrium,pulmonary venous HTN,increase pulmonary vascular resistance,pulmonary HTN… RVH,RAD ensue & are followed by RVD,TR & clinical sign of right-sided heart failure…
  56. 56.  Mild lesion are symptomatic … More severe degree of obstruction are associated with exercise intolerance & dyspnea… Critical lesions can result in ortopnea,PND,overt pulmonary edema,atrial arrhythmias…
  57. 57.  When pulmonary HTN has developed,right ventricular dilatation may result in functional TR,hepatomegaly,ascites & edema… Hemoptysis caused by rupture of bronchial or pleurohilar veins & occasionally pulmonary infarction may occur…
  58. 58.  Jugular venous pressure is increased in severe disease with heart failure,tricuspid valve disease,or severe pulmonary HTN… In mild cases,heart size is normal,in moderate cardiomegaly is usual with severe MS… Cardiac enlargement can be massive when AF & HF supervene …
  59. 59.  A parasternal RV lift is palpable when pulmonary pressure in high… A loud 1st HS , opening snap of mitral valve,& long,low-pitched,rumbling mitral diastolic murmur with presystolic accentuation at the apex …
  60. 60.  Mitral diastolic murmur may be virtually absent in patient who are in significant HF… A holosystolic murmur secondary to TR may be audible.. In presence of pulmonary HTN,pulmonary component of 2nd HS is accentuated… Early diastolic murmur may be caused by associated AR or PR secondary to pulmonary HTN
  61. 61.  In severe cases prominent & notched P waves & varying degrees of RVH become evident… AF is common late manifestation… Moderate or severe lesion CXR : signs of LA enlargment & prominence of PA & right sided chambers,calcification may be noted in mitral valve …
  62. 62. • Doppler can estimate the transmitral pressure gradient…• ECHO : thickening of mitral valve,distinct narrowing of mitral orifice during diastole & LA enlargment…• Cardiac catheterisation quantitates the diastolic gradient across the mitral valve,degree of elevation of PA pressure…
  63. 63.  Ballon valvuloplasty is indicated for symptomatic,stenotic,pliable,noncalcified valves of patients without atrial arrhythmias or thrombi…
  64. 64.  AR leads to volume overload with dilatation and hypertrophy of the LV… Combined MR & AR is more common than aortic involvment alone…
  65. 65.  Symptoms are unusual except in severe AR… Large stroke volume & forceful left ventricular contraction may result in palpitations… Sweating & heat intolerance are related to excessive vasodilation… Dysnea on exertion can progress to orthopnea & pulmonary edema,angina may be precipitated by heavy exercise… Nocturnal attacks with sweating,tachycardia,chest pain and HTN may occur…
  66. 66.  Pulse pressure is wide with bounding peripheral pulses… SBP is elevated,Diastolic BP is lowered… In severe AR ,heart is enlarged with a LV apical heave… A diastolic thrill may be present… Typical murmur begins immediately with 2nd HS & continues until late in diastole…
  67. 67.  Murmur best heard at upper & midleft sternal border with radiation to apex & upper right sternal border… A aortic systolic ejection murmur is frequent because of increased stroke volume… An apical presystolic murmur(Austin flint murmur) resembling that of MS …
  68. 68.  ECG : Signs of LVH & strain with prominent P waves… ECHO : large LV & diastolic mitral valve flutter or oscillation caused by regurgitant flow hitting the valve leaflets… DOPPLER : degree of aortic runoff into LV… MRA

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