Presentation on theme: "Frequency Leading cause of death and common cause of structural heart damage until 1960 US has experienced a resurgence of RF in the last two decades."— Presentation transcript:
1 FrequencyLeading cause of death and common cause of structural heart damage until 1960US has experienced a resurgence of RF in the last two decades. Why? Possibly more virulent strains of Group A streptococci.ARF problem in high-risk areas of the tropics, countries with limited resources and where there is minority indigenous populationsCardiac involvement = major cause of long-term morbidityMost cases = 5-15 years oldPenicillin Jones Criteria
2 2 Patterns of Presentation Sudden onset = typically begins as polyarthritis 2-6 weeks after streptococcal pharyngitisFeverToxicityInsidious (subclinical) = initial abnormality is mild carditisAge at onset influences complication order: younger children = carditis, older = arthritis
3 Modified Jones Criteria Diagnosis requires:High index of clinical suspicionEvidence of previous strep infection2 major Jones criteriaOR1 major + 2 minor Jones criteria
4 Major criteria Carditis: cardiomegaly, new murmur, CHF, pericarditis Migratory polyarthritis: fleeting, large jtsSubcutaneous nodules: firm and painless along extensor surfaces of the wrist, elbow and kneeErythema marginatum: serpiginous rashChorea (“St Vitus dance”): rapid, purposeless movements of the face and upper extremities
5 Minor criteria Clinical: arthralgia, fever and previous history of ARF Laboratory: ^ESR/CRP, prolonged PR interval, supporting evidence of antecedent group A strep infection (+ throat culture, + rapid strep screen, ^strep antibody titer)
6 Lab Studies None to specifically diagnose Strep antibody tests discloses preceding strep infectionIsolate group A strep in throat cultureAcute phase reactions: ESR, CRP, ^ seum complement, mucoproteins, alpha-2, and gamma globulinsProlonged PR intervalTroponins: not helpful since ischemia and necrosis are not the cause of cardiac probles
7 NewerRapid detection test for D8/17: This immunofluorescence technique for identifying the B cell marker D8/17 is positive in 90% of patients with rheumatic fever. It may be useful for identifying patients who are at risk for developing rheumatic fever.
8 Radiographic StudiesEchocardiography: helpful in establishing carditisSynovial fluid: may demonstrate ^ WBCs
9 Prevention Treat all GABHS pharyngitis with antibiotics Confirm infection with:Rapid strep followed by culture in children and adolescentsRapid strep in adults
10 Teatment Steroids, ASA and Naproxen for pain and inflammation Digitalis for heart failureHaloperidol for choreaConsultations to cardiologist, rheumatologist and neurologistProphylaxis for ARF pts x 5 yrs to prevent future infections (benzathine penicillin G 1.2 million U IM q month, pen V 250mg PO bid, erythromycin 250 mg PO bid)
12 Rheumatic Heart Disease Chronic rheumatic heart disease is the leading cause of mitral valve stenosis and valve replacement in the U.S.Produces a pancarditisprotein is the most important virulence factor for group A streptococcal infection in humans. More than 90 M serotypes have been identified, some of which have a long terminal antigenic domain (epitopes) similar to antigens in various components of the human heart. Rheumatogenic strains often are encapsulated mucoid strains rich in M proteins and resistant to phagocytosis. These strains are strongly immunogenic, and anti–M antibodies against the streptococcal infection may cross react with heart tissue.
13 Cardiac InvolvementCharacterized by endocarditis, pericarditis and myocarditisEndocarditis manifested as valve insufficiency: mitral 60-75% of the timeAortic valve 25% of the timeTricuspid 10% of the time9-39% adults with previous RF have residual progressive valve disease
14 Cardiac MorbidityFusion of valve apparatus occurs 2-10 years status post infectionRHD responsible for 99% of mitral valve adult disease in the U.S.May have associated atrial fibrillation and or left atrial thrombus formationPrognosis worse for females
15 Cardiac Manifestations Pancarditis = most serious & second most common complication (50%). Advanced cases c/o dyspnea, mild-to-mod chest discomfort, pleuritic chest pain, edema, cough, orthopneaPE = carditis detected by new murmur & tachycardia out of proportion to fever. New/ changing murmurs needed to dx R valvulitis.CHF and pericarditis.Patients with acute RF should be examined frequently
16 Valvular Insuff MM of RF Apical pansystolic mm: high-pitched, blowing-quality of mitral regurg radiating to left axilla. Unaffected by respiration or position. >Grade 2/6 .Apical diastolic mm ( Carey-Coombs ) heard with active carditis and accompanies severe mitral insufficiency. Bell of stethoscope, with patient in left lateral position and breath held in expiration. Low pitched, rumbling, & resembles distant drum.Basal diastolic mm early mm of aortic regurg: high-pitched, blowing, decrescendo, heard best along right upper sternal border after deep expiration with pt leaning forward.
17 Complications of RF MM Congestive heart failure Heart failure may develop secondary to severe valve insufficiency or myocarditis.The physical findings associated with heart failure include tachypnea, orthopnea, jugular venous distention, rales, hepatomegaly, a gallop rhythm, and peripheral swelling and edema.
18 More Complications Pericarditis A pericardial friction rub Increased cardiac dullness to percussion and muffled heart sounds consistent with pericardial effusion.A paradoxical pulse (drop in systolic blood pressure with inspiration) with decreased systemic pressure and perfusion and evidence of diastolic indentation of the right ventricle on echocardiogram reflect impending pericardial tamponade. In this clinical emergency, pericardial effusion should be treated by pericardiocentesis.
19 Valve DeformitiesMitral stenosis in 25% of patients with CRHD and in association with mitral insufficiency in another 40%. Progressive fibrosis results in enlargement of left atrium and formation of mural thrombi. The stenotic valve is funnel-shaped, with a "fish mouth" resemblance. On auscultation, S1 is initially accentuated but becomes reduced as the leaflets thicken. P2 becomes accentuated, and the splitting of S2 decreases as pulmonary hypertension develops. An opening snap of the mitral valve often is heard at the apex, where a diastolic filling murmur also is heard.Aortic stenosis from chronic rheumatic heart disease typically is associated with aortic insufficiency. The valve commissures and cusps become adherent and fused, and the valve orifice becomes small with a round or triangular shape. On auscultation, S2 may be single because the aortic leaflets are immobile and do not produce an aortic closure sound. The systolic and diastolic murmurs of aortic valve stenosis and insufficiency are heard best at the base of the heart.Thromboembolism occurs as complication of mitral stenosis. It is more likely to occur when the left atrium is dilated, cardiac output is decreased, and the patient is in atrial fibrillation. The frequency of this complication is decreased with use of anticoagulation and surgical repair of valve abnormalities.
20 Other ComplictionsCardiac hemolytic anemia related to disruption of RBCs by deformed valve. Increased destruction and replacement of platelets also may occur.Atrial arrhythmias typically are related to a chronically enlarged left atrium (from mitral valve abnl). Successful cardioversion of A fib to sinus rhythm more likely successful if left atrium is not markedly enlarged, mitral stenosis is mild, & the pt has been in A fib < 6 months. Pts should be anticoagulated before cardioversion to decrease risk of systemic embolization.
21 Doppler-echocardiography In ARHD this identifies & quantitates valve insufficiency & ventricular dysfunction.With mild carditis, Doppler evidence of mitral regurgmay be present during acute phase of disease but resolves in weeks to months. In contrast, patients with moderate-to-severe carditis have persistent mitral and/or aortic regurgitation.The most important features of mitral regurg from acute rheumatic valvulitis are annular dilatation, elongation of the chordae to the anterior leaflet, and a posterolaterally directed mitral regurgitation jet.In chronic rheumatic heart disease, echocardiography may be used to track the progression of valve stenosis and may help determine the time for surgical intervention. The leaflets of affected valves become diffusely thickened, with fusion of the commissures and chordae tendineae. Increased echodensity of the mitral valve may signify calcification.
22 Cardiac Catheterization In ARHD this procedure is not indicated. With chronic disease, heart catheterization has been performed to evaluate mitral and aortic valve disease and to balloon stenotic mitral valves.
23 Electrocardiogram Sinus tachycardia most frequently accompanies ARHD Second-degree (intermittent) and third-degree (complete) AV block with progression to ventricular standstill have been described. Heart block in the setting of rheumatic fever, however, typically resolves with the rest of the disease process.When acute rheumatic fever is associated with pericarditis, ST segment elevation may be present and is marked most in lead II, III, aVF, and V4-V6.Patients with rheumatic heart disease also may develop atrial flutter, multifocal atrial tachycardia, or atrial fibrillation from chronic mitral valve disease and atrial dilation.
24 TreatmentAttempts are made to obtain aspirin blood levels at mg/dL, but, due to variable GI absorption of the drug, stable levels may be difficult to achieve during the inflammatory phase. Aspirin is maintained at anti-inflammatory doses until the signs and symptoms of acute rheumatic fever are resolved or subsiding (6-8 wk) and the acute phase reactants have returned to normal levels.
25 Treatment Con’tmoderate-to-severe carditis indicated by cardiomegaly, CHF, or third-degree heart block, oral prednisone should be added to salicylate therapy. Prednisone should be continued for 2-6 weeks, tapered during the last week of therapy. Adverse effects can be minimized by discontinuing prednisone therapy after 2-4 weeks and maintaining salicylates for an additional 2-4 weeks. Additional treatment for patients with acute rheumatic fever and congestive heart failure should include digoxin, diuretics, supplemental oxygen, bed rest, and sodium and fluid restriction
26 DigoxinDigoxin initiated only after checking electrolyte values and correcting abnormal findings in serum K. The total loading dose is mcg/kg orally with 50% of the dose given initially, followed by 25% of the dose 8 and 16 hours after the initial dose. Maintenance doses typically are 8-10 mcg/kg/d orally in 2 divided doses. For older children and adults, the total loading dose is mg orally, and the maintenance dose is mg/d orally. Therapeutic digoxin levels are present at trough levels of ng/mL. The diuretics most commonly used in conjunction with digoxin for children with congestive heart failure include furosemide and spironolactone, both at doses of 1-2 mg/kg/dose twice per day
27 ProphylaxisPts with RF & carditis but no valve disease should receive prophylactic antibiotics for 10 years or well into adulthood, whichever is longer.Pts with RF & carditis & valve disease should receive antibiotics at least 10 years or until aged 40 years. Patients with RHD require antibiotic prophylaxis before certain surgical and dental procedures to prevent bacterial endocarditis. Patients who have had RF without valve disease do not need prophylaxis. Pts with endocarditis resistant to penicillin should receive erythromycin.
28 ConfusionPreventive and prophylactic therapy is indicated after rheumatic fever and rheumatic heart disease to prevent further damage to valves. The initial course of antibiotics given to eradicate the streptococcal infection also serves as the first course of prophylaxis. An injection of million units of benzathine penicillin G intramuscularly every 4 weeks is the recommended regimen for secondary prevention for most patients in the United States.