Pediatric Rheumatic Heart Disease Workup

Updated: Jan 03, 2017
  • Author: Thomas K Chin, MD; Chief Editor: Syamasundar Rao Patnana, MD  more...
  • Print
Workup

Laboratory Studies

Throat culture

Throat culture findings for group A beta hemolytic Streptococcus are usually negative by the time symptoms of rheumatic fever or rheumatic heart disease appear. Attempts should be made to isolate the organism before the initiation of antibiotic therapy to help confirm a diagnosis of streptococcal pharyngitis and to allow typing of the organism if it is isolated successfully.

Rapid antigen detection test

This test allows rapid detection of group A streptococcal antigen and allows the diagnosis of streptococcal pharyngitis and the initiation of antibiotic therapy while the patient is still in the physician's office. Because the rapid antigen detection test has a specificity of greater than 95% but a sensitivity of only 60-90%, a throat culture should be obtained in conjunction with this test.

Antistreptococcal antibodies

The clinical features of rheumatic fever begin at the time antistreptococcal antibody levels are at their peak. Thus, antistreptococcal antibody testing is useful for confirming previous group A streptococcal infection. The elevated level of antistreptococcal antibodies is useful, particularly in patients that present with chorea as the only diagnostic criterion. Sensitivity for recent infections can be improved by testing for several antibodies. Antibody titers should be checked at 2-week intervals in order to detect a rising titer.

The most common extracellular antistreptococcal antibodies tested include antistreptolysin O (ASO), antideoxyribonuclease (DNAse) B, antihyaluronidase, antistreptokinase, antistreptococcal esterase, and anti-DNA. Antibody tests for cellular components of group A streptococcal antigens include antistreptococcal polysaccharide, antiteichoic acid antibody, and anti–M protein antibody.

In general, the ratio of antibodies to extracellular streptococcal antigens rises during the first month after infection and then plateaus for 3-6 months before returning to normal levels after 6-12 months. When the ASO titer peaks (2-3 wk after the onset of rheumatic fever), the sensitivity of this test is 80-85%. The anti-DNAse B has a slightly higher sensitivity (90%) for detecting rheumatic fever or acute glomerulonephritis. Antihyaluronidase results are frequently abnormal in rheumatic fever patients with a normal level of ASO titer and may rise earlier and persist longer than elevated ASO titers during rheumatic fever.

Acute phase reactants

The C-reactive protein and erythrocyte sedimentation rate are elevated in rheumatic fever due to the inflammatory nature of the disease. Both tests have a high sensitivity but low specificity for rheumatic fever. They may be used to monitor the resolution of inflammation, detect relapse when weaning aspirin, or identify the recurrence of disease.

Heart reactive antibodies

Tropomyosin is elevated in acute rheumatic fever.

Rapid 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.

Next:

Electrocardiography

On ECG, sinus tachycardia most frequently accompanies acute rheumatic heart disease. Alternatively, some children develop sinus bradycardia from increased vagal tone. No correlation between bradycardia and the severity of the carditis is noted.

First-degree atrioventricular (AV) block (prolongation of the PR interval) is observed in some patients with rheumatic heart disease. This abnormality may be related to localized myocardial inflammation involving the AV node or to vasculitis involving the AV nodal artery. First-degree AV block is a nonspecific finding and should not be used as a criterion for the diagnosis of rheumatic heart disease. Its presence does not correlate with the development of chronic rheumatic heart disease.

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. Left atrial enlargement may be seen in patients with mitral stenosis. Left ventricular hypertrophy may be observed in patients with significant mitral insufficiency or aortic insufficiency.

Previous
Next:

Imaging Studies

Chest roentgenography

Cardiomegaly, pulmonary congestion, and other findings consistent with heart failure may be seen on chest radiography. When the patient has fever and respiratory distress, chest radiography helps differentiate heart failure from rheumatic pneumonia.

Doppler-echocardiography

In acute rheumatic heart disease, Doppler-echocardiography identifies and quantitates valve insufficiency and ventricular dysfunction. Studies in Cambodia and Mozambique demonstrated a 10-fold increase in the prevalence of rheumatic heart disease when echocardiography is used for clinical screening compared with strictly clinical findings. [12]

With mild carditis, Doppler evidence of mitral regurgitation may be present during the 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 echocardiographic features of mitral regurgitation from acute rheumatic valvulitis are annular dilatation, elongation of the chordae to the anterior leaflet, and a posterolaterally directed mitral regurgitation jet.

During acute rheumatic fever, the left ventricle is frequently dilated in association with a normal or increased fractional shortening. Thus, some cardiologists believe that valve insufficiency (from endocarditis), rather than myocardial dysfunction (from myocarditis), is the dominant cause of heart failure in acute rheumatic fever.

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.

The image below depicts the typical systolic mitral insufficiency jet observed with rheumatic heart disease.

Parasternal long-axis view demonstrating the typic Parasternal long-axis view demonstrating the typical systolic mitral insufficiency jet observed with rheumatic heart disease (blue jet extending from the left ventricle [LV] into the left atrium [LA]). The jet is typically directed to the lateral and posterior wall. Ao = aorta; RV = right ventricle.

The image below depicts the typical diastolic aortic insufficiency jet observed with rheumatic heart disease.

Parasternal long-axis view demonstrating the typic Parasternal long-axis view demonstrating the typical diastolic aortic insufficiency jet observed with rheumatic heart disease (red jet extending from the aorta [Ao] into the left ventricle [LV]). LA = left atrium; RV = right ventricle.

The World Heart Federation has published guidelines for identifying individuals with rheumatic heard disease without a clear history of acute rheumatic fever. Based on 2-dimensional (2D) imaging and pulsed and color Doppler interrogation, patients are divided into 3 categories: definite rheumatic heart disease, borderline rheumatic heart disease, and normal. For pediatric patients (defined as age < 20 y), definite echo features include pathologic mitral regurgitation (MR) and at least 2 morphological features of rheumatic heart disease of the mitral valve, mitral stenosis mean gradient of more than 4 mm Hg, pathological aortic regurgitation and at least 2 morphological features of rheumatic heart disease of the aortic valve, or borderline disease of both the aortic valve and mitral valve. [16]

Handheld echocardiography has been investigated as a screening tool and found to be 90% sensitive and 92% specific for identifying patients with rheumatic heart disease in Ugandan children. [17]

Heart catheterization

In acute rheumatic heart disease, this procedure is not indicated. With chronic disease, heart catheterization has been performed to evaluate mitral and aortic valve disease and preparatory to balloon valvuloplasty of the stenotic mitral valves.

Postcatheterization precautions include hemorrhage, pain, nausea and vomiting, and arterial or venous obstruction from thrombosis or spasm. Complications may include mitral insufficiency after balloon dilation of the mitral valve, tachyarrhythmias, bradyarrhythmias, and vascular occlusion.

Previous
Next:

Histologic Findings

Pathologic examination of the insufficient valves may reveal verrucous lesions at the line of closure.

Aschoff bodies (perivascular foci of eosinophilic collagen surrounded by lymphocytes, plasma cells, and macrophages) are found in the pericardium, perivascular regions of the myocardium, and endocardium. The Aschoff bodies assume a granulomatous appearance with a central fibrinoid focus and eventually are replaced by nodules of scar tissue.

Anitschkow cells are plump macrophages within Aschoff bodies.

In the pericardium, fibrinous and serofibrinous exudates may produce an appearance of "bread and butter" pericarditis.

Previous