Endomyocardial Fibrosis Workup

Updated: Nov 24, 2014
  • Author: Ali A Sovari, MD, FACP, FACC; Chief Editor: Henry H Ooi, MD, MRCPI  more...
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Workup

Laboratory Studies

Complete blood cell count may show anemia and eosinophilia.

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Chest Radiography

The cardiac silhouette in endomyocardial fibrosis (EMF) may be normal in size, and generalized cardiomegaly is unusual because the ventricles are not typically dilated. The roentgenographic image may exhibit significant enlargement of the atria, and significant right atrial enlargement creates a cardiac silhouette in the shape of the African continent, which is a specific heart shadow sign that has been termed the heart of Africa.

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Echocardiography

Echocardiography is a useful tool and the diagnostic modality of choice when making the diagnosis of EMF and has been demonstrated to successfully differentiate EMF and other processes such as rheumatic heart disease and congenital heart disease. The presence and location of fibrosis as determined by echocardiography correlates well with autopsy findings.

Findings include thickening of the inferior and basal left ventricular wall, apical obliteration, and thrombi adherent to the endocardial surface.

A pericardial effusion is frequently present and may be large.

Although parameters of diastolic function by Doppler echocardiography tend to correlate with the functional status of the patient, because most patients present with later stages of EMF, a restrictive filling pattern in the left ventricle is most common.

Decreased flow propagation velocity (Vp) has been demonstrated in a large percentage of patients with EMF.

Color-flow imaging frequently exhibits tricuspid and mitral regurgitation, believed to be due to retraction or adherence of the atrioventricular valvular apparatus. Spectral Doppler analysis of tricuspid regurgitation frequently reflects an increased pulmonary artery systolic pressure.

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Angiography

Traditionally, angiography has been considered the criterion standard when making the diagnosis of EMF. Left and right ventriculography exhibits distortion of chamber morphology by fibrosis and obliteration and variable degrees of mitral and tricuspid regurgitation. The mushroom sign has been used to describe the shape of the affected ventricle when the apex is obliterated completely by fibrosis.

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Electron Beam Computed Tomography Scanning

Features of EMF observed with this modality were described in the mid 1990s. The fibrotic process is delineated as a band of low attenuation within the endocardium. Obliteration of the apex and inflow tract, when present, is also demonstrated. This method reportedly assists in distinguishing EMF from constrictive pericarditis.

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Cardiovascular Mmagnetic Resonance Imaging

In relatively recent years, the use of cardiovascular magnetic resonance imaging (MRI) has been shown to demonstrate obliterative changes in the ventricles, atrial dilation, and regurgitant atrioventricular valve lesions in patients with EMF. Recent studies have evaluated the role of contrast-enhanced MRI in detecting myocardial fibrosis, which can potentially be a useful diagnostic tool in patients with EMF. [14] However, clinical use of MRI is limited by access to this technology in endemic areas.

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Other Tests

Electrocardiography

Atrial fibrillation in approximately one third of patients with endomyocardial fibrosis. [4] ECG findings may include the following:

  • Low QRS voltage due to myocardial fibrosis
  • Atrioventricular blocks
  • Intraventricular conduction delay and right or left bundle branch blocks
  • Evidence of left (and/or right) atrial enlargement
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Procedures

Cardiac catherization

Cardiac catheterization likely exhibits hemodynamic findings consistent with restrictive cardiomyopathy.

Biopsy

Findings from endomyocardial biopsy may be diagnostic, but this procedure is typically not needed. Biopsy findings may be nondiagnostic when the disease is patchy and sampling sites do not correlate with areas of disease. Because biopsy (especially from the left ventricle) carries some risk, reserve the use of this technique until other diagnostic approaches have been used.

Paracentesis, thoracentesis, and pericardiocentesis

Diagnostic and therapeutic paracentesis, thoracentesis and pericardiocentesis may be indicated in patients with significantly large ascites, pleural effusion, and pericardial effusion, respectively, who do not respond to medical therapy.

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Histologic Findings

The heart size is not usually enlarged in EMF. The ventricular cavities are frequently laden with thrombi and, in severe cases, may be nearly totally obliterated by endocardial thickening and thrombosis. The histologic findings of EMF are characterized by reactive fibrosis associated with a selective increase in type I collagen deposition, subendocardial infarction and fibrosis, and thrombus formation. Additionally, specific features of other diseases, such as those associated with hemochromatosis or glycogen storage disease, are notably absent.

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Staging

Mocumbi and colleagues provided a set of echocardiographic criteria that is useful in staging the disease, studying its progression, and comparing the results of different epidemiologic studies. [8] In this classification, there are 6 major criteria and 7 minor criteria. The diagnosis is considered when 2 major criteria or 1 major and 2 minor criteria are present. A score has been assigned to each criterion and the severity of the disease is measured by this score; a total score of less than 8 indicates mild endomyocardial fibrosis, a score of 8-15 indicates moderate disease, and a score of more than 15 indicates severe disease.

Major criteria

The following are considered major criteria:

  1. Endomyocardial plaques >2 mm in thickness; score: 2
  2. Thin (≤1 mm) endomyocardial patches affecting more than one ventricular wall; score: 3
  3. Obliteration of the right ventricular or left ventricular apex; score: 4
  4. Thrombi or spontaneous contrast without severe ventricular dysfunction; score: 4
  5. Retraction of the right ventricular apex (right ventricular apical notch); score: 4
  6. Atrioventricular valve dysfunction due to adhesion of the valvular apparatus to the ventricular wall; score: 1–4 (depending on the severity of the regurgitation)

Minor criteria

The following are considered minor criteria:

  1. Thin endomyocardial patches localized to 1 ventricular wall; score: 1
  2. Restrictive flow pattern across mitral or tricuspid valves; score: 2
  3. Pulmonary-valve diastolic opening; score: 2
  4. Diffuse thickening of the anterior mitral leaflet; score: 1
  5. Enlarged atrium with normal size ventricle; score: 2
  6. M-movement of the interventricular septum and flat posterior wall; score: 1
  7. Enhanced density of the moderator or other intraventricular bands; score: 1
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