Pediatric Nonviral Myocarditis Workup
- Author: Stuart Berger, MD; Chief Editor: P Syamasundar Rao, MD more...
Echocardiography is critical in diagnosing myocarditis. Typically, the presence of diminished ventricular function with dilation of 1 or several chambers of the heart becomes obvious. Echocardiography rules out pericardial effusion or structural congenital heart disease as the etiology of the symptoms.
Sinus tachycardia out of proportion to the degree of fever may be noticeable in patients with myocarditis. Arrhythmias, including ST-T wave changes in as many as 80% of patients, may be associated with myocarditis. These changes may be sensitive indicators of myocardial ischemia, or they may be nonspecific findings.
The major purposes of a tissue biopsy are to establish a diagnosis of myocarditis and to classify the stage of disease as acute, healed, or chronic. The specific histologic findings differ based on the particular etiologic agent associated with myocarditis.
The role of endomyocardial biopsy in the diagnosis of myocarditis remains controversial. Biopsy may present somewhat of a risk in the acutely ill and unstable patient, and histologic diagnosis may not be easy.
Typical sampling usually includes small areas of the right ventricle. Because myocarditis may be focal and may primarily involve the left ventricle, results of the sampling techniques used may not fully represent the true incidence of myocarditis. In other words, a negative biopsy result does not rule out myocarditis.
A major problem with endomyocardial biopsy is the possibility of overinterpretation or misinterpretation of the biopsy specimen. In addition, clinicians argue that the results of endomyocardial biopsy may not change the treatment of myocarditis. This may be true, at least until a clearer role emerges for immunosuppression therapy in patients with this disease. Little work in pediatric patients has been done in this area.
The high-contrast and high-resolution fluorescent imaging of confocal laser scanning microscopy and super-resolution microscopy may potentially increase the diagnostic yield of endomyocardial biopsy. These modalities appear to provide improved quantitative digital analysis and may thereby improve precision and accuracy in the evaluation of critical pathologic features.
Performing a biopsy to establish a subset of pediatric patients with active myocarditis may be useful in order to study different therapies in a controlled, prospective manner.
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