Pericarditis laboratory studies


 * Associate Editor-In-Chief: Varun Kumar, M.B.B.S.

Overview
Non-specific markers of inflammation are generally elevated in pericarditis. This include the CBC, elevated C-reactive protein, ESR. The cardiac troponin is elevated if there is injury to the underlying myocardium, a condition termed myopericarditis. Diagnostic pericardiocentesis and biopsy help in identifying an underlying infectious or malignant process.

Inflammatory Markers
The following inflammatory markers are often elevated:


 * CBC
 * C-reactive protein
 * Erythrocyte sedimentation rate (ESR)

Markers of Myonecrosis
The following markers of myonecrosis may be elevated if there is involvement of the underlying myocardium:
 * Creatine Kinase: Acute pericarditis may be associated with a modest increase in serum creatine kinase MB (CK-MB) depending upon the extent of involvement of the underlying myocardium.
 * Cardiac troponin I (cTnI).
 * LDH: depends on the extent of myocardial involvement
 * Serum myoglobin

Gallium-67 Imaging
Gallium-67 scanning may help identify inflammatory and leukemic infiltrations.

Diagnositic Pericardiocentesis
Pericardial fluid should be aspirated and tested for presence of malignant cells and tumor markers particularly in patients with hemorrhagic effusion without preceding trauma. However, hemorrhagic pericarditis in developing countries could be due to tuberculosis. Sensitivity of cytological analysis of pericardial fluid for malignant cells were 67%, 75% and 92% in different studies with specificity of 100%. Immunohistochemistry can be used to distinguish between the malignant cells and their possible origin.

Fluid aspirated can also be used for following tests:
 * Gram staining
 * Acid-fast staining
 * Culture

Pericardial Biopsy
If the clinical suspicion of malignancy is high, and if the results of cytology testing from the pericardiocentesis are negative, consideration should be given to performing a pericardial biopsy. This can be performed via either a subxiphoid or transthoracic pericardiostomy or alternatively by pericardioscopy. An advantage of pericardioscopy is that it assists in the direct visualization of pericardium and collecting the biopsy sample. Pericardioscopy has an excellent sensitivity of 97% which compares quite favorably to a blind biopsy which has a low sensitivity of 55-65%.