This is a laboratory test performed on a specimen of pericardial fluid to isolate and identify organisms that cause infection.

The fluid must first be taken from the sac surrounding the heart. In some people, a cardiac monitor may be placed prior to the test to monitor for heart disturbances. Patches called electrodes will be placed on the chest similar to during an ECG. A chest x-ray or ultrasound may be done before the test.

The skin of the chest will be cleaned with antibacterial soap. A trained physician, often a cardiologist, will take the sample. A small needle is inserted into the chest between the ribs into the pericardium, which is the thin sac that surrounds the heart, and a small amount of fluid is withdrawn.

There will be a sensation of pressure and some pain as the needle is inserted into the chest. An ECG and chest x-ray may be done after the test. Sometimes the pericardial fluid is taken during open heart surgery.

Samples of the fluid are placed in various culture media (substances that encourage bacterial growth) in the laboratory. The media is observed for the growth of colonies of microorganisms (bacteria). Certain biochemical tests can identify certain organisms while others require blood tests or tissue culture to identify organisms.

It can take anywhere from a few hours to several weeks to get the test results depending on the type of organism.

You will be asked not to eat of drink anything for several hours before the test. A chest x-ray or ultrasound may be done before the test to identify the area of fluid collection.

There will be some pressure and discomfort associated with the removal of the fluid from the sac surrounding the heart. Your doctor should be able to give you enough pain medicine so that the procedure does not hurt very much.

The test is performed when an infection of the heart is suspected or when a pericardial effusion is present.

The absence of organisms is normal.

An infection of the pericardium may be present. The specific organism may be identified. Additional testing (sensitivity) can be used to determine which antimicrobial treatment will be most effective.

Additional conditions under which the test may be performed:

• Pericarditis

There is a risk of puncturing the heart or the lung with this procedure. Introducing infection into the area is another rare, but potential, risk.