Pericardiocentesis is an invasive procedure in which the physician removes (aspirates) fluid from the pericardium – a protective fluid-filled sac surrounding the heart. This may be an emergency procedure to treat cardiac tamponade, a scheduled procedure to treat less severe fluid buildup, or a diagnostic test to assess for infection or cancer.

The procedure involves the insertion of a needle into the pericardium to withdraw fluid. A catheter may also be inserted to allow further drainage. If necessary, the catheter will remain in place for several days to complete the process. Therefore, the patient should prepare to spend several days in the hospital, though only an overnight stay may be required.