Pericardiocentesis is the removal of fluid from the sac around the heart (pericardial effusion). Pericardiocentesis can be an emergency procedure, as pericardial effusion can cause shock symptoms.  The patient is clipped and prepped, an ECG is monitored closely, local anesthesia is given as well as sedation in some patients, and a large catheter is advanced into the pericardial space.  Fluid is then drained and analyzed.