Pericardiocentesis (PCC), also called pericardial tap, is a medical procedure where fluid is aspirated from the pericardium (the sac enveloping the heart).

[1][2] The elastic nature of the pericardium allows it to accommodate a small amount of extra fluid, roughly 80 to 120 mL, in the acute setting.

[2] However, once a critical volume is reached, even small amounts of extra fluid can rapidly increase pressure within the pericardium.

[3][4] Cardiac tamponade is a medical emergency in which excessive accumulation of fluid within the pericardium (pericardial effusion) creates increased pressure.

The removal of the excess fluid reverses this dangerous process, and is often the first treatment for cardiac tamponade due to its speed.

[3][4] Fluid may be analyzed to differentiate a number of conditions, including:[citation needed] There are no absolute contraindications to pericardiocentesis in emergency situations where a patient is hemodynamically unstable.

[3][4] Other relative contraindications include coagulopathies, thrombocytopenia, myocardial rupture, severe pulmonary hypertension, prior thoracoabdominal surgery, prosthetic heart valves, pacemakers and other cardiac devices, inadequate visualization of the effusion on ultrasound during the procedure, and situations in which more appropriate treatment options are available.

[8] A large needle is inserted through the skin of the chest into the pericardium, and the practitioner aspirates the pericardial effusion into a syringe.

[6] Pericardiocentesis can be performed using computed tomography (CT) imaging in cases of complex or loculated effusions or when ultrasound has failed to provide proper visualization.