What is pericardiocentesis?

Pericardiocentesis (say "pair-uh-kar-dee-oh-sen-TEE-sus") is a test that is done to find the cause of extra fluid around your heart. It also can be a treatment to drain extra fluid and relieve pressure on your heart. The sac that surrounds the heart is called the pericardium. Normally, there is a small amount of fluid in it. This fluid surrounds and helps cushion your heart.

Sometimes too much fluid builds up in the sac. This is called pericardial effusion. Extra fluid can be caused by many things, including pericarditis (inflammation of the sac), heart attack, surgery, kidney failure, infection, some cancers, and certain diseases such as lupus. Sometimes the cause is not known.

How is it done?

You may get a mild sedative to help you relax. You will get a shot of anesthetic to numb your skin and deeper tissues. Then a long, thin needle will be carefully inserted just below your breastbone. (In some cases, the needle is inserted between your ribs on the left side, over your heart.)

The needle is then slowly pushed through the pericardial sac into the space between the sac and your heart. This is where the extra fluid is.

Your doctor may use an echocardiogram to help guide the needle. Or an X-ray camera may be used to guide it.

The doctor may guide a thin plastic tube along the needle into the space between the sac and your heart. The fluid drains out through the tube. Some fluid may be saved and sent to a lab for tests. At different times during the procedure, you may be asked to hold your breath. You must remain very still throughout the procedure.

After some or all of the fluid is drained, the tube may be removed right away. Or the tube may be left in for up to a few days. Pressure is applied to the injection site for several minutes to stop any bleeding.

After the procedure, you will have a chest X-ray to check for possible puncture and collapse of your left lung. You will be closely watched for several hours.

What happens after the test?

Some of the fluid may be tested to try to find the cause of the fluid buildup. Some results will be ready within hours. Others may take days or weeks.