Understanding the Pericardium (Pericardial
Your heart is surrounded by a double-layered membrane, called
the pericardium or pericardial sac. This membrane keeps your heart in place in
your chest cavity, restricts the expansion of your heart when your blood volume
increases, and helps to protect your heart. The inner layer of the pericardium
is attached to your heart muscle.
There is a very small amount of fluid called pericardial fluid
in the pericardial sac. This fluid helps to decrease friction between the
pericardial layers. It also allows for smooth movement of the heart when it
Pericardiocentesis, also known as a pericardial tap, is a test
used to diagnose issues related to the pericardium.
What Is Pericardiocentesis?
Pericardiocentesis is an invasive procedure. It uses a needle
and catheter to obtain fluid from your pericardium. The fluid can then be sent
to a laboratory for microscopic examination for abnormal cells.
This test is often used to help diagnose an infection, cancer,
or the cause of extra fluid surrounding your heart. The procedure can also be
used to ease symptoms such as shortness of breath.
When too much fluid is trapped in your pericardium, this is
called pericardial effusion. This can prevent your heart from pumping normally
because the extra fluid causes compression. Pericardial effusion can lead to a
life-threatening condition called cardiac tamponade. In this condition, your
heart becomes too compressed to function normally. Cardiac tamponade is life
threatening and must be treated immediately.
Causes of Pericardial Effusions
There are many causes for the buildup of fluid in the
- kidney failure
- hypothyroidism, or underactive thyroid
- radiation therapy for cancers
- medications such as hydralazine for
hypertension, isoniazid (Nydrazid) for tuberculosis, and phenytoin (Dilantin)
- piercing or blunt trauma near the heart
- cancer of the heart or pericardium or metastatic
cancer from other organs
- autoimmune diseases such as systemic lupus
erythematosus and rheumatoid arthritis
- viral, bacterial, fungal, or parasitic
- congestive heart failure
- ventricular aneurysm rupture
How Do I Prepare for Pericardiocentesis?
This procedure will be performed in a hospital. Tell your doctor
about any medications and supplements you take, ask your doctor if you should
adjust your medications the day of the procedure, and tell your doctor if you
are diabetic. You will usually not be allowed anything to eat or drink for six
hours before your appointment.
You will be allowed to go home after the procedure, but you will
need someone else to drive you home.
What Can I Expect During the Procedure?
A pericardiocentesis is usually performed in an intensive care
unit or cardiology department in a hospital, but it may be done at your bedside
or in the emergency department if you experience pericardial effusion.
You will be asked to lie down on an exam table and positioned at
a 60-degree angle. An IV will be started to give you any fluids or medications
in case you have a severe drop in blood pressure or slowed heartbeat during the
procedure. The skin below and around your breastbone will be cleaned, and a
local numbing agent will be applied. You may also be given a sedative, but you
will remain awake for the procedure.
A needle is then inserted into your pericardial sac. You might
feel some pressure while the needle goes in. It is guided by echocardiogram,
which gives your doctor a moving picture of your heart, similar to an
ultrasound. This will also help monitor fluid drainage. Once the needle has
been placed correctly, your doctor will replace it with a very thin tube known
as a catheter. The procedure itself takes 20 to 60 minutes.
The catheter then stays in place to let fluid drain through it
into a container, sometimes for several hours. Once the fluid has drained, the
catheter is removed.
Depending on the institution, your doctor, your outlook, and the
cause of effusion, more invasive surgical drainage than needle
pericardiocentesis may be necessary.
Are There Any Possible Side Effects?
As with any invasive procedure, there are risks to
pericardiocentesis. Your doctor will go over all the risks and have you sign a
consent form before the procedure.
Possible risks include:
- heart attack
- collapsed lung
- abnormal heart rhythm
- puncture of the heart muscle
After the procedure, the site of the catheter should be checked
regularly for any signs of infection. Your blood pressure and pulse will be
monitored after the procedure, and your doctor will decide when to send you
home. If you were given a sedative, someone will have to drive you home, since
you won’t be allowed to drive yourself directly following the procedure.
Testing the Fluid
If the drained fluid needs to be tested for infections or
cancer, your doctor will send it to a laboratory. If the fluid shows signs of
an infection, the infection may be due to an autoimmune disorder, hypothyroidism,
rheumatic fever, immunosuppressants, chest radiation, cancer, or kidney
failure. Sometimes the cause of the infection is unknown, and your pericardium
is inflamed for no apparent reason. This is called idiopathic pericarditis.
In some people, especially those with advanced cancer, fluid may
continue to build up in the pericardium. A catheter may be put in place to
ensure continual drainage and prevent repeated pericardiocentesis. Sometimes a
surgical procedure called pericardial sclerosis is necessary to close the space
around your heart so fluid can’t accumulate in the sac surrounding your heart.
What Do Abnormal Results Mean?
If abnormal results are found in the fluid, your doctor may be
able to determine the cause of fluid accumulation. Talk with your doctor about
what your results mean and whether there is a chance of the fluid coming back.
They can discuss your treatment options with you.