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What is the Pericardial Sac?

Mary McMahon
Mary McMahon
Mary McMahon
Mary McMahon

The pericardial sac is a double walled layer of tissue which surrounds the heart and the large blood vessels which supply it. It acts essentially like a protective envelope for the heart, permitting normal heart movement within the confines of the sac while insulating the heart and great blood vessels. The outer layer of the sac is attached to the diaphragm and the sternum to anchor it in place.

This anatomical structure is also known as the pericardium. The outer layer, called the parietal pericardium, is very tough and fibrous, and makes a loose envelope. The inner layer, the visceral pericardium, is more flexible and hugs the heart closely. The pocket between the layers is filled with pericardial fluid, which acts as a lubricant, allowing the heart and visceral pericardium to move around inside the outer layer of the pericardial sac with each heartbeat.

The pericardial sac, also known as the pericardium, is a double walled layer of tissue that surrounds the heart.
The pericardial sac, also known as the pericardium, is a double walled layer of tissue that surrounds the heart.

Anatomical drawings of the heart often depict it without the pericardial sac, so that people can see the details of the heart and the vessels which supply it with blood. In surgery, it is necessary to cut through the sac to access the heart, a delicate procedure which is usually performed by a specialist who has received extensive training in heart surgery to learn how to perform such procedures safely and quickly.

Excess fluid between the heart and the pericardium is referred to as pericardial effusion.
Excess fluid between the heart and the pericardium is referred to as pericardial effusion.

Two different medical issues can arise with the pericardial sac. The first is pericardial effusion. This happens when there is too much fluid between the layers. This compresses the heart, and can lead to cardiac tamponade, in which the chambers of the heart cannot fill enough because of the pressure. The treatment for this is to drain off the excess fluid before the patient develops severe complications such as stroke. Fans of medical dramas may have seen dramatic scenes in which needles are plunged into the pericardial sac to drain the fluid buildup.

Those with a compromised immune system should take precautions to prevent viral, bacterial and fungal infections that affect the pericardial sac.
Those with a compromised immune system should take precautions to prevent viral, bacterial and fungal infections that affect the pericardial sac.

Another issue which can arise is pericarditis, an inflammation of the pericardial sac which can be associated with viral, bacterial, or fungal infections. It is necessary to treat the underlying infection to resolve the inflammation. People with compromised immune systems are an increased risk of developing this condition because their bodies cannot fight off the infection as effectively. Medications can be administered to treat the infection, and the patient can also be monitored for signs of complications which might suggest that the heart is being compromised by the inflammation.

Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a WiseGEEK researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

Learn more...
Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a WiseGEEK researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

Learn more...

Discussion Comments

anon265760

What does the pericardial sac look like -- in detail?

blackDagger

How does a person get something like pericarditis? I mean, the heart and the sac that surrounds it are safely tucked inside of the body. It isn’t like an infected wound or your ears when inflamed, which are exposed to the outside world in a much bigger way.

And, more importantly, how does one prevent something as scary as inflammation of the pericardium? It seems like this is one of those hugely terrifying possibilities that is made even scarier because it is difficult to understand.

Domido

I had no idea that the pericardial sac filling with fluid could be just as dangerous as a person having a heart attack. Heck, I didn’t really know anything about the pericardium at all.

But when my father in law had a mix up with his medication and ended up not having his fluid pills we became very aware quickly what kinds of dangers this holds.

He is a bigger man, and we didn’t really notice the extra water that he was holding at first. But then he started to become short of breath and just generally ill feeling.

We ended up rushing him to the emergency room. Come to find out his pericardial sac function was greatly inhibited because it was overfilled with fluids. He was in serious danger of going into cardiac arrest.

Fortunately, he recovered and his fluid pill issue was rectified. Once he lost 30 pounds worth of fluid, we realized how seriously he could have been hurt.

anon179102

After heart surgery does the pericardial-sac return to normal i.e,, refill with fluid?

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    • The pericardial sac, also known as the pericardium, is a double walled layer of tissue that surrounds the heart.
      By: reineg
      The pericardial sac, also known as the pericardium, is a double walled layer of tissue that surrounds the heart.
    • Excess fluid between the heart and the pericardium is referred to as pericardial effusion.
      By: arcticsilence
      Excess fluid between the heart and the pericardium is referred to as pericardial effusion.
    • Those with a compromised immune system should take precautions to prevent viral, bacterial and fungal infections that affect the pericardial sac.
      By: DjiggiBodgi.com
      Those with a compromised immune system should take precautions to prevent viral, bacterial and fungal infections that affect the pericardial sac.