Cardiac Tamponade? Tell me more!

This week I began to look into the pathophysiology of Cardiac Tamponade, that is, what happens during a cardiac tamponade? I found a fantastic YouTube video that explains a cardiac tamponade very well.  It is a cheesy hand drawn video, but it keeps it simple and is entertaining to watch.

Excellent explanation of Cardiac Tamponade

Basically, the sac surrounding the heart tissue fills up with some sort of fluid.  This reduces the amount of space the heart has to pump.  As the sac fills with fluid, the heart becomes more constricted and cannot contract effectively.

Mosby's Medical Dictionary, 8th edition. © 2009, Elsevier

Since the pericardial sac is not flexible, it cannot expand very much with the increased fluid volume. This increases the pressure on the heart.  As the pressure builds, the stroke volume of the heart begins to decrease.  Eventually, obstructive shock develops, leading to cardiac arrest if left untreated.  

Mortality from cardiac tamponade is 100% if left untreated, or if the fluid isn't removed.  

Citation

Hasan Ali Gumrukcuoglu, Dolunay Odabasi, Serkan Akdag, and Hasan Ekim, “Management of Cardiac Tamponade: A Comperative Study between Echo-Guided Pericardiocentesis and Surgery—A Report of 100 Patients,” Cardiology Research and Practice, vol. 2011, Article ID 197838, 7 pages, 2011. doi:10.4061/2011/197838

Epidemiology of Cardiac Tamponade

Who gets a cardiac tamponade??

Good question. After doing quite a bit of research, it has become clear that the numbers of cardiac tamponade are poorly documented in the United States. I was unable to find a clear article that covered the distribution of cardiac tamponade.  However, I found some information regarding those most at risk.  

First of all, it seems that cardiac tamponade occurs in about 2 out of 10,000 cases.  In younger ages, most cases of cardiac tamponade are caused by trauma or HIV, but in the elderly patients, it is more commonly associated with malignancy and/or renal failure.  In the younger ages, there is generally more cases of boys than of girls with cardiac tamponade. 

In one study I looked into, they researched the cause of 106 cases of pericardial effusion.  They found that the most prominent causes were cancer (36%), idiopathic (30%), meaning there was no known cause, and infection (21%).  

In another study, they examined the frequency of pericardial effusions in patients with HIV.  The study found that of their 187 patients with pericardial effusions, approximately 14 of them were positive for HIV.  

Another study concluded that there is a much higher incidence of pericardial effusion in patients with AIDS.  Also, the development of effusion in patients with HIV suggests the transition to AIDS.

So while it is hard to determine the exact numbers of cardiac tamponade in the United States, we know that it is more prevalent in certain populations.  

References:

Eisenberg, M., Gordon, A., & Schiller, N. (1992). HIV-associated pericardial effusions. Chest, 102(3), 956-958.

Richardson, L. (2014). Cardiac tamponade. JAAPA: Journal Of The American Academy Of Physician Assistants (Lippincott Williams & Wilkins), 27(11), 50-51. doi:10.1097/01.JAA.0000455653.42543.8a

Not an hors d'œuvre made of hearts!

What in the world is a Cardiac Tamponade? Funny sounding name for something that can be very deadly if left untreated.  Let's break it down.  Obviously it has to do with the heart (hence cardiac).  What is a tamponade though? Generally a tamponade is the blockage or plugging of a hole that is bleeding.  So a cardiac tamponade is the blockage of blood coming out of the heart? Well, its  not quite that simple and that definition leaves something to be desired.  In the end, if left untreated, blood will not be able to get out of the heart, but not for the reasons we might think.  

Simply, a cardiac tamponade is when fluid (can be blood or pus, clots, or even a gas) collects in the pericardium, which is the sac that surrounds the heart. As the fluid builds up it puts pressure on the heart and the heart is unable to pump blood efficiently, ending up with no blood being able to pump out of the heart. 

Okay, so we know what this disease is, but why do we care, when do we see this disease.  Well, cardiac tamponade can occur from penetrating chest wounds (the gory trauma we expect in EDs).  It can also occur from blunt chest trauma, maybe getting hit in the chest with a baseball, or being in a car accident.  There are other causes of cardiac tamponade, but they are less exciting and I will cover those later.   

That's all for now, but here is a picture of what a cardiac tamponade looks like:

(https://thernhangout.wordpress.com/category/cardiac-2/)