Causes of Blood Clots in the Heart

Instructor: Adrianne Baron

Adrianne has a master's degree in cancer biology and has taught high school and college biology.

There are a handful of possible causes of blood clots forming or flowing into the heart. We will discuss these and how they occur to gain a better understanding of blood clots in the heart.

Blood Clots

Perhaps you have been a little accident prone throughout your life. You get scrapes and cuts on your hands, arms, elbows, and knees regularly. They bleed, of course, and then they suddenly stop bleeding. The bleeding stopped because a blood clot, or clump of blood cells and proteins, formed. This was a good thing because the blood clot kept you from bleeding to the point that you lost all blood from your body. While this is a great instance of a blood clot forming, there are some not-so-great and even life-threatening instances of blood clots forming.

There are two different types of blood clots that can occur in the body. The first is when a blood clot forms and stays where it formed, which is known as a thrombus. A thrombus can eventually break free from where it forms and enter the bloodstream, which then makes it an embolus. A thrombus can form in the heart or an embolus can flow to the heart and get stuck there.

Thrombus and embolus are the two types of blood clots
Diagram of blood clot formation

Blood Clots in the Heart

There are a few causes of blood clots in the heart. The first cause has to do with the heart itself. The heart needs to contract strongly enough to allow blood to circulate throughout the body and come back to the heart. If the heart isn't pumping properly, then this can cause blood to flow slower than it is supposed to, which allows a thrombus to form. The thrombus that forms may very well be in one of the blood vessels of the heart.

Blood flow could also be altered by atherosclerosis, which is the narrowing of blood vessels due to plaque build-up and the inflammation that occurs due to this build-up. This will cause blood to get backed up, which once again allows blood clots to form. A blood clot formed this way could form in the heart or somewhere else in the body and then flow to the heart.

Atherosclerosis can cause blood clots to form in the heart and body
Diagram showing atherosclerosis

The presence of another condition in the body, deep vein thrombosis, a condition where blood clots form within the veins in the inner portion of the arms or legs, is another cause of blood clots in the heart. The blood clots can get loose from the arms or legs and flow to the heart. You will often see this abbreviated as DVT.

We talked about our blood clotting when we cut ourselves. This same mechanism works within the body too. Blood clots in the heart could come from injury to a blood vessel in the heart. The injury could come from a breakdown in the wall of the blood vessel due to high blood pressure or too much sugar in the blood. The proteins in the blood will begin to connect to each other and then stick to blood cells until a blood clot is formed over the damaged portion of the blood vessel in the heart.

Finally, the last thing that can happen to cause blood clots in the heart is the presence of too many of the proteins that cause blood to clot in the blood. An excessive amount of clotting proteins may make blood clot anywhere, including in the heart, for no apparent reason.

To unlock this lesson you must be a Member.
Create your account

Register to view this lesson

Are you a student or a teacher?

Unlock Your Education

See for yourself why 30 million people use

Become a member and start learning now.
Become a Member  Back
What teachers are saying about
Try it now
Create an account to start this course today
Used by over 30 million students worldwide
Create an account