Blood clots in the heart

My uncle was scheduled for Raiofrequency ablation treatment yesterday; however, this procedure was canceled and delayed for three weeks. Doctors found blood clots in my uncle's heart during the TransEsophageal Echo (TEE) procedure, therefore, they stopped the electrical cardioversion procedure. I was concerned about his blood clot condition and why doctors have to stop the procedure. After few hours of research on this topic, I understood that blood clots can disrupt blood flow. These clots may block the blood vessels leading to important organs in the body such as the brain and cause stroke.

According to Blood Clots, an article on MedicineNet website, “Blood clots form when there is damage to the lining of a blood vessel, either an artery or a vein. The damage may be obvious, such as a laceration, or may occur on the microscopic level. As well, blood will begin to clot if it stops moving and becomes stagnant. Blood clots in a vein occur when a person becomes immobilized and muscles are not contracting to push blood back to the heart. This stagnant blood begins to form small clots along the lining walls of the vein that gradually grow to partially or completely occlude the vein. An analogy to this process is a slow moving river. Over time, weeds and algae start to accumulate along the banks of the river where the water flows more slowly. Gradually, as the weeds start to grow, they begin to invade the center of the river because they can withstand the pressure of the water. Blood clots can also form in the heart. In atrial fibrillation, the atrium or upper chamber of the heart does not beat in an organized manner. Instead, it jiggles, and blood tends to become stagnant along the walls of the atrium. Over time, this may cause small blood clots to form. Clots can also form in the ventricle after a heart attack when part of the heart muscle is injured and unable to contract normally. Since the damaged area doesn't contract with the rest of the heart, blood can start to pool or stagnate, leading to clot formation.” I wanted to know what causes blood clots in the heart. The above article also provided the answer to my curious question.

Small clots may form along the walls the upper chambers of the heart. If these clots break off and travel in the bloodstream to the brain, they may block an artery and cause a stroke. This explained why doctors stopped the electrical cardioversion procedure on my uncle heart.

Below is a picture of blood clot.

Source:

http://www.medicinenet.com/blood_clots/page2.htm#