Atrial fibrillation (AF) usually causes the heart's lower chambers, the ventricles, to contract faster than normal.
When this happens, the ventricles can't completely fill with blood. Thus, they may not be able to pump enough blood to the lungs and body. This can lead to signs and symptoms, such as:
During AF, the heart's upper chambers, the atria, don't pump all of their blood to the ventricles. Some blood pools in the atria. When this happens, a blood clot (also called a thrombus) can form.
If the clot breaks off and travels to the brain, it can cause a stroke. (A clot that forms in one part of the body and travels in the bloodstream to another part of the body is called an embolus.)
Blood-thinning medicines that reduce the risk of stroke are an important part of treatment for people who have AF.
Heart failure occurs if the heart can't pump enough blood to meet the body's needs. AF can lead to heart failure because the ventricles are beating very fast and can't completely fill with blood. Thus, they may not be able to pump enough blood to the lungs and body.
Fatigue and shortness of breath are common symptoms of heart failure. A buildup of fluid in the lungs causes these symptoms. Fluid also can build up in the feet, ankles, and legs, causing weight gain.
Lifestyle changes, medicines, and procedures or surgery (rarely, a mechanical heart pump or heart transplant) are the main treatments for heart failure.
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