Atrial fibrillation is an abnormal heart rhythm. The heart's electrical system normally sends regularly spaced signals. These signals tell the heart muscle to contract or beat.
The heart has two upper chambers called atria. It also has two lower chambers called ventricles. Each signal starts in the atria and travels to the rest of the heart. In atrial fibrillation, the electrical signals from the atria are fast and irregular. The atria shake instead of contract. Some signals do not reach the ventricles and the ventricles continue pumping. This pumping is usually irregular and sometimes rapid. This rhythm can reduce the heart’s ability to pump blood out to the body. Blood left in the heart chambers can form clots. These clots may sometimes break away and travel to the brain. This can cause stroke.
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In most cases, atrial fibrillation is due to an existing heart condition. Atrial fibrillation can also occur in people who do not have structural heart problems. A thyroid disorder or other condition may cause the abnormal rhythm. The cause of atrial fibrillation is sometimes unknown.
Atrial fibrillation is more common in men and in people aged 55 years and older. Other factors that may increase your chance of atrial fibrillation include:
Symptoms can be mild to severe. This depends on your heart function and overall health. Some people may not notice any symptoms.
In those that have them, symptoms may include:
The doctor will:
You doctor will order blood tests to help diagnose the problem.
The goals of treatment are to:
Your doctor may find another condition that is causing atrial fibrillation. This condition may be treated. In some cases, heart rhythm problems return to normal without treatment.
Treatment options include:
Medications may be used to:
Maintaining a healthy weight through diet and exercise may reduce the frequency, duration, and severity of atrial fibrillation episodes.
If anti-clotting medication can not be tolerated a procedure called left atrial appendage closure (LAAC) may be considered. This procedure uses a device to seal a small pouch in the top of the heart where clots tend to form. LAAC can help reduce the risk of clots and stroke for people with atrial fibrillation who can not tolerate medication treatments.
American Heart Association
Heart Rhythm Society
Canadian Cardiovascular Society
Heart and Stroke Foundation
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Atrial fibrillation. CardioSmart website. Available at: http://cardiosmart.org/HeartDisease/CTT.aspx?id=222. Accessed November 9, 2012.
Cardioversion. Cleveland Clinic website. Available at: http://my.clevelandclinic.org/services/heart/services/cversion. Updated December 28, 2011. Accessed November 9, 2012.
Explore atrial fibrillation. National Heart Lung and Blood Institute website. Available at: http://www.nhlbi.nih.gov/health/health-topics/topics/af. Updated July 1, 2011. Accessed November 9, 2012.
Left atrial appendage and closure. Cleveland Clinic website. Available at: http://my.clevelandclinic.org/services/heart/services/arrhythmia-treatment/left-atrial-appendage-closure. Updated May 2016. Accessed July 14, 2016.
12/13/2010 DynaMed Plus Systematic Literature Surveillancehttp://www.dynamed.com/topics/dmp~AN~T115288/Atrial-fibrillation: Lubitz SA, Yin X, et al. Association between familial atrial fibrillation and risk of new-onset atrial fibrillation. JAMA. 2010;304(20):2263-2269.
5/11/2012 DynaMed Plus Systematic Literature Surveillancehttp://www.dynamed.com/topics/dmp~AN~T115288/Atrial-fibrillation: Osbak PS, Mourier M, et al. A randomized study of the effects of exercise training on patients with atrial fibrillation. Am Heart J. 2011;162(6):1080-1087.
1/2/2014 DynaMed Plus Systematic Literature Surveillancehttp://www.dynamed.com/topics/dmp~AN~T115288/Atrial-fibrillation: Abed HS, Wittert GA, et al. Effect of weight reduction and cardiometabolic risk factor management on symptom burden and severity in patients with atrial fibrillation: A randomized clinical trial. JAMA. 2013;310(19):2050-2060.
7/1/2015 DynaMed Plus Systematic Literature Surveillancehttp://www.dynamed.com/topics/dmp~AN~T115288/Atrial-fibrillation: Qureshi WT, O'Neal WT, Khodneva Y, et al. Association between opioid use and atrial fibrillation: The Reasons for Geographic and Racial Differences in Stroke (REGARDS) study. JAMA Intern Med. 2015;175(6):1058-1060.
Last reviewed December 2015 by Michael J. Fucci, DO Last Updated: 7/14/2016