Please note: This information was current at the time of publication but now may be out of date. This handout provides a general overview and may not apply to everyone. 

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Am Fam Physician. 2016;94(6):online

See related article on atrial fibrillation

What is atrial fibrillation?

Atrial fibrillation (fih-brih-LAY-shun) is caused by a problem with your heart's electrical system. It causes the upper chamber of your heart to shake, and not pump blood well. Sometimes a clot can form in this chamber, and if that clot breaks free it can cause a stroke.

What are the symptoms?

Your heartbeat may feel fast and uneven. You may also feel weak, tired, or short of breath. You may find it hard to exercise. Some people may feel faint or have chest pain.

What puts me at risk?

You are at risk if you have high blood pressure; a history of heart disease (heart attack, heart failure, or abnormal heart valves); lung disease; an overactive thyroid; or sleep apnea. You are also at risk if you drink a lot of alcohol or use stimulant drugs.

How is it diagnosed?

Your doctor will record your heartbeat using electrocardiography (also called ECG or EKG) and will order a test to see how your heart is pumping blood. He or she will also order some blood tests and a chest x-ray. Some patients may need to see a doctor who specializes in heart conditions. You may need to stay in the hospital if your symptoms are severe or if you need close monitoring or more tests.

How is it treated?

Most patients will take medicine to slow down the heart so that it can pump better. Your doctor may also recommend trying to restore a normal heart rate using medicines or an electrical procedure called cardioversion. Finally, your doctor will recommend steps to prevent a stroke. This often includes using medicine to thin your blood. Thinning your blood can reduce the risk of stroke, but it also increases your risk of bleeding. It is important that you discuss the risks and benefits with your doctor. Several blood-thinning medicines are available. Your doctor will help you choose which one is best for you.

The treatment of atrial fibrillation can be challenging. Tell your doctor about any side effects from the medicine. Do not stop taking the medicine without checking with your doctor. Stopping the medicine may not be safe, and it may increase the risk of harmful events.

How can I prevent it?

The best way to prevent atrial fibrillation is to lower your risk of heart disease. You can do this by lowering high blood pressure and high cholesterol, controlling diabetes, limiting alcohol intake (no more than two drinks for men and one drink for women per day), and exercising. Follow your doctor's instructions for taking medicine, and keep regular follow-up visits with your doctor.

Where can I get more information?

Your doctor

AAFP's Patient Information Resource

American Heart Association

National Institutes of Health

National Library of Medicine

This handout was adapted with permission from Gutierrez C, Blanchard DG. Atrial fibrillation: diagnosis and treatment [patient handout]. Am Fam Physician. 2011;83(1):71–72. Accessed July 5, 2016.

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