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Information from Your Family Doctor

Atrial Fibrillation


Am Fam Physician. 2011 Jan 1;83(1):71-72.

  See related article on atrial fibrillation

What is atrial fibrillation?

There is an electrical signal in your heart that causes it to beat and pump blood to your body. If the signal is jumbled or irregular, it causes the upper chambers (atria) of your heart to tremble rapidly. This is called fibrillation (fih-brih-LA-shun). It can cause many problems, including the following:

  • Blood can pool in parts of your heart, so there is less blood available to be pumped.

  • Blood can clot when it pools. If the clot gets free, it can travel to your brain and cause a stroke.

  • The trembling in the upper chambers can cause the lower chambers to get off beat. This makes it difficult for your heart to pump blood through your body.

What are the symptoms?

You may feel a fast, uneven heart beat. You may also feel weak, tired, or short of breath. You may find it difficult 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; or an overactive thyroid. You may also be at risk if you drink a lot of alcohol.

How is it diagnosed?

Your doctor will order a test to take a picture of your heart's electrical signal, as well as a picture that shows how your heart is working. You may also need blood tests and possibly a chest x-ray. You may need to stay in the hospital. Some patients may need to see a doctor who specializes in heart conditions.

How is it treated?

There are three main parts to treating atrial fibrillation.

  • Slow down the heart so that it can pump better. This can be done with medicine taken orally or through an IV.

  • Restore the heart's normal beat with medicines or an electrical procedure called cardioversion. During this procedure, a brief electrical current is sent through your chest to fix the electrical activity in your heart. This is done while you are “asleep” and under anesthesia so you do not feel anything.

  • Take steps to prevent a stroke. Your doctor may prescribe medicine to thin your blood. The two main blood thinners are aspirin and warfarin (brand name: Coumadin). Warfarin works better than aspirin, but it is more likely to cause bleeding. If your doctor prescribes warfarin, you will need to have frequent blood tests. Your doctor will help you choose the medicine that is right for you.

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, and getting physical activity. Follow your doctor's instructions for taking medicine, and tell him or her if you are having side effects. Regular follow-up visits with your doctor are important.

This handout is provided to you by your family doctor and the American Academy of Family Physicians. Other health-related information is available from the AAFP online at

This information provides a general overview and may not apply to everyone. Talk to your family doctor to find out if this information applies to you and to get more information on this subject.


Copyright © 2011 by the American Academy of Family Physicians.
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