This information describes the causes, symptoms, and treatment of atrial fibrillation (A-treal fi-bri-LA-shun), also called atrial fib or a-fib.

What is atrial fib?

Atrial fib is a common heart rhythm disorder that causes the heart to beat irregularly. It occurs when the upper chambers of the heart (the atria), contract very fast and irregularly (fibrillation). In atrial fib the blood pools in the atria instead of getting pumped into the lower chambers of the heart (the ventricles). The pooling of blood may lead to the development of blood clots. If a piece of blood clot from the atria leaves the heart and travels to the brain, it may become lodged in an artery. This results in a stroke.

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What are the causes of atrial fib?

The risk of atrial fib increases as people get older. It happens more often in people who have other heart diseases. The most common causes are:

  • Long history of high blood pressure
  • A heart attack
  • Heart failure
  • Heart valve disease
  • Heart surgery and less often, other types of surgery (atrial fib during surgery is usually temporary)
  • A variety of chronic lung diseases

It can also be brought on by other events, such as:

  • Alcohol and binge drinking
  • Hyperthyroidism, or an overactive thyroid
  • Medications that stimulate the heart, such as theophylline or caffeine
  • Sleep apnea
  • Infection
  • Chemotherapy

In some people, the cause is unknown. When this occurs, it is called lone atrial fibrillation.

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What are the symptoms of atrial fib?

Not everyone is aware they have atrial fib. Some people have no symptoms at all, while others have many symptoms that tell them something is wrong. Mild symptoms include:

  • Palpitations or irregular beating of the heart
  • Mild chest discomfort
  • Heart racing
  • Lightheadedness
  • Mild shortness of breath
  • Mild fatigue

As the ventricles of the heart beat faster or more irregularly, symptoms may be more severe and include:

  • Difficulty breathing
  • Shortness of breath with exertion
  • Fainting or near fainting
  • Confusion
  • Chest discomfort
  • Fatigue
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How is atrial fib treated?

There are several ways to treat and prevent abnormal beating of the heart, including:

  • Medications to slow down the fast heart rate, such as:
    • Beta blockers (atenolol, metoprolol, propanolol)
    • Digoxin (Lanoxin®)
    • Amiodarone (Cordarone®)
    • Calcium channel blockers (verapamil, diltiazem)
    • Sotalol (Betapace®)
    • Procainamide
    • Quinidine
    • Propafenone (Rythmol®)
  • Electrical cardioversion (KAR-de-o-VER-shun) can be used to restore the heart’s normal rhythm. This is an electrical shock that is given to the heart. It is used most often when medications don’t improve symptoms.
  • Radiofrequency ablation can be effective when medications and electrical cardioversion don’t work. If you need an ablation, your doctor will tell you more about it. You will need to have this done in another hospital.
  • Pacemakers can be placed to prevent the heart from beating too slowly, which can be caused by medications that treat atrial fib.
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How can I lower my risk of stroke if I have atrial fib?

Medications are used to help reduce stroke risk in people with atrial fib. They thin the blood and make it less likely to clot. Examples include:

  • Blood thinners, also called anticoagulants, such as warfarin (Coumadin®), enoxaparin (Lovenox®), and rivaroxaban (Xarelto®). They are most often used with people who are at high risk for stroke.
  • Aspirin, which is the usual treatment for people who are at a low risk for stroke.

Your doctor will determine the best treatment for you based on your risk factors for developing a stroke. Risk factors include:

  • History of stroke
  • History of congestive heart failure (CHF)
  • Age
  • Uncontrolled high blood pressure
  • Anticoagulation history
  • Diabetes
  • Vascular disease
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