Atrial Fibrillation

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

About Atrial Fib

Atrial fib is a common heart rhythm disorder that causes your heart to beat irregularly. It happens when the upper chambers of your heart (the atria), contract very quickly and irregularly (fibrillation). This causes blood to pool in your atria instead of getting pumped into the lower chambers of your heart (the ventricles).

When blood pools in your atria, blood clots are more likely to form. If a piece of a blood clot leaves your heart and travels to your brain, it may become stuck in an artery (blood vessel). This results in a stroke.

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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 of atrial fib are:

  • Having high blood pressure for a long time
  • A heart attack
  • Heart failure
  • Heart valve disease
  • Heart surgery
  • Chronic lung disease

Less often, atrial fib can be caused by other types of surgery. Atrial fib during surgery is usually temporary.

Atrial fib can also be caused by other things, such as:

  • Drinking too much alcohol or binge drinking
  • Hyperthyroidism (having an overactive thyroid)
  • Medications that increase your heart rate, such as theophylline (a medication in some inhalers, used to treat asthma) or caffeine
  • Sleep apnea
  • An infection anywhere in your body
  • Chemotherapy

If the cause of atrial fib is unknown, it’s called lone atrial fibrillation.

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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 (an unusually fast, strong, or irregular heartbeat)
  • Mild chest discomfort
  • Heart racing
  • Lightheadedness
  • Mild shortness of breath
  • Mild fatigue

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

  • Difficulty breathing
  • Shortness of breath
  • Fainting or feeling as though you’re going to faint
  • Confusion
  • Chest discomfort
  • Fatigue
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Treatment for Atrial Fib

There are several ways to treat and prevent abnormal beating of the heart. These include:

  • 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®)
  • Electrical cardioversion (KAR-de-o-VER-shun), which is an electrical shock that’s given to your heart. It can be used to restore your heart’s normal rhythm. It’s used most often when medications don’t improve symptoms.
  • Radiofrequency ablation, which is a procedure to destroy the tiny areas in your heart that are causing atrial fib. 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.
  • A pacemaker, which is a small device placed under your skin near your heart that prevents your heart from beating too slowly. Some medications for atrial fib can cause your heart to beat too slowly. If you need a pacemaker, your doctor will tell you more about it.
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About Medications to Lower Stroke Risk

Medications are used to help reduce stroke risk in people with atrial fib. They thin your 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’re the usual treatment for 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:

  • Having a stroke in the past
  • Having congestive heart failure (CHF)
  • Age
  • Uncontrolled high blood pressure
  • Having blood clots in the past
  • Diabetes
  • Vascular disease (disease affecting the blood vessels)
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If you’d like to learn more about atrial fib, visit the American Heart Association’s Atrial Fibrillation web page at

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