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Atrial Fibrillation

What Is Atrial Fibrillation?

Approximately 2.7 million people in the United States have atrial fibrillation. It is the most common type of heart arrhythmia (irregular heartbeat) that can interrupt the normal flow of blood. This interruption means the condition puts you at risk for blood clots and stroke. Atrial fibrillation may be temporary, may come and go, or may be permanent. However, with regular medical care, you can live a normal, active life.

What Causes Atrial Fibrillation?

The heart contains four chambers: two atria and two ventricles. Atrial fibrillation occurs when these chambers do not work together as they should because of faulty electrical signaling. Normally, the atria and ventricles contract at the same speed. In atrial fibrillation, the atria and ventricles are out of synch because the atria contract very quickly and irregularly. Atrial fibrillation is often referred to as sick sinus syndrome because the sinoatrial (sinus) node in the right atrium controls the electrical impulses.

The cause of atrial fibrillation is not always known. Conditions that can cause damage to the heart and lead to atrial fibrillation include:

  • high blood pressure
  • congestive heart failure
  • coronary artery disease
  • heart valve disease
  • hypertrophic cardiomyopathy (the heart muscle becomes thick)
  • heart surgery
  • congenital heart defects (heart defects you are born with)
  • overactive thyroid gland
  • pericarditis (inflammation of the sac-like covering of the heart)
  • certain medications
  • binge drinking

Who Is at Risk for Atrial Fibrillation?

The following factors increase your risk of atrial fibrillation:

  • increased age (the older you are, the higher your risk for atrial fibrillation)
  • being white
  • being male
  • heart disease
  • structural heart defects
  • congenital heart defects
  • pericarditis
  • history of heart attacks
  • history of heart surgery
  • thyroid conditions
  • metabolic syndrome
  • obesity
  • lung disease
  • diabetes
  • drinking alcohol, especially binge drinking

The following might increase your risk:

  • a family history of atrial fibrillation
  • sleep apnea
  • high-dose steroid therapy

What Are the Symptoms of Atrial Fibrillation?

You might not experience any symptoms if you have atrial fibrillation; however, you might experience one or more of the following:

  • heart palpitations (feeling like your heart is skipping a beat, beating too fast or hard, or fluttering)
  • chest pain
  • fatigue
  • shortness of breath
  • weakness
  • lightheadedness
  • dizziness
  • fainting
  • confusion

How Is Atrial Fibrillation Diagnosed?

Your doctor may use one or more of the following tests to diagnose atrial fibrillation:

  • a physical exam to check your pulse, blood pressure, and lungs
  • electrocardiogram (EKG)—a test that records the electric impulses of your heart for a few seconds. If atrial fibrillation doesn’t occur during this test, your doctor may have you wear a portable EKG monitor. These include:
    -  Holter monitor—a small portable device you wear for 24 to 48 hours to monitor your heart
    -  event monitor—this device records your heart only at certain times or when you are having symptoms. It is worn for weeks or until atrial fibrillation symptoms occur.
  • echocardiogram—a noninvasive test that uses sound waves to produce a moving image of your heart
  • transesophageal echocardiogram—an invasive version of an echocardiogram that is performed by placing a probe in the esophagus
  • stress test—a test that monitors your heart during exercise
  • a chest X-ray to view your heart and lungs
  • blood tests to check for thyroid and metabolic conditions

How Is Atrial Fibrillation Treated?

You might not need treatment if you do not have symptoms, if you do not have other heart problems, or if the atrial fibrillation stops on its own. If you do require treatment, your doctor may recommend one or more of the following:


  • medications to normalize the speed of your heart contractions
  • medications to prevent atrial fibrillation
  • blood-thinning medications to prevent blood clots from forming


  • electrical cardioversion—a brief electrical shock resets the rhythm of your heart contractions
  • catheter ablation—a catheter delivers radio waves to the heart to destroy the abnormal tissue that sends out irregular impulses
  • atrioventricular (AV) node ablation—radio waves destroy the AV node, which connects the atria and ventricles. Then the atria can no longer send signals to the ventricles. A pacemaker is inserted to maintain a regular rhythm.


  • maze surgery—an open-heart surgery during which the surgeon makes small cuts or burns in the heart’s atria to create a "maze" of scars that will prevent abnormal electrical impulses from reaching other areas of the heart.

Your doctor might also recommend treatment for underlying health conditions, such as a thyroid problem or heart disease, that might be causing atrial fibrillation.


Most cases of atrial fibrillation can be managed or treated; however, atrial fibrillation tends to reoccur and get worse over time. The most common complications of atrial fibrillation are strokes and heart failure. If you have atrial fibrillation, you are five times more likely to have a stroke than people who do not have atrial fibrillation, according to the Centers for Disease Control and Prevention.


You can reduce your risk of atrial fibrillation by doing the following:

  • Eat a diet that is rich in fresh fruits and vegetables and low in saturated and trans fats.
  • Exercise regularly.
  • Maintain a healthy weight.
  • Avoid smoking.
  • Avoid drinking alcohol or only drink small amounts of alcohol occasionally.
  • Follow your doctor’s advice for treating any underlying health conditions that you have.

Content licensed from:

Written by: Rose Kivi and Marijane Leonard
Medically reviewed : George Krucik, MD

This feature is for informational purposes only and should not be used to replace the care and information received from your health care provider. Please consult a health care professional with any health concerns you may have.
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