This information describes the causes, symptoms, and treatment of atrial fibrillation (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 if the upper chambers (atria) of your heart beat faster than the lower chambers (ventricles). The atria quiver instead of beat. Blood is not pumped completely out of them. This leads to pooling of the blood in the atria and 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.

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 external events such as:

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

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

What are the symptoms of atrial fib?

Not all patients are aware they have atrial fib. Some patients have no symptoms. Others have multiple 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 or 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

How is atrial fib treated?

Several approaches are used to treat and prevent abnormal beating of the heart.

  • Medications are used to slow down the fast heart rate, including:
    • Beta blockers (atenolol, metoprolol, propanolol)
    • Digoxin (Lanoxin®)
    • Amiodarone (Cordarone®)
    • Calcium channel blockers (verapamil, diltiazem)
    • Sotalol (Betapace®)
    • Procainamide
    • Quinidine
    • Propafenone (Rythmol®)
  • Electrical cardioversion can be used to restore heart rhythm. This is an electrical shock that is given to the heart. This is used only when medications don't improve symptoms.
  • Radiofrequency ablation can be effective in some patients when medications and electrical cardioversion don't work. If you need this, 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.

How can I lower my risk of stroke if I have atrial fib?

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

  • Warfarin (Coumadin®) and dabigatran (Pradaxa®), which are anticoagulants (blood thinners). They are most often used when patients are at high risk for stroke.
  • Aspirin, which is the usual treatment for patients 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. These factors include:

  • History of prior stroke
  • History of congestive heart failure
  • Age
  • Uncontrolled high blood pressure
  • Anticoagulation history