What is Atrial Fibrillation?

Updated:Feb 8,2013

Normally, your heart contracts and relaxes to a regular beat. Certain cells in your heart make electric signals that cause the heart to contract and pump blood. These electrical signals show up on an electrocardiogram (ECG) recording. Your doctor can read your ECG to find out if the electric signals are normal.

In atrial fibrillation (AF or AFib), the heart's two small upper chambers (atria) don’t beat the way they should in a forceful, and rhythmic way. Instead of beating in a normal pattern, the atria beat irregularly and too fast, quivering like a bowl of gelatin. It’s important for the heart to pump properly, so your body gets the oxygen and food it needs. You can live with AFib, but it can lead to other rhythm problems, chronic fatigue, heart failure and — worst of all — stroke. You’ll need a doctor to help you control the problem.

How do I know I have atrial fibrillation?

Here are some of the symptoms you may have:

  • Irregular and rapid heartbeat
  • Heart palpitations or rapid thumping inside the chest
  • Dizziness, sweating and chest pain or pressure
  • Shortness of breath or anxiety
  • Tiring more easily when exercising
  • Fainting (syncope)

What can correct it?

Sometimes AFib can be corrected with an electric shock. This shock may change the beat of your heart back to normal.

  • You may take medicines, such as beta blockers or antiarrhythmics, to help return your heart rate to a normal rhythm
  • You may take medicines such as digitalis, calcium channel blockers or amiodarone to help slow your heart rate.
  • You may need surgery, a pacemaker or other procedures.
Your treatment will depend on the underlying cause of your AFib and your level of disability.

How can I lower my risk of stroke?

The risk of stroke is about five times higher in people with AFib. This is because with AFib blood can pool in the atria and form blood clots.

To reduce your stroke risk, your doctor may prescribe you drugs to keep blood clots from forming. Two examples are anticoagulants and antiplatelets such as aspirin and warfarin. More recently a drug called dagibitran has been approved, and may also be prescribed .

  • Always tell your doctor, dentist and pharmacist if you take aspirin, warfarin or dabigitran.
  • If you have any unusual bleeding or bruising or other problems, tell your doctor right away.

How can I learn more?

  1. Talk to your doctor, nurse or other healthcare professionals. If you have heart disease or have had a stroke, members of your family also may be at higher risk. It’s very important for them to make changes now to lower their risk.
  2. Call 1-800-AHA-USA1 (1-800-242-8721), or visit heart.org to learn more about heart disease.
  3. For information on stroke, call 1-888-4-STROKE (1-888-478-7653) or visit us online at StrokeAssociation.org.

We have many other fact sheets and educational booklets to help you make healthier choices to reduce your risk, manage disease or care for a loved one. Visit heart.org/answersbyheart to learn more.

Knowledge is power, so Learn and Live!

Do you have questions or comments for your doctor or nurse?

Take a few minutes to write your own questions for the next time you see your healthcare provider. For example:

What should my pulse be?

How do I take my pulse?

©2012, American Heart Association 

Multi-language Fact Sheet Topics

Heart-related Conditions
What is Angina?
What is an Arrhythmia?
What Is Atrial Fibrillation?
How Can I Lower High Cholesterol?
What Do My Cholesterol Levels Mean?
What Are High Blood Cholesterol and Triglycerides?
What Is High Blood Pressure?
How Can I Reduce High Blood Pressure?
High Blood Pressure and Stroke
What Is Diabetes and How Can I Manage It?
How Can I Live With Heart Failure?
What Is Heart Failure?
What Is a Heart Attack?
How Will I Recover From My Heart Attack?
What Are the Warning Signs of Heart Attack?
What Are Heart Disease and Stroke?
What is Metabolic Syndrome?
What is Peripheral Vascular Disease?

Stroke, Recovery and Caregiving
Hemorrhagic Stroke
Ischemic Stroke
What Are the Warning Signs of Stroke?
Lifestyle Changes to Prevent Stroke
Stroke Diagnosis
Changes Caused by Stroke
Emotional Changes After Stroke
Feeling Tired After a Stroke
Stroke and Rehabilitation
Stroke Family Caregivers
How Should I Care for Myself as a Caregiver?

Treatment, Tests and Procedures
What is Cholesterol-Lowering Medicine?
What is High Blood Pressure Medicine?
What Are Anticoagulants and Antiplatelet Agents?
What Is an Implantable Cardioverter Defibrillator?
What Is a Pacemaker?
What Is Coronary Angioplasty?
What is a Stent?
What is Coronary Bypass Surgery?
What is a Coronary Angiogram?
How Can I Recover From Heart Surgery?
What is Carotid Endarterectomy?

Healthy Lifestyle and Risk Reduction
How Can I Manage My Weight?
How Can Physical Activity Become a Way of Life?
Why Should I Be Physically Active?
How Do I Follow a Healthy Diet?
Why Should I Limit Sodium?
How Do I Read "Nutrition Facts" Labels?
How Can I Quit Smoking?
How Can I Manage Stress?
How Can I Make My Lifestyle Healthier?
How Can I Monitor My Cholesterol, Blood Pressure and Weight?