What is Atrial Fibrillation?

Updated:Jan 5,2016

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 (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.

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)

Can AFfib lead to other problems?

Yes. You can live with AFib, but it can lead to other medical problems including:

  • Stroke
  • Heart failure
  • Chronic fatigue
  • Additional heart rhythm problems
  • Inconsistent blood supply

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 blood clots can form.

What can be done to correct it?

Treatment options may include one or more of the following:

  • Medicines, such as beta blockers or antiarrhythmics, to help return your heart rate to a normal rhythm
  • Medicines such as digitalis, calcium channel blockers or amiodarone, to help slow your heart rate.
  • Blood thinners to keep blood clots from forming.
  • Electrical cardioversion (an electric shock) to change the beat of your heart back to normal.
  • Surgery, a pacemaker or other procedures may be needed.
Your treatment will depend on the underlying cause of your AFib and your level of disability.

How can I lower my risk of stroke?

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  warfarin and aspirin. Anticoagulants include warfarin and three other more recently FDA approved drugs referred to as novel oral anticoagulants or NOACs — dabigatran, rivoraxaban and apixaban.

  • Always tell your doctor, dentist and pharmacist if you take any of these medications.
  • If you have any unusual bleeding or bruising or other problems, tell your doctor right away.
How can I learn more?
  1. Call 1-800-AHA-USA1 (1-800-242-8721), or visit heart.org to learn more about heart disease and stroke.
  2. Sign up to get Heart Insight, a free magazine for heart patients and their families, at heartinsight.org.
  3. Connect with others sharing similar journeys with heart disease and stroke by joining our Support Network at heart.org/supportnetwork.
We have many other fact sheets 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.

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?

©2015, American Heart Association 

Multi-language Fact Sheet Topics

Heart-related Conditions
What is Angina?
What is an Arrhythmia?
What Is Atrial Fibrillation?
What Do My Cholesterol Levels Mean?
How Can I Improve My Cholesterol?
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 Artery Disease?

Stroke, Recovery and Caregiving
Hemorrhagic Stroke
Ischemic Stroke
Stroke, TIA and Warning Signs
What Are the Warning Signs of Stroke?
Stroke Risk Factors
Lifestyle Changes to Prevent Stroke
Stroke Diagnosis
Complications After Stroke
Changes Caused by Stroke
Emotional Changes After Stroke
Feeling Tired After a Stroke
Stroke and Aphasia
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?
How Do I Manage My Medicines?
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?
How Can I Cook Healthfully?
Why Should I Limit Sodium?
How Do I Understand "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?