What is atrial fibrillation?
Atrial fibrillation (say "AY-tree-uhl fih-bruh-LAY-shun") is the most common type of irregular heartbeat ( arrhythmia ).
Normally, the heart beats in a strong, steady rhythm. In atrial fibrillation, a problem with the heart's electrical system causes the two upper parts of the heart, the atria, to quiver, or fibrillate.
The quivering upsets the normal rhythm between the atria and the lower parts of the heart, the ventricles. And the ventricles may beat fast and without a regular rhythm.
This is dangerous because if the heartbeat isn't strong and steady, blood can collect, or pool, in the atria. And pooled blood is more likely to form clots. Clots can travel to the brain, block blood flow, and cause a stroke .
Atrial fibrillation can also lead to heart failure .
What causes atrial fibrillation?
Conditions that damage or strain the heart commonly cause atrial fibrillation. These include:
- High blood pressure.
- Coronary artery disease.
- Heart attack.
- Heart valve disease.
Other possible causes include:
- Other medical problems, such as heart failure, lung disease, pneumonia, or a high thyroid level .
- Heart surgery.
- Heavy alcohol use. This includes having more than 3 drinks a day over many years as well as drinking a large amount of alcohol at one time (binge drinking).
- Use of stimulants. These include caffeine, nicotine, medicines such as decongestants, and illegal drugs such as cocaine.
- Use of some prescription medicines, such as salbutamol or theophylline.
Sometimes doctors can't find the cause. Doctors call this lone atrial fibrillation.
What are the symptoms?
Symptoms may include:
- Feeling dizzy or light-headed.
- Feeling out of breath.
- Feeling weak and tired.
- Feeling like the heart is fluttering, racing, or pounding (palpitations).
- Feeling like the heart is beating unevenly.
- Having chest pain ( angina ).
Sometimes atrial fibrillation doesn't cause obvious symptoms.
If you have symptoms, see your doctor. Finding and treating atrial fibrillation right away can help you avoid serious problems.
How is atrial fibrillation diagnosed?
The doctor will ask questions about your past health, do a physical examination, and order tests.
The best way to find out if you have atrial fibrillation is to have an electrocardiogram (EKG or ECG). An EKG is a test that checks for problems with the heart's electrical activity.
You might also have lab tests and an echocardiogram . An echocardiogram can show how well your heart is pumping and whether your heart valves are damaged.
How is it treated?
Your treatment will depend on the cause of your atrial fibrillation, your symptoms, and your risk for stroke.
Medicines are an important part of treatment. They may include:
- Blood thinners or ASA to help prevent strokes.
- Rate-control medicines to keep your heart from beating too fast during atrial fibrillation.
- Rhythm-control medicines to help bring your heart rhythm back to normal.
Doctors sometimes use a procedure called cardioversion to try to get the heartbeat back to normal. This can be done using either medicine or a low-voltage electrical shock ( electrical cardioversion ).
If symptoms keep bothering you, ablation may help. It destroys small areas of the heart to create scar tissue. The scar tissue blocks or destroys the areas that are causing the abnormal heart rhythm.
What can you do at home for atrial fibrillation?
Atrial fibrillation is often the result of heart disease or damage. So making changes that improve the condition of your heart may also improve your overall health.
- Don't smoke. Avoid second-hand smoke too.
- Eat a heart-healthy diet with plenty of fish, fruits, vegetables, beans, high-fibre grains and breads, and olive oil.
- Get regular exercise on most, preferably all, days of the week. Your doctor can suggest a safe level of exercise for you.
- Control your cholesterol and blood pressure. If you have diabetes, keep your blood sugar in your target range.
- Manage your stress. Stress can damage your heart.
- Avoid caffeine, alcohol, and stimulants.
- Avoid getting sick from the flu. Get a flu shot every year.
Health Tools help you make wise health decisions or take action to improve your health.
|Decision Points focus on key medical care decisions that are important to many health problems.|
|Atrial Fibrillation: Should I Have Catheter Ablation?|
|Atrial Fibrillation: Should I Take an Anticoagulant to Prevent Stroke?|
|Atrial Fibrillation: Should I Try Electrical Cardioversion?|
|Atrial Fibrillation: Which Anticoagulant Should I Take to Prevent Stroke?|
|Actionsets are designed to help people take an active role in managing a health condition.|
|Blood Thinners Other Than Warfarin: Taking Them Safely|
|Warfarin: Taking Your Medicine Safely|
|Interactive tools are designed to help people determine health risks, ideal weight, target heart rate, and more.|
|Interactive Tool: What Is Your Risk for a Stroke if You Have Atrial Fibrillation?|
Frequently Asked Questions
Learning about atrial fibrillation:
Living with atrial fibrillation:
Atrial fibrillation is a problem with the heart's electrical system.
When something goes wrong with this system, it's usually because of other health problems that are causing wear and tear on the heart or making it hard for the heart to do its job. Sometimes it's because of lifestyle habits—such as smoking or heavy drinking—that are hard on the heart.
Problems that affect the heart's structure
Atrial fibrillation is often caused by a health problem that directly affects the heart, including:
- High blood pressure .
- Coronary artery disease .
- Heart attack .
- Heart valve disease .
Other health problems
Atrial fibrillation can also be caused by other health problems, including:
- Hyperthyroidism .
- Lung disease, such as COPD .
- Having heart surgery or other open-chest surgery.
- Taking certain prescription medicines, such as salbutamol or theophylline.
Atrial fibrillation caused by a condition that is treatable, such as pneumonia or hyperthyroidism, often goes away when that condition is treated.
In some cases, doctors cannot find the cause of atrial fibrillation. These cases are called lone atrial fibrillation. Lone atrial fibrillation occurs more often in people younger than 65. It often stops on its own. But it may need to be treated.
Atrial fibrillation is often discovered during routine medical checkups, because many people don't have symptoms. Others may notice an irregular pulse but don't have other symptoms.
Mild symptoms of atrial fibrillation may occur immediately. More serious problems may occur after the start of atrial fibrillation and over the course of several days. So it is important to identify symptoms and get treatment as soon as possible.
- Heart palpitations .
- Irregular pulse.
- Shortness of breath, especially during physical activity or emotional stress.
- Weakness, fatigue.
- Chest pain.
- Dizziness, confusion.
- Light-headedness or fainting ( syncope ).
Checking your pulse
Checking your pulse is important, because many people don't have symptoms of atrial fibrillation. Ask your doctor how often you should check your heartbeat. Once a month might be right for you.
If you notice that your heartbeat doesn't have a regular rhythm, talk to your doctor.
Paroxysmal atrial fibrillation
When atrial fibrillation comes on suddenly, lasts a short time, and goes away on its own, it is called paroxysmal atrial fibrillation . Typically, over time, episodes of paroxysmal atrial fibrillation come on more often and last longer.
Persistent atrial fibrillation
Over time, episodes of atrial fibrillation typically last longer and often don't go away on their own. If an episode lasts more than 7 days, this is called persistent atrial fibrillation. Treatment with medicine or cardioversion can restore a normal rhythm. This normal rhythm may last for several weeks or longer before atrial fibrillation happens again.
Permanent atrial fibrillation
Atrial fibrillation might start to happen all of the time. If atrial fibrillation has happened all of the time for at least 1 year, this is called permanent atrial fibrillation. Your treatments have not restored a normal rhythm, or you and your doctor have decided to stop trying to restore a normal rhythm.
What Increases Your Risk
A risk factor is anything that increases your chances of getting sick or having a problem. Risk factors for atrial fibrillation include:
- Age older than 60.
- Being white and male.
- Sleep apnea .
- A family history of atrial fibrillation.
- Certain other health problems can cause atrial fibrillation. For a list of these problems, see Cause.
You may have certain habits that increase your risk for atrial fibrillation because they can cause wear and tear on your heart. These lifestyle choices include:
- Long-term, heavy alcohol use, or drinking a large amount of alcohol at one time (binge drinking).
- Use of illegal drugs, such as cocaine or methamphetamines.
- Too much caffeine.
When to Call a Doctor
Call 911 or other emergency services immediately if you:
- Have symptoms of a heart attack , such as chest pain or pressure, shortness of breath, and nausea.
- Have symptoms of a stroke , such as sudden vision changes; trouble speaking; or numbness, tingling, weakness, or loss of movement in your face or an arm or a leg.
- Feel faint and have an irregular heartbeat.
If you see someone pass out, call 911 or other emergency services immediately.
Call your doctor if you have:
- An irregular heart rate.
- Heart palpitations .
- Periods of unexplained light-headedness, dizziness, or confusion.
- An episode of fainting or you come close to fainting for no apparent reason.
- Shortness of breath that gets worse with exercise.
If you take a blood thinner
If you take blood-thinning medicine, such as an anticoagulant or aspirin, watch for signs of bleeding.
Call 911 or other emergency services immediately if:
- You have a sudden, severe headache that is different from past headaches. (It may be a sign of bleeding in the brain.)
Call your doctor right away if you have any unusual bleeding, such as:
- Vaginal bleeding that is different (heavier, more frequent, at a different time of the month) than what you are used to.
- Bloody or black stools, or rectal bleeding.
- Bloody or pink urine.
Who to see
The following specialists can treat people who have severe symptoms:
Examinations and Tests
If your doctor suspects that you have atrial fibrillation that comes and goes, he or she may ask you to use a device to record your heart rhythm for a while. This is referred to by several names, including ambulatory electrocardiogram, ambulatory EKG, Holter monitoring, 24-hour EKG, and cardiac event monitoring. Your doctor might also use this device to check how well a medicine is working to control your heart rate.
Other tests your doctor may recommend include:
- Electrophysiology (EP) study . This test can help your doctor see if there is a problem with your heartbeat (heart rhythm) and find out how to fix it.
- Exercise electrocardiogram . Also called a stress test, this test will help your doctor see whether you have coronary artery disease.
- Echocardiogram . This test can show whether your heart valves are damaged, how well your heart is pumping, and whether you have heart failure or have had a heart attack.
- A blood test to check for hyperthyroidism .
- Prothrombin time and INR . If you take warfarin (such as Coumadin), you will need to have this type of blood test regularly to check how long it takes for your blood to clot.
It's hard to say exactly what your treatment for atrial fibrillation will be, because it depends so much on your symptoms and your risk for other health problems.
- Treatment to control your heart rate.
- Treatment to control your heart rhythm.
- Treatment to prevent stroke.
Treatment to control your heart rate
Rate-control medicines are used if your heart rate is too fast.
They usually do not return your heart to a normal rhythm—in other words, your heartbeat will still be irregular. But these medicines can keep your heart from beating at a dangerously fast rate. These medicines may also relieve symptoms.
Treatment to control your heart rhythm
Treatment to control your heart rhythm is done to try to stop atrial fibrillation and keep it from returning. It may also help your symptoms. Treatments include:
- Rhythm-control medicines, also called antiarrhythmics.
- Electrical cardioversion. This procedure uses a low-voltage electrical shock to return the heart to a normal rhythm.
- Catheter ablation. This might be done if your medicine hasn't brought back a normal heartbeat, or it's too hard to live with the side effects of medicine.
- Maze procedure. This is usually done during open-heart surgery. It creates scar tissue that blocks excess electrical impulses from travelling through your heart.
Treatment to prevent stroke
Atrial fibrillation is dangerous because if the heartbeat isn't strong and steady, blood can collect, or pool, in the atria . And pooled blood is more likely to form clots. Clots can travel through the bloodstream to the brain and other areas such as the legs. If clots travel to the brain, they can block blood flow and cause a stroke.
If you are at an average-to-high risk of having a stroke, your doctor may prescribe long-term use of an anticoagulant medicine, such as warfarin, to lower this risk.
If you are at low risk of having a stroke or you cannot take an anticoagulant, you may choose to take daily aspirin.
For more information, see Medications.
Do all you can to prevent heart disease, which is a cause of atrial fibrillation. Take steps toward a heart-healthy lifestyle.
- Manage your stress.
- Exercise regularly.
- Eat heart-healthy foods.
- Control your blood pressure.
- Lose extra weight.
- Don't smoke.
Living With Atrial Fibrillation
Many people are able to live full and active lives with atrial fibrillation. Most people don't have to change their daily activities.
Because atrial fibrillation is often the result of a heart condition, making changes to improve your heart condition will usually improve your overall health.
Make lifestyle changes
- Don't smoke. If you need help quitting, see the topic Quitting Smoking.
- Eat heart-healthy foods.
- Try an exercise program. Talk to your doctor about what type and level of exercise is safe for you.
- Control your stress. Treatments like yoga, biofeedback, and meditation may help.
- Don't use alcohol, caffeine, or stimulants, such as methamphetamines or cocaine.
- Control your weight. For more information, see the topic Weight Management.
For more information, see:
Prevent other health problems
- If needed, take medicines to control your cholesterol and blood pressure.
- Talk with your doctor or pharmacist before taking any new medicine. Tell your doctor all of the medicines you take. Some prescription and non-prescription medicine can interact with your heart medicines. Some non-prescription medicines, especially cold and herbal remedies, contain stimulants that can trigger atrial fibrillation.
- Get a flu vaccine every year.
- Know the signs of sleep apnea . Tell your doctor if you have symptoms such as snoring and feeling sleepy during the day. Many people with atrial fibrillation also have this condition.
Take medicines safely
When you take an anticoagulant (also called a blood thinner), you need to take extra steps to avoid bleeding problems, such as preventing falls and injuries. If you take warfarin, you also get regular blood tests and watch how much vitamin K you eat or drink.
If you have atrial fibrillation, you will likely take a medicine to help prevent a stroke . You may also take a medicine that controls your heart rate or your heart rhythm.
Medicine to prevent a stroke
Anticoagulant medicines, also called blood thinners, are recommended for most people with atrial fibrillation who are at average to high risk of stroke.
Anticoagulant choices include:
- Warfarin (Coumadin).
Anticoagulants other than warfarin.
- Apixaban (Eliquis)
- Dabigatran (Pradaxa)
- Rivaroxaban (Xarelto)
If you are age 55 or older and have atrial fibrillation, you can find your risk of having a stroke in the next 5 years using this Interactive Tool: What Is Your Risk for a Stroke if You Have Atrial Fibrillation?
For help deciding about an anticoagulant, see:
Aspirin and other antiplatelet medicines
If you are at low risk of stroke or cannot take anticoagulants, your doctor may recommend that you take aspirin. It doesn't work as well as anticoagulant medicines in preventing clots, but it doesn't have as many side effects.
Your doctor may have you take other antiplatelet medicines, such as clopidogrel (Plavix), along with aspirin or instead of aspirin. When aspirin and clopidogrel are used together, they may reduce the risk for stroke more than aspirin alone. This combination of clopidogrel and aspirin doesn't work as well as an anticoagulant to prevent clots. Also, this combination is more likely to cause bleeding than aspirin alone.
Medicine to control your heart rate
Rate-control medicines are used if your heart rate is too fast. The medicine slows your heart rate. Your heart rate may not need to be very low. A heart rate of 110 beats per minute may be enough to help you. 1
These medicines include:
Rate-control medicines may relieve symptoms caused by the fast heart rate. But these medicines may not relieve other symptoms caused by atrial fibrillation.
Medicine to control your heart rhythm
Rhythm-control medicines (also known as antiarrhythmics) help return the heart to its normal rhythm and keep atrial fibrillation from returning. They may help relieve symptoms caused by an irregular heart rate.
If medicine doesn't help atrial fibrillation, a procedure called catheter ablation may be done. It destroys the heart tissue that causes atrial fibrillation and that keeps atrial fibrillation going after it starts.
For help deciding whether catheter ablation is a good choice for you, see:
Pacemakers are sometimes needed by people who have atrial fibrillation.
Other Places To Get Help
CardioSmart is an online program that provides patient education and support from the American College of Cardiology. The goal of CardioSmart is to engage, inform, and empower patients to participate in their own care and partner with their cardiologists. The website contains information about heart problems, living with heart disease, and preventing heart disease. It also provides patient-centered news and can help you find a cardiologist. The website has a Health and Wellness Center with information about diet and exercise, managing medicines, and working with your doctor.
The American College of Cardiology is a nonprofit medical society whose members include many types of health professionals, including doctors, nurses, and surgeons.
|Heart and Stroke Foundation of Canada|
|222 Queen Street|
|Ottawa, ON K1P 5V9|
The Heart and Stroke Foundation of Canada works to improve the health of Canadians by preventing and reducing disability and death from heart disease and stroke through research, health promotion, and advocacy.
|Heart Rhythm Society|
|1400 K Street NW|
|Washington, DC 20005|
The Heart Rhythm Society provides information for patients and the public about heart rhythm problems. The website includes a section that focuses on patient information. This information includes causes, prevention, tests, treatment, and patient stories about heart rhythm problems. You can use the Find a Specialist section of the website to search for a heart rhythm specialist practicing in your area.
|U.S. National Heart, Lung, and Blood Institute (NHLBI)|
|P.O. Box 30105|
|Bethesda, MD 20824-0105|
The U.S. National Heart, Lung, and Blood Institute (NHLBI) information center offers information and publications about preventing and treating:
- Van Gelder IC, et al. (2010). Lenient versus strict rate control in patients with atrial fibrillation. New England Journal of Medicine, 362(15): 1363–1373.
Other Works Consulted
- Calkins H, et al. (2012). 2012 HRS/EHRA/ECAS expert consensus statement on catheter and surgical ablation of atrial fibrillation: Recommendations for patient selection, procedural techniques, patient management and follow-up, definitions, endpoints, and research trial design. A report of the Heart Rhythm Society (HRS) Task Force on Catheter and Surgical Ablation of Atrial Fibrillation. Heart Rhythm, 9(4): 632–696.e21.
- Fuster V, et al. (2011). 2011 ACCF/AHA/HRS focused update incorporated into the ACC/AHA/ESC 2006 guidelines for the management of patients with atrial fibrillation: A report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. Circulation, 123(10): e269–e367.
- Lane DA, et al. (2011). Atrial fibrillation (chronic), search date June 2011. BMJ Clinical Evidence. Available online: http://www.clinicalevidence.com.
- Lip GYH, Apostolakis S (2011). Atrial fibrillation (acute onset), search date April 2010. BMJ Clinical Evidence. Available online: http://www.clinicalevidence.com.
- Miller JM, Zipes DP (2012). Therapy for cardiac arrhythmias. In RO Bonow et al., eds., Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine, 9th ed., vol. 1, pp. 710–744. Philadelphia: Saunders.
- Prystowsky EN, et al. (2011). Atrial fibrillation, atrial flutter, and atrial tachycardia. In V Fuster et al., eds., Hurst's The Heart, 13th ed., vol. 1, pp. 963–986. New York: McGraw-Hill.
- Roy D, et al. (2008). Rhythm control versus rate control for atrial fibrillation and heart failure. New England Journal of Medicine, 358(25): 2667–2677.
- Shea JB, Sears SF (2008). A patient's guide to living with atrial fibrillation. Circulation, 117(20): e340–e343.
- Sherman DG, et al. (2005). Occurrence and characteristics of stroke events in the atrial fibrillation follow-up investigation of sinus rhythm management (AFFIRM) study. Archives of Internal Medicine, 165(10): 1185–1191.
- Skanes AC, et al. (2012). Focused 2012 update of the Canadian Cardiovascular Society Atrial Fibrillation Guidelines: Recommendations for stroke prevention and rate/rhythm control. Canadian Journal of Cardiology, 28(2): 125–136. Also available online: http://www.ccs.ca/guidelines/cc_library_e.aspx.
- Treatment of atrial fibrillation (2010). Treatment Guidelines From The Medical Letter, 8(97): 65–70.
- Van Gelder IC, et al. (2010). Lenient versus strict rate control in patients with atrial fibrillation. New England Journal of Medicine, 362(15): 1363–1373.
- Wang TJ, et al. (2003). A risk score for predicting stroke or death in individuals with new-onset atrial fibrillation in the community: The Framingham heart study. JAMA, 290(8): 1049–1056.
- You JJ, et al. (2012). Antithrombotic therapy for atrial fibrillation: Antithrombotic therapy and prevention of thrombosis, 9th ed.—American College of Chest Physicians evidence-based clinical practice guidelines. Chest, 141(2, Suppl): e531S–e575S.
|Primary Medical Reviewer||Rakesh K. Pai, MD, FACC - Cardiology, Electrophysiology|
|Primary Medical Reviewer||Brian D. O'Brien, MD - Internal Medicine|
|Specialist Medical Reviewer||John M. Miller, MD, FACC - Cardiology, Electrophysiology|
|Last Revised||August 23, 2013|
Last Revised: August 23, 2013
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