Home > Patients & Visitors > Health Library > 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.
Conditions that damage or strain the heart commonly cause atrial fibrillation. These include:
Other possible causes include:
Symptoms may include:
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.
The doctor will ask questions about your past health, do a physical exam, 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.
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:
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 you have symptoms that are hard to live with, 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.
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.
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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.
Atrial fibrillation is often caused by a health problem that directly affects the heart, including:
Atrial fibrillation can also be caused by other health problems, including:
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.
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.
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. If you have atrial fibrillation but have trouble feeling if your heart beat is irregular, you can buy a low-priced stethoscope to listen to your heart.
If you notice that your heartbeat doesn't have a regular rhythm, talk to your doctor.
Atrial fibrillation is called paroxysmal if episodes last 7 days or less. The episodes may go away on their own or they go away after treatment.
Typically, over time, episodes of paroxysmal atrial fibrillation come on more often and last longer.
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. If an episode lasts for more than 12 months, it is called long-standing persistent atrial fibrillation.
Atrial fibrillation is called permanent if you and your doctor have decided to not restore a normal heart rhythm. Although it is called permanent, you can change your mind later and try treatments to restore a normal heart rhythm.
A risk factor is anything that increases your chances of getting sick or having a problem. Risk factors for atrial fibrillation include:
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:
Call 911 or other emergency services immediately if you:
If you see someone pass out, call 911 or other emergency services immediately.
Call your doctor if you have:
If you take blood-thinning medicine, such as an anticoagulant or aspirin, watch for signs of bleeding.
Call your doctor right away if you have any unusual bleeding, such as:
The following health professionals can detect, diagnose and, in some cases, treat atrial fibrillation:
The following specialists can treat people who have severe symptoms:
An electrocardiogram (EKG, ECG) is the best and simplest way to find out whether you have atrial fibrillation. It is usually done along with a medical history and physical exam.
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.
Other tests your doctor may recommend include:
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.
Treatments are aimed at helping you feel better and preventing future problems, especially stroke and heart failure. There are three main types of treatment:
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 is done to try to stop atrial fibrillation and keep it from returning. It may also help your symptoms. Treatments include:
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 cause a stroke.
Your doctor can help you know your risk of a stroke based on your age and health. This information can help you and your doctor decide how to lower your risk.
If you are at an average-to-high risk of having a stroke, your doctor may prescribe long-term use of an anticoagulant medicine 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 or to not take a blood thinning medicine.
For more information, see Medications.
An implanted device (such as Watchman) is a new way to try to lower the risk of stroke. The device may prevent blood clots from moving out of the heart and causing a stroke. The device is placed inside of the heart with a procedure that uses catheters in blood vessels. This device might be used in some people who cannot take an anticoagulant long-term.
For more information on this device, see Other Treatments.
Do all you can to prevent heart disease, which is a cause of atrial fibrillation. Take steps toward a heart-healthy lifestyle.
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.
For more information, see:
When you take a blood thinning medicine, 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 slows your heart rate or controls your heart rhythm.
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:
For help deciding about an anticoagulant, see:
If you are at low risk of having a stroke or cannot take anticoagulants, you may choose to take daily aspirin or to not take a blood thinning medicine.
Aspirin doesn't work as well as anticoagulant medicines to prevent a stroke. But aspirin might be less likely to cause bleeding problems.
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.
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.
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.
Electrical cardioversion uses a low-voltage electrical shock to return an irregular heartbeat to a normal rhythm.
Catheter ablation is a minimally invasive procedure. 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:
AV node ablation is another type of catheter ablation. It does not stop atrial fibrillation but it can relieve symptoms.
An implanted device (such as Watchman) is a newer way to try to lower the risk of stroke caused by atrial fibrillation. Doctors call the device a left atrial appendage closure device. This means that the device closes a very small part of the left atrium (a chamber of the heart) where blood clots might form. The device may prevent these blood clots from moving out of the heart and causing a stroke.
The device is placed inside of the heart with a procedure that uses catheters in blood vessels. This procedure is available at a small number of hospitals. The device is not right for everyone. It might be used for a person who cannot take an anticoagulant long-term. Research shows that the device may work as well as the anticoagulant called warfarin to prevent stroke. It is not known how the device compares to other anticoagulants. There is a chance of harm from the procedure and the device, including bleeding and blood clots. Doctors do not know the long-term benefits and risks of the device. You and your doctor can decide if the device is right for you.
Reddy VY, et al. (2017). 5-year outcomes after left atrial appendage closure from the PREVAIL and PROTECT AF trials. Journal of the American College of Cardiology, 70(24): 2964-2975. DOI: 10.1016/j.jacc.2017.10.021. Accessed April 13, 2018.
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.
January CT, et al. (2014). 2014 AHA/ACC/HRS Guideline for the management of patients with atrial fibrillation: A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and the Heart Rhythm Society. Circulation, published online March 28, 2014. DOI: 10.1161/?CIR.0000000000000041. Accessed April 18, 2014.
Noelck N, et al. (2016). Effectiveness of left atrial appendage exclusion procedures to reduce the risk of stroke: A systematic review of the evidence. Circulation Cardiovascular Quality and Outcomes, 9(4): 395–405. DOI: 10.1161/CIRCOUTCOMES.115.002539. Accessed July 19, 2016.
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.
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.
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.
Current as ofJuly 22, 2018
Author: Healthwise StaffMedical Review: Rakesh K. Pai, MD - Cardiology, ElectrophysiologyE. Gregory Thompson, MD - Internal MedicineMartin J. Gabica, MD - Family MedicineAdam Husney, MD - Family MedicineJohn M. Miller, MD, FACC - Cardiology, Electrophysiology
Current as of:
July 22, 2018
Medical Review:Rakesh K. Pai, MD - Cardiology, Electrophysiology & E. Gregory Thompson, MD - Internal Medicine & Martin J. Gabica, MD - Family Medicine & Adam Husney, MD - Family Medicine & John M. Miller, MD, FACC - Cardiology, Electrophysiology
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