Atrial fibrillation is a type of arrhythmia. There are four main types of atrial fibrillation—paroxysmal, persistent, long-term persistent, and permanent atrial fibrillation. The type of atrial fibrillation that you have depends on how often atrial fibrillation occurs and how it responds to treatment.
You may experience a brief event—a paroxysm—of atrial fibrillation. It may pass without symptoms, or you may feel it strongly. It usually stops in less than 24 hours but may last up to a week. Paroxysmal atrial fibrillation can happen repeatedly.
You may need treatment or your symptoms may go away on their own. When this kind of atrial fibrillation alternates with a heartbeat that is slower than normal, it is called tachybrady syndrome.
Persistent atrial fibrillation is a condition in which the abnormal heart rhythm lasts for more than a week. It may ultimately stop on its own but probably will need treatment.
With this condition, the abnormal heart rhythms last for more than a year without going away.
Sometimes atrial fibrillation does not get better, even when you have tried several times to restore a normal heart rhythm with medicines or other treatments. At this point, your atrial fibrillation is considered permanent.
Changes to the heart’s tissue and to its electrical signals most often cause atrial fibrillation. To understand atrial fibrillation, it helps to know how the heart works. When the heart’s tissue or signaling is damaged, the regular pumping of the heart muscle becomes fast and irregular. Most often, damage to the heart is the result of other conditions such as high blood pressure and ischemic heart disease. Other factors can also raise your risk of atrial fibrillation.
Usually the cells of the heart fire and contract together. However, when aging, heart disease, infection, genetics, or other factors change heart tissue, that pattern breaks down. This can happen because of fibrosis, inflammation, a thinning or thickening of the heart walls, lack of blood flow to the heart, or an abnormal buildup of proteins, cells, or minerals in heart tissue.
Usually, a trigger heartbeat sets off atrial fibrillation. Electrical signals from this trigger may then cause the heart to beat slower or faster than usual because of changes in heart tissue. Sometimes, the signals create an atypical loop, telling the heart to contract over and over. This can create the fast, chaotic beating that defines atrial fibrillation.
Variations in the heart’s electrical signaling can be due to differences in heart anatomy, premature or extra heartbeats, normal heart rate adjustments, patches of faster or slower tissue, and repeated stimulation of certain tissue patches.
Age, family history and genetics, lifestyle, heart disease or other medical conditions, race, sex, and a history of surgery can all raise your risk of developing the structural and electrical anomalies that cause atrial fibrillation. Even in a healthy heart, a fast or slow heart rate—from exercising or sleeping, for example—can trigger atrial fibrillation.
The risk of atrial fibrillation increases as you age, especially after age 65. Atrial fibrillation is rare in children, but it does occur, especially in boys and in children who have obesity.
If someone in your family has had atrial fibrillation, you have a higher risk of developing atrial fibrillation, too. Scientists have found some genes with mutations that raise the risk of atrial fibrillation. Some of these genes influence fetal organ development or heart cell ion channels. Sometimes these genetic patterns are also linked to heart disease. Some genetic factors may raise the risk of atrial fibrillation in combination with such factors as age, weight, or sex.
Some lifestyle habits can raise or lower your risk of atrial fibrillation, including the following:
Many other medical conditions can increase your risk of atrial fibrillation, especially heart problems. As you age, having more than one condition may increase your risk. Conditions that raise the risk of atrial fibrillation include:
In the United States, atrial fibrillation is more common among whites than among African Americans, Hispanic Americans, or Asian Americans. Although people of European ancestry are more likely to develop the condition, African Americans with atrial fibrillation are more likely to have complications such as stroke, heart failure, or ischemic heart disease.
You may be at risk for atrial fibrillation in the early days and weeks after surgery of the heart, lungs, or esophagus. Surgery to correct a congenital heart defect can also raise the risk of atrial fibrillation. This can happen years after a childhood surgery or when you have surgery as an adult to correct a lifelong condition.
Typically doctors screen for atrial fibrillation only when you have risk factors. However, your doctor may check for signs of atrial fibrillation as part of your regular medical care. Screening tests include checking your pulse or recording your heart’s electrical activity. Your doctor may recommend healthy lifestyle changes to help you lower your risk of developing atrial fibrillation.
Screening may be part of your regular care if you are 65 or older or if you have other risk factors.
To help you lower your risk of atrial fibrillation, your doctor may recommend certain heart-healthy lifestyle changes, including aiming for a healthy weight, being physically active, controlling your blood sugar, limiting alcohol, lowering your blood pressure, managing stress, and quitting smoking.
In addition, some illegal drugs, such as cocaine, can trigger atrial fibrillation or make it worse. Ask your doctor for help avoiding these triggers to prevent arrhythmia.
If you are having heart surgery, your medical team will monitor you. To prevent arrhythmia, your doctor may recommend antiarrhythmic medicine or treatment to maintain or supplement electrolyte levels during or after the procedure.
You may or may not notice atrial fibrillation. It often occurs with no signs or symptoms. If you do have symptoms, you may notice something that occurs only occasionally. Or, your symptoms may be frequent or serious. If you have heart disease that is worsening, you may notice more symptoms of atrial fibrillation. If your atrial fibrillation is undetected or left untreated, serious and even life-threatening complications can arise. They include stroke and heart failure.
The most common symptom of atrial fibrillation is fatigue. Other signs and symptoms include:
Keep track of when and how often your symptoms occur, what you feel, and whether these things change over time. They are all important clues for your doctor.
When it is undetected or untreated, atrial fibrillation can lead to serious complications. This is especially significant for African Americans. Even though whites have atrial fibrillation at higher rates, research has found that many of its complications—including stroke, heart disease, and heart failure—are more common among African Americans. Some complications of atrial fibrillation include:
A doctor will diagnose atrial fibrillation based on your medical and family history, a physical exam, the results from an electrocardiogram (EKG), and possibly other tests and procedures. If you have atrial fibrillation, your doctor will also look for any disease that may be causing it and assess your risk of developing dangerous blood clots. This will help him or her plan the best way to treat you.
To help diagnose atrial fibrillation, your doctor will ask about your eating and physical activity habits, family history, and other risk factors for atrial fibrillation and heart disease. Your doctor may ask whether you have any other signs or symptoms. This information can help your doctor determine whether you have complications or other conditions that may be causing you to have atrial fibrillation.
Your doctor will do a complete examination of your heart and lungs, including:
To diagnose atrial fibrillation, your doctor will likely do an EKG first to record your heart’s electrical activity. Data from a pacemaker or implanted defibrillator may also be helpful. If the diagnosis is unclear from the EKG or your doctor would like more information, your doctor may order additional testing:
Your doctor may order other tests to record abnormal heart rhythms that happen under specific conditions or outside of the clinic, confirm whether you have atrial fibrillation or another arrhythmia, and figure out which treatment is best. These tests may include:
Atrial fibrillation is treated with lifestyle changes, medicines, and procedures, including surgery, to help prevent blood clots, slow your heart beat, or restore your heart’s normal rhythm.
Your doctor may recommend adopting heart-healthy lifestyle changes, such as the following:
Your doctor may consider treating your atrial fibrillation with medicines to slow your heart rate or to make your heart’s rhythm more even:
Your doctor may recommend treatments for an underlying cause or to reduce atrial fibrillation risk factors. For example, he or she may prescribe medicines to treat overweight and obesity, an overactive thyroid, lower high blood pressure, manage high blood cholesterol, control or prevent diabetes, or help you quit smoking.
Your doctor may recommend a procedure, especially if lifestyle changes and medicine alone did not improve your symptoms. Typically, your doctor will consider a surgical procedure to treat your atrial fibrillation only if you will be having surgery to treat some other heart condition.
If you have been diagnosed with atrial fibrillation, it is important that you continue your treatment. Follow-up care can help your doctor check your condition and talk to you about how to prevent repeat events and what to do in an emergency. Sometimes, atrial fibrillation may go back to a normal heart rhythm without treatment.
How often you need to see your doctor for follow-up care will depend on your symptoms and treatment.
Return to Treatment to review possible treatment options for your atrial fibrillation.
Regular visits to the clinic give your doctor a chance to see how well medicines are controlling your atrial fibrillation, monitor your ongoing risks of clotting or bleeding, and see how well you are healing from any procedures. Your doctor may also ask you to wear a heart rhythm monitor and send data in between visits to see how well your treatment is working and to detect any repeat events.
To help prevent a repeat episode of atrial fibrillation, your doctor may recommend the following:
Atrial fibrillation can lead to serious complications such as sudden cardiac arrest and stroke. Risks of treatment with blood thinners include severe bleeding in the brain. If you suspect any of the following in you or someone else, call 9-1-1 right away:
Atrial fibrillation research is a major focus of NHLBI funding and the source of findings with important consequences for clinical care. Learn about the following ways the NHLBI continues to translate current research into improved health for people with atrial fibrillation. Research on this topic is part of the NHLBI’s broader commitment to advancing heart and vascular disease scientific discovery.
Learn about some of the pioneering research contributions we have made over the years that have improved clinical care.
In support of our mission, we are committed to advancing atrial fibrillation research in part through the following ways.
Learn about exciting research areas that the NHLBI is exploring about atrial fibrillation.
We lead or sponsor many studies on atrial fibrillation. See if you or someone you know is eligible to participate in our clinical trials.
After reading our Atrial Fibrillation Health Topic, you may be interested in additional information found in the following resources.