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Atrial fibrillation

Medically reviewed by Last updated on Mar 8, 2024.


Atrial fibrillation (AFib) is an irregular and often very rapid heart rhythm. An irregular heart rhythm is called an arrhythmia. AFib can lead to blood clots in the heart. The condition also increases the risk of stroke, heart failure and other heart-related complications.

During atrial fibrillation, the heart's upper chambers — called the atria — beat chaotically and irregularly. They beat out of sync with the lower heart chambers, called the ventricles. For many people, AFib may have no symptoms. But AFib may cause a fast, pounding heartbeat, shortness of breath or light-headedness.

Episodes of atrial fibrillation may come and go, or they may be persistent. AFib itself usually isn't life-threatening. But it's a serious medical condition that needs proper treatment to prevent stroke.

Treatment for atrial fibrillation may include medicines, therapy to shock the heart back to a regular rhythm and procedures to block faulty heart signals.

A person with atrial fibrillation also may have a related heart rhythm problem called atrial flutter. The treatments for AFib and atrial flutter are similar.

Atrial fibrillation

In a typical heart, a tiny group of cells at the sinus node sends out an electrical signal. The signal travels through the heart's upper chambers to the atrioventricular (AV) node. The signal then passes into the lower heart chambers, causing them to squeeze and pump out blood. In atrial fibrillation, electrical signals fire from many locations in the upper chambers, causing them to beat chaotically. Since the AV node doesn't prevent all of these chaotic signals from entering the lower chambers, the heart beats faster and irregularly.


Symptoms of AFib may include:

Some people with atrial fibrillation (AFib) don't notice any symptoms.

Atrial fibrillation may be:

When to see a doctor

If you have symptoms of atrial fibrillation, make an appointment for a health checkup. You may be referred to a doctor trained in heart diseases, called a cardiologist.

If you have chest pain, seek immediate medical help. Chest pain could mean that you're having a heart attack.


To understand the causes of atrial fibrillation (AFib), it may be helpful to know how the heart typically beats.

The heart has four chambers:

Inside the upper right heart chamber is a group of cells called the sinus node. The sinus node makes the signals that starts each heartbeat.

The signals move across the upper heart chambers. Next, the signals arrive at a group of cells called the AV node, where they usually slow down. The signals then go to the lower heart chambers.

In a healthy heart, this signaling process usually goes smoothly. The resting heart rate is typically 60 to 100 beats a minute.

But in atrial fibrillation, the signals in the upper chambers of the heart are chaotic. As a result, the upper chambers tremble or shake. The AV node is flooded with signals trying to get through to the lower heart chambers. This causes a fast and irregular heart rhythm.

In people with AFib, the heart rate may range from 100 to 175 beats a minute.

Causes of atrial fibrillation

Problems with the heart's structure are the most common cause of atrial fibrillation (AFib).

Heart diseases and health problems that can cause AFib include:

Heart surgery or stress due to surgery or sickness may also cause AFib. Some people who have atrial fibrillation have no known heart disease or heart damage.

Lifestyle habits that can trigger an AFib episode may include:

Risk factors

Things that can increase the risk of atrial fibrillation (AFib) include:


Blood clots are a dangerous complication of atrial fibrillation (AFib). Blood clots can lead to stroke.

The risk of stroke from AFib increases as you grow older. Other health conditions also may increase the risk of a stroke due to AFib. These conditions include:

Blood thinners are commonly prescribed to prevent blood clots and strokes in people with atrial fibrillation.


Healthy lifestyle choices can reduce the risk of heart disease and may prevent atrial fibrillation (AFib). Here are some basic heart-healthy tips:


You may not know you have atrial fibrillation (AFib). The condition may be found when a health checkup is done for another reason.

To diagnose AFib, the health care provider examines you and asks questions about your medical history and symptoms. Tests may be done to look for conditions that can cause irregular heartbeats, such as heart disease or thyroid disease.


Tests to diagnose atrial fibrillation (AFib) may include:


The goals of atrial fibrillation treatment are to reset and control the heartbeat and prevent blood clots.

Treatment depends on:

Atrial fibrillation treatment may involve:

Together, you and your health care team discuss the best treatment option for you. It's important to follow your atrial fibrillation treatment plan. If AFib isn't well controlled, it may lead to other complications, including stroke and heart failure.


Treatment for atrial fibrillation may include medicines to do the following:

Medicines that may be used include:

Cardioversion therapy

If atrial fibrillation symptoms are bothersome or if this is the first AFib episode, a doctor may try to reset the heart rhythm using a procedure called cardioversion.

Cardioversion can be done in two ways:

Cardioversion is usually done in a hospital as a scheduled procedure. However, it may be done in emergency situations. If it's scheduled, a blood thinner such as warfarin (Jantoven) may need to be taken for a few weeks before the procedure. The medicine reduces the risk of blood clots and strokes.

After electrical cardioversion, medicines to control the heart rhythm may be needed for life to prevent future episodes of atrial fibrillation. Even with medicine, AFib could return.

Surgery or catheter procedures

If AFib doesn't get better with medicine or other treatments, a procedure called cardiac ablation may be necessary. Sometimes ablation is the first treatment.

Cardiac ablation often uses heat or cold energy to create tiny scars in the heart. The scars disrupt irregular heart signals and restore a typical heartbeat. A doctor inserts a flexible tube called a catheter through a blood vessel, usually in your groin, and into your heart. More than one catheter may be used. Sensors on the tip of the catheter apply the cold or heat energy.

Less commonly, ablation is done using a scalpel during open-heart surgery.

There are several types of cardiac ablation. The type used to treat atrial fibrillation depends on your specific symptoms, overall health and whether you're having another heart surgery.

Atrial fibrillation may return after cardiac ablation. If this happens, another ablation or heart treatment may be recommended. After cardiac ablation, lifelong blood thinners may be needed to prevent strokes.

If you have AFib but can't take blood thinners, you may need a procedure to seal a small sac in the left upper heart chamber. This sac, called an appendage, is where most AFib related clots form. This procedure is called left atrial appendage closure. A closure device is gently guided through a catheter to the sac. Once the device is in place, the catheter is removed. The device stays in permanently. Surgery to close the left atrial appendage also is an option for some people with AFib who are having another heart surgery.

AV node ablation

Atrioventricular (AV) node ablation uses heat energy, called radiofrequency energy, to destroy the area between the upper and lower heart chambers. This area is called the AV node. The heart's electrical signals can't pass through the damaged area. So this treatment blocks the faulty heart signals that cause atrial fibrillation (AFib). Once the AV node is destroyed, a pacemaker is needed to control the heart rhythm.

Lifestyle and home remedies

Following a heart-healthy lifestyle can help prevent or treat conditions that can lead to atrial fibrillation (AFib). The following changes are recommended to improve heart health:

It's also important to have regular health checkups. Tell your health care team if your AFib symptoms get worse.

Preparing for an appointment

If you have an irregular or pounding heartbeat, make an appointment for a health checkup. If AFib is found early, treatment may be easier, and it may work better. You may be referred to a doctor trained in heart diseases. This type of provider is called a cardiologist.

Here's some information to help you prepare for your appointment.

What you can do

For atrial fibrillation, some basic questions to ask your doctor include:

Don't hesitate to ask any other questions during your appointment.

What to expect from your doctor

During a health checkup, you are usually asked many questions. Being ready to answer them may save time to go over any details you want to spend more time on. You may be asked:

What you can do in the meantime

It's never too early to make heart-healthy lifestyle changes, such as quitting smoking, eating healthy foods and getting more exercise. A healthy lifestyle is the main protection against heart problems and heart-related complications.

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