What Is Atrial Fibrillation?

Press your hand against your chest. Those little thumps you feel are your heart pumping, moving blood into and out of its chambers and through the rest of your body.

Normally, the top part of your heart (the atria) squeezes first, then the bottom part (the ventricles). The timing of these contractions is what moves the blood. But for more than 2 million Americans, the electrical signals that control this system are off-kilter. Instead of working together, the atria do their own thing. This fast, fluttering heartbeat, what doctors call arrhythmia, is atrial fibrillation, or AFib.

More than annoying, it can be serious. Because your blood isn't moving well, you're at greater risk for heart failure. That's when your heart can't keep up with the needs of your body. Blood can also pool inside your heart and form clots. If one gets stuck in your brain, you can have a stroke.

Who Gets It?

Anyone can have AFib, but it's more common in people who are ages 60 and older.

Other heart problems can make it more likely:

People with certain medical conditions have a greater chance, too:

Certain medicines (including adenosine, digitalis, and theophylline) can raise the risk of AFib.

Sometimes, it's linked to:

  • Heavy alcohol, caffeine, or drug use
  • Infections
  • Genetics


When your heart is in AFib, you might feel:

  • Like your heart is racing or fluttering in your chest (palpitations)
  • Fatigued or weak
  • Dizzy or lightheaded
  • Chest pain or pressure
  • Short of breath

If you have these symptoms, call your doctor and make an appointment as soon as possible. If they last more than 24 hours, go to the hospital.

Sometimes it doesn't cause any symptoms, though. If you're at risk, talk to your doctor about your chances for having AFib, and get regular checkups.


The main thing your doctor wants to see is the electrical activity in your heart. An electrocardiogram (EKG) uses small, sticky sensors placed on your chest to record what's happening.


Your doctor may want you to wear a Holter monitor for a few days while you go about your regular activities. It's like a mobile EKG that continuously records what's going on with your heart, so your doctor can look for signs of an arrhythmia.

If your AFib symptoms come and go, you may need a different kind of monitor for a longer time.

Your doctor might ask for other tests and imaging, including:

  • Blood tests to check your thyroid, liver, and kidneys
  • A chest X-ray, if you might have lung disease
  • An echocardiogram, which uses sound waves to make a video of your heart working
  • Special X-rays, called CT, that make a 3-D picture of your heart
  • An MRI, which uses magnets and radio waves to create snapshots and videos of your heart
  • An exercise stress test


Depending on how severe your symptoms are, you doctor may recommend medications, surgical procedures, or even a pacemaker to get and keep your heart in a normal rhythm.

Your doctor can give you medicine to:

  • Slow your heart rate and ease the strength of contractions (beta-blockers and calcium channel blockers)
  • Bring your heart's rhythm back to normal (sodium and potassium channel blockers)
  • Prevent blood clots ("blood thinners" or anticoagulants, and antiplatelets)

When medications don't work, doctors can try electrical cardioversionto reset your heart's rhythm. This uses pads stuck on your chest to send an electric shock to your heart. You won't feel it because you'll be asleep under general anesthesia.

Your doctor can also stop the short-circuiting in your heart by burning off the tissue on the surface of your heart that's causing the problem, or creating scar tissue that doesn't pass the offbeat signals. Usually, he'll get to your heart through a small tube placed in a blood vessel, and then use a laser, radio waves, or extreme cold. These procedures are called ablation.

If you're having open heart surgery for another reason, your doctor might do the maze procedure, which is similar to ablation.

A pacemakercan help keep your heart rate steady. People who take medicine to lower their heart rate may need one as a backup. You'll have minor surgery to put the small device under your skin. It runs on batteries and sends little electrical bursts to your heart when it beats too slowly.


Healthy Lifestyle

You can protect your heart by the choices you make in your daily life, too.

Eat a healthy diet that includes plenty of fresh vegetables and fruits, along with whole grains and lean protein. Limit alcohol and caffeine. Quit smoking.

Exercise is good for you and your heart. It helps keep your muscles strong, your blood moving, and your weight in check. It even helps your sleep. Talk to your doctor about the best activities for you, so you don't overdo it.

Check the labels on over-the-counter products, such as cold medications. They could have ingredients that will speed up your heart rate.

WebMD Medical Reference Reviewed by James Beckerman, MD, FACC on July 12, 2017



News release, FDA.

American Heart Association: "Atrial Fibrillation."

Cleveland Clinic: "What is Atrial Fibrillation?"

American Academy of Family Physicians: "Atrial Fibrillation."

The University of Chicago Medical Center: "Surgical Treatment for Atrial Fibrillation."

Shea, J. Circulation, May 20, 2008.

Ferri, F. Ferri's Clinical Advisor 2011, 1st ed., Mosby Elsevier, 2010.

Bonow, R. Braunwald's Heart Disease - A Textbook of Cardiovascular Medicine, 9th ed. Saunders Elsevier, 2011.

Task Force for the Management of Atrial Fibrillation. European Heart Journal, October 2010.

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