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Understanding Atrial Fibrillation

Under normal circumstances, the human heart pumps to a strong and steady beat—in fact, more than 100,000 heartbeats each day! But if you have atrial fibrillation, or AFib, the heart doesn’t always beat or keep pace the way it should. Many people with AFib say they can feel their heart racing, fluttering or skipping beats. 

AFib is the most common heart rhythm disorder (arrhythmia). A major concern with AFib is that it also makes blood clots in the heart that can travel and cause strokes or block flow to other critical organs. In fact, people with this condition are five times more likely to have a stroke than people without the condition. It can also lead to heart failure. But finding and treating AFib early on can help you avoid these problems.

Take the time to learn about AFib and what you can do to manage it.

What is atrial fibrillation?

Your heart’s electrical system tells your heart when to contract and pump blood to the rest of your body. With AFib, these electrical impulses don’t work the way they should, short-circuiting in a sense. As a result, the heart beats too quickly and irregularly. 

AFib is sometimes called a quivering heart. That’s because the two upper parts of the heart (called the atria) quiver. When this happens, the normal communication between the upper and lower chambers of the heart is disrupted and becomes very disorganized. Because of this, many people with AFib feel zapped of energy fairly quickly or notice being out of breath simply walking up one flight of stairs. That’s because you may not be getting enough oxygen; the heart isn’t able to squeeze enough nutrient-rich blood out to the body. 

There are 3 types of AFib:

  • Paroxysmal – comes and goes and generally stops on its own
  • Persistent – lasts more than a week and can become permanent
  • Permanent – the heart’s normal rhythm can’t be restored 

Some cases of AFib are due to a heart valve problem, while some are not.

If you have AFib, you’re not alone. It’s the most common type of irregular heartbeat, affecting more than 3 million Americans. If untreated, it can lead to blood clots, stroke and heart failure.

Because your heart beat is out of sync, blood can collect in the chambers of the heart. When this happens, blood clots can form and can travel to the brain causing a stroke. Strokes related to AFib tend to be more severe and deadly.

What puts you at risk for AFib

Several factors make AFib more likely.

  • Older age, although it can happen at any age
  • Conditions that place added strain on the heart, including:
  • Other illnesses such as obesity, sleep apnea or hyperthyroidism
  • Family history   
  • Drinking too much alcohol (routinely having 3 or more drinks a day or binge drinking) 

Episodes of AFib are often triggered by certain activities. These may include: 

  • Heavy alcohol use
  • Too much caffeine or other stimulants
  • Periods of severe stress
    • the stress of the body fighting infection
    • the stress of recent surgery

Pay attention to what might make symptoms of AFib worse, so that you can share this information with your health care team.

How it feels

Some people with AFib don’t have any symptoms. Those who do may report:

  • Heart palpitation -- a thumping or racing heart, fluttering or skipping beats
  • Feeling unusually tired or fatigued
  • Unexplained shortness of breath
  • Dizziness or fainting spells
  • Chest pain (angina)

Detecting an abnormal heart rhythm

To find out if you have AFib, your doctor will likely rely on a combination of:

  • Your medical history and physical exam
  • Results from an electrocardiogram (EKG or ECG) -- a test that records your heart’s electrical activity and shows deviations  
  • Other methods to monitor your heart’s rhythm, if needed. Additional tests may include:
    • Wearing a Holter monitor, essentially a portable EKG to measure and record your heart's activity for 24 hours
    • Using an event monitor that, with a push of a button, allows you to record what is happening when you feel symptoms such as chest pain, dizziness or palpitations. Electrodes are placed on your chest and are connected by wire leads to the recording device. You generally will wear this for 1 month.
    • Having an echocardiogram, an ultrasound that takes pictures of the heart and measures the chambers and how well it is pumping 

Sometimes, people are diagnosed with AFib after going to the hospital emergency department and are “in AFib.”


The good news is that with the right treatment, you can live a good life with AFib. But you need to be in tune with your heart and body. Untreated, atrial fibrillation can lead to blood clots, stroke and other heart-related problems, including heart failure. 

Your treatment will likely depend on:

  • Your age
  • Your symptoms and the frequency of episodes
  • Whether your heart rate is under control
  • Your risk for stroke (see the CHADS2VASC score to determine your risk and need for anticoagulation)
  • Other medical conditions, including if you already have heart disease 

Treatment of AFib focuses on lifestyle changes and either rate control or rhythm control. Therapies to prevent blood clots and stroke are also important. 

Lifestyle changes may include:

  • Eating a heart-healthy diet full of fresh fruits and vegetables, fiber-rich foods, lean meats and fish and unsaturated fats like olive oil
  • Limiting alcohol and caffeine
  • Exercising regularly – aim to get 30 minutes of physical activity most days
  • Managing stress levels
  • Not smoking
  • Taking your medication(s) as directed and managing other conditions 

In addition to lifestyle changes, treatments often include medications and/or procedures.


Medications are used to:

  • Prevent clots from forming or to dissolve an existing clot
  • Restore your heart’s rate or rhythm 

Medications to prevent or treat blood clots and stroke include:

Talk with your doctor about which blood thinner is right for you. Keep in mind that if you take a blood thinner, you must be very cautious about falls and other accidents that might cause bleeding. There are medicines or antidotes that can reverse the blood-thinning power of warfarin, but no reversal agents exist yet for the newer medications. 

There may also be dietary restrictions. For example, foods like spinach, kale and other vegetables are rich in vitamin K, which can disrupt the way warfarin works. That’s why you have to be careful to consume the same amount every day if you take warfarin. You also need to have your blood checked frequently when taking this medicine (called your INR/PT).  

Rate controlling medications Heart rhythm controlling medications

Medical procedures

  • Electrical cardioversion – uses low-voltage electrical shock applied to the chest with paddles to restore a normal rhythm
  • Catheter-based ablation – a tube is inserted into a vein in the leg and threaded to the heart to fix the faulty electrical signals
  • Surgical maze – small scar lines are made on the heart, creating a “maze” to prevent or redirect the abnormal beats from controlling the 
heart. This is done through open heart surgery.
  • Pacemakers or atrial defibrillators – implantable devices that help restore and maintain regular heart rhythm

Knowing the signs of a stroke 

If you live with AFib, it’s critical that you know the warning signs of stroke so that you can act fast. Call 9-1-1 right away if you have any sudden:

  • Numbness or weakness in your face, arms or leg, especially on one side of the body
  • Trouble walking or loss of balance or coordination
  • Trouble seeing out of one or both eyes
  • Confusion, trouble speaking or understanding
  • Severe headache

Be sure other people in your life are aware of these signs as well.

Did You Know?

  • A healthy heart beats between 60 and 100 times per minute. With AFib, it beats much faster – as many as 175 times per minute!
  • 1 in 5 strokes in the U.S. is due to AFib
  • Men are more likely to develop AFib, but women who have it are more likely to die earlier in life
  • Remember, many people with AFib may not have symptoms

Talking with your care team

It can be unsettling to live with AFib, especially if you can physically feel your heart beating unevenly. Be sure to share any concerns with your care team, especially how to manage your risk for stroke. 

Here are some questions you may want to ask:

  1. What type of AFib do I have? Will I have it forever?
  2. What’s the difference between medications that control heart rhythm and those that control heart rate? Which one might be better for me and why?
  3. How serious is my risk for stroke?
  4. Which blood thinner is best for me?
  5. How else can I lower my risk of stroke?
  6. Are there changes I can make in my everyday life to prevent episodes of AFib?
  7. What type and how much exercise should I be getting?
  8. At what point should I consider a device or surgical procedure?

Helpful resources

To learn more about AFib, click here. To learn more about stroke, click here.  

In addition to the resources on, you can find out more by visiting:

American Heart Association

National Heart, Lung and Blood Institute

National Stroke Association 

Stop Afib

Published: Sept. 2015
Medical Reviewer: Daniel Alyeshmerni, Chief Cardiology Fellow, University of Michigan Health System


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