What Is AFib ? | Atrial Fibrillation| MedStar Health

Expert care for this common type of irregular heartbeat

Atrial fibrillation, or AFib, is the most common type of arrhythmia (abnormal heart rhythm), in which the heart’s two upper chambers do not beat in sync with the two lower chambers. Our patients sometimes describe it as “feeling like there’s a fish jumping in my chest.”

A normal heart rate for adults ranges from 60 to 100 beats a minute. If you have atrial fibrillation, your heart may beat much faster, up to 100 to 175 times a minute, or much slower.

Although AFib by itself is not life-threatening, it can increase your risk of stroke and heart failure if not treated. In fact, it causes about 20 percent of all strokes because blood pools in the heart chambers and clots form.

AFib is the most common type of arrhythmia, affecting more than 5 million people in the U.S.—a figure that keeps growing as the population ages. Our Cardiac Electrophysiology Program is a national leader in performing ablation procedures, such as cryoablation procedures, for AFib management. We also have the mid-Atlantic’s most experienced facility using the WATCHMAN™ device, which can prevent blood clots from forming and causing strokes in patients.

Atrial Fibrillation

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What are the types of AFib?

There are four types of AFib:

  • Paroxysmal: An irregular heartbeat that lasts less than 7 days, usually less than 24 hours, and has recurred at least twice.
  • Persistent: An irregular heartbeat that lasts longer than 7 days, but the abnormal rhythm can be stopped with treatment.
  • Permanent: An irregular heartbeat that lasts longer than 1 year and does not respond to treatment if it has been attempted.
  • Lone: An irregular heartbeat that is paroxysmal or persistent and occurs without another form of heart disease.

What are the symptoms of AFib?

Many people with atrial fibrillation do not feel any symptoms. However, you may experience:

  • Palpitations, or sensations of a racing heart or fluttering in your chest

  • Fatigue
  • Weakness
  • Shortness of breath
  • Dizziness or lightheadedness
  • Confusion or anxiety
  • Sweating
  • Chest pain (angina); if you are experiencing severe chest pain, call 911 immediately

  • Fluid retention and swelling
  • Heart failure

What are the causes and risk factors of AFib?

The most common causes of AFib are abnormalities or damage to the heart’s structure.

Certain factors can increase your risk of developing AFib, including:


Cardiac Catheterization

Cardiac catheterization is a minimally invasive way to diagnose and treat a variety of heart and vascular conditions by guiding thin, flexible tubes called catheters through blood vessels to problem areas.

Chest X-ray

Chest X-rays use a small dose of radiation to create pictures of the structures inside the chest, including the lungs, heart, and chest wall.


An echocardiogram uses high-frequency sound waves to create images of your heart.

Electrocardiogram (ECG)

An electrocardiogram, also known as an ECG, measures the heart’s electrical activity.

Electrophysiology Testing

Electrophysiology testing is used to evaluate the cause and location of an abnormal heartbeat (known as an arrhythmia).

Event Monitors

An event monitor is a small device that records the heart’s electrical activity. It’s similar to an electrocardiogram, but where an electrocardiogram takes place over a few minutes, an event monitor measures heart rhythms over a much longer time.

Holter Monitors

A Holter monitor is a small device that records the heart’s electrical activity. It’s similar to an electrocardiogram, but whereas an electrocardiogram records over a few minutes, a Holter monitor records over the course of a day or two.

Loop Recorder

A loop recorder is a device that’s implanted underneath the skin of your chest to record your heart rhythm for up to 3 years.

Stress Tests

Stress tests are used to assess how your heart works during physical activity. There are several types of stress tests, including treadmill or bike stress tests, nuclear stress tests, stress echocardiograms, and chemically induced stress tests.

Tilt Table Test

Tilt table testing allows your doctor to determine the cause of explained fainting while monitoring changes in your blood pressure and heart rate while tilted at different angles.


One of the main goals when treating atrial fibrillation is to limit symptoms. This may be achieved through heart rate control or efforts to reset or control the heart’s rhythm. This often can be done with a combined approach of lifestyle modification, treatment of other conditions, medication, or more advanced procedures.

Cardiac Ablation

Cardiac ablation uses heat or cold to destroy heart tissue causing abnormal heart rhythms known as arrhythmias.

Catheter Ablation for Atrial Fibrillation

Catheter ablation is a minimally invasive procedure that uses heat or cold to destroy heart tissue causing atrial fibrillation, a type of abnormal heart rhythm.

Heart Surgery for Atrial Fibrillation (Maze)

A surgical maze procedure treats atrial fibrillation (AFib) by creating a pattern, or maze, of scar tissue in the heart to disrupt faulty electrical signals causing your abnormal heart rhythm.


A pacemaker is a device that helps control various types of heart rhythm disorders.

Radiofrequency Ablation for Atrial Fibrillation

Radiofrequency ablation uses extreme heat to destroy heart tissue causing an abnormal heart rhythm known as atrial fibrillation.

Ask MedStar Heart & Vascular Institute

Have general questions for our heart and vascular program? Email us at AskMHVI@medstar.net. If you have clinically-specific questions, please contact your physician’s office.