Overview of Atrial Fibrillation

Atrial fibrillation is the most common type of irregular heartbeat (arrhythmia). It is caused by an abnormal rhythm in the upper chambers of the heart (the atria).

Normally, an electrical pulse travels through the heart about 60 to 100 times per minute while you're at rest. With atrial fibrillation, the electrical pulses come too fast. The pulses in the upper chambers then compete for a chance to travel to the lower chambers of the heart. The result is a rapid, irregular heartbeat.

In a healthy heart, electrical impulses move smoothly from the SA node through the heart. The heart beats evenly and regularly.

With atrial fibrillation, the electrical impulses come too fast. Some of them circulate in the atria rather than passing through the heart. 

Atrial Fibrillation in Depth

Learn more about atrial fibrillation from Intermountain's Patient Education Library:

Diagnostic Tests for Patients with Atrial Fibrillation

Your doctor may order several tests that measure and record the electrical activity of your heart. These tests may be done before your appointment, so that the doctor can review them with you as soon as possible.

    • Electrocardiogram (EKG or ECG)

      This test records the electrical activity of your heart. An EKG provides information about your heart's rate and rhythm. It also diagnoses ischemia (lack of oxygen to the heart muscle), heart attacks, and a variety of other heart conditions.

    • Holter Monitor

      This device records the electrical activity of your heart as you go about your daily activities. You will wear the Holter monitor for 24 to 48 hours.

    • Ambulatory Telemetry and Event Monitors

      This device is similar to a Holter monitor. It records your electrical activity for up to 30 days. It also allows you to push a button to indicate when you are experiencing heart symptoms.

    • Electrophysiology Study

      During this procedure, a heart rhythm doctor delivers small electrical impulses to the heart to help evaluate your heart rhythm. Your doctor will do this in the catheterization "cath" lab at the hospital.

    • Genetic Testing

      If atrial fibrillation runs in your family, it is important to tell your doctor. Our Genetic Heart Disease Program can help you and your family members explore genetic testing and treatment options.

    Treatments for Atrial Fibrillation

    Your doctor will discuss your treatment options with you. Possible treatments for atrial fibrillation include:

    • Medications

      Heart rhythm medications, also called antiarrhythmics, control irregular heartbeats — and maintain a normal heart rate and rhythm. Patients with atrial fibrillation may also need to take blood thinning medications to help prevent blood clots and reduce the risk of stroke.

    • Ablation

      Ablation is a technique typically used to treat abnormal heart rates and rhythms (arrhythmias). It involves ablating (destroying) a very small, targeted area of the heart muscle.

    • Watchman Left Atrial Appendage Closure

      You may be eligible for a catheter-based procedure called the Watchman left atrial appendage closure, or “the Watchman procedure”. This procedure can reduce your risk of stroke and eliminate the need to take blood thinning medications. It does not, however, treat your atrial fibrillation. You may need to continue other heart medications or treatments.

    • MAZE Procedure (Heart Rhythm Surgery)

      The MAZE procedure is an open heart surgical procedure that treats atrial fibrillation by creating therapeutic scars on the heart muscle.

    • GALAXY Procedure (Heart Rhythm Surgery)

      The GALAXY procedure is a revolutionary, minimally invasive operation developed at Intermountain Heart Institute. The procedure is designed to treat atrial fibrillation without the use of the heart-lung machine and with smaller, less painful incisions.

Learn about Atrial Fibrillation

What is Atrial Fibrillation?

What is atrial fibrillation? Normally, the heart pumps in a well-timed fashion. The two upper chambers (atria) contract first followed by the two lower chambers (ventricles). This coordinated pumping ...

The Clinical Cardiac Electrophysiologist

A clinical cardiac electrophysiologist, or cardiac EP, is a doctor who treats rhythm problems of the heart. A cardiac EP is a type of cardiologist. A cardiologist is a doctor who has had three or more...

Atrial Flutter

There are many types of abnormal heart rhythms, or arrhythmias. Symptoms range from mild to life-threatening. Atrial flutter is a common type of arrhythmia. Atrial flutter involves the upper chambers ...