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Most Common Irregular Heart Rhythm

Atrial fibrillation (AF) is an abnormal heart rhythm originating in the top two chambers of your heart, which are called the atria. AF is the most common irregular heart rhythm, afflicting 2.2 million Americans.

Atria Beats Out of Synch with Ventricles

During atrial fibrillation, the two top chambers (the atria) beat irregularly and chaotically and out of synch with the lower two chambers of the heart (the ventricles).

Effects Heart Ability to Pump Effectively

While the heart is in atrial fibrillation, it may not be able to pump effectively. This can lead to a reduction in cardiac output or a reduction in the heart's overall ability to pump blood out into the rest of the body.

Can Lead to Small Blood Clots

Without a strong, coordinated contraction, the atria don't empty as well as they should with each heartbeat. Some of the blood that normally would get pumped into the ventricles remains in the atrium. This can lead to the development of small blood clots in the atrium. If a clot develops, there is risk that it can then be pumped from the heart and lead to a stroke or a blood clot in another area of the body.

Can Lead to Complications If Untreated

AF typically is not life-threatening, but it can be an emergency issue as it can lead to complications if left untreated, including stroke and heart failure. Fortunately, there are a number of effective treatments for AF.

Types of Atrial Fibrillation

Paroxysmal Atrial Fibrillation

In some patients, AF comes and goes. This is called paroxysmal atrial fibrillation.

Chronic Atrial Fibrillation

In others, the condition occurs and remains all the time. This is called chronic atrial fibrillation.



Contact Information

Cardiovascular Medicine
Division of the CardioVascular Institute
Beth Israel Deaconess Medical Center
330 Brookline Avenue
Boston, MA 02215