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Atrial Fibrillation

Last Updated: Mar 1, 2019


Atrial fibrillation (AF) is a fast, irregular heart rhythm in which the two upper chambers of the heart (the atria) quiver rapidly (fibrillate) instead of pumping at a normal steady pace.

Types of AF

  1. Paroxysmal atrial fibrillation. Paroxysmal AF is an intermittent form of AF that comes and goes on its own.
  2. Persistent atrial fibrillation. Persistent AF is a longer lasting type of AF, which can be corrected with treatment.
  3. Permanent atrial fibrillation. Permanent AF does not go away and cannot be stopped with treatment.

Heart functions

The heart’s natural pacemaker, the sinoatrial node (SA node), is a collection of tiny cells that send electrical signals to produce heartbeats. Normally, the SA node generates electrical signals that trigger well-timed, organized contractions of the upper chambers (atria) and the lower chambers (ventricles). However, in AF, the electrical signals are fast and chaotic. The atria quiver rapidly and irregularly, so blood pools in the atria instead of being pumped properly to the ventricles. In some patients with AF, the ventricles also pump poorly in a condition known as heart failure.


Underlying heart disease is by far the most common cause of AF. Numerous conditions leading to AF include the following:


During atrial fibrillation, some people do not experience any symptoms at all. Other individuals are affected by symptoms ranging from mild to severe. Symptoms include:



Usually a physical exam will reveal irregular heart sounds and an abnormal pulse rate. When atrial fibrillation is suspected, further testing is required to confirm the diagnosis.


Some people with AF spontaneously convert back to a normal rhythm without treatment. In other cases, some form of treatment is required. The specific treatment depends on how long an individual has been in AF and the severity of symptoms.

The primary goals of AF treatment include the following:

  1. Restore a normal heart rhythm
  2. Slow the heart rate while a patient remains in AF
  3. Prevent blood clot formation and decrease the risk for stroke
  4. Decrease the risk for heart failure.


Other Treatments


AF is often a consequence of underlying heart problems; therefore, measures that prevent heart disease also reduce the risk of AF. Lifestyle factors like a healthy diet, regular exercise, quitting smoking, and avoiding alcohol abuse are recommended.


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Tina Shahian, PhD

Tina is a writer for Innerbody Research, where she has written a large body of informative guides about health conditions.


A communication specialist in life science and biotech subjects, Tina’s successful career is rooted in her ability to convey complex scientific topics to diverse audiences. Tina earned her PhD in Biochemistry from the University of California, San Francisco and her BS degree in Cell Biology from U.C. Davis. Tina Shahian’s Linkedin profile.


In her spare time, Tina enjoys drawing science-related cartoons.