Print this page
 Email this page

 Connect with UMMC on:
 Twitter
 Facebook
 YouTube
iPhone

 Share this page:

Bookmark and Share

Home > Medical Reference > Encyclopedia (English)

Toggle: English / Spanish

 

Ask the Expert

Dr. Shorofsky’s Bio Image

Get answers to your Arrhythmia questions.

Dr. Shorofsky’s Bio | Q&A Archive

Note: This is for informational purposes only. Doctors cannot provide a diagnosis or individual treatment advice via e-mail. Please consult your physician about your specific health care concerns.

Video details

[ Flash player icon ] Please install flash player to see this video.

Heart Center Virtual Tour

Click to take a virtual tour

Related Content


 

Atrial fibrillation/flutter - Overview

Alternative Names

Auricular fibrillation; A-fib

Definition of Atrial fibrillation/flutter:

Atrial fibrillation/flutter is a heart rhythm disorder (arrhythmia). It usually involves a rapid heart rate, in which the upper heart chambers (atria) are stimulated to contract in a very disorganized and abnormal manner.

Causes, incidence, and risk factors:

Arrhythmias are caused by a disruption of the normal electrical conduction system of the heart.

Normally, the four chambers of the heart (two atria and two ventricles) contract in a very specific, coordinated way. The electrial impulse that signals your heart to contract in a synchronized way begins in the sinoatrial node (SA node). This node is your heart's natural pacemaker.

The signal leaves the SA node and travels through the two upper chambers (atria). Then the signal passes through another node (the AV node), and finally, through the lower chambers (ventricles). This path enables the chambers to contract in a coordinated fashion.

In atrial fibrillation, the atria are stimulated to contract very quickly and differently from the normal pattern. The impulses are sent to the ventricles in an irregular pattern. Some impulses fail to be transmitted. This makes the ventricles beat abnormally, leading to an irregular (and usually fast) pulse.

In atrial flutter, the ventricles may beat very fast, but in a regular pattern.

If the atrial fibrillation/flutter is part of a condition called sick sinus syndrome, the sinus node may not work properly. The heart rate may alternate between slow and fast. As a result, there may not be enough blood to meet the needs of the body.

Atrial fibrillation can affect both men and women. It becomes more common with increasing age.

Causes of atrial fibrillation include:

  • Reviewed last on: 5/15/2008
  • Alan Berger, MD, Assistant Professor, Divisions of Cardiology and Epidemiology, University of Minnesota, Minneapolis, MN. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

References

Fuster V, Rydén LE, Cannom DS, Crijns HJ, Curtis AB, Ellenbogen KA, et al. American College of Cardiology/American Heart Association Task Force on Practice Guidelines; European Society of Cardiology Committee for Practice Guidelines; European Heart Rhythm Association; Heart Rhythm Society. ACC/AHA/ESC 2006 Guidelines for the Management of Patients with Atrial Fibrillation: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and the European Society of Cardiology Committee for Practice Guidelines. Circulation. 2006;114:e257-e354.

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997- A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.
adam.com