Atrial fibrillation/flutter

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 that is not regular.

Causes, incidence, and risk factors

are caused by problems with the heart’s normal electrical conduction system.


You may not be aware that your heart is not beating in a normal pattern, especially if it has been occurring for some time.

Signs and tests

The health care provider may hear a fast heartbeat while listening to the heart with a stethoscope. The pulse may feel rapid, irregular, or both. The normal heart rate is 60 – 100, but in atrial fibrillation/flutter the heart rate may be 100 – 175. may be normal or low.


In certain cases, atrial fibrillation may need emergency treatment to get the heart back into normal rhythm. This treatment may involve electrical or intravenous (IV) drugs such as dofetilide, amiodarone, or ibutilide. Drugs are typically needed to keep the pulse from being too fast.

Expectations (prognosis)

The disorder is usually controllable with treatment. Many people with atrial fibrillation do very well.


Issam Mikati, MD, Associate Professor of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc. – 5/9/2010

Heart, section through the middle
Heart, front view
Posterior heart arteries
Anterior heart arteries

ADAM Medical Encyclopedia

Article written by

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission ( URAC's accreditation program is an independent audit to verify that A.D.A.M. follows rigorous standards of quality and accountability.