Atrial Fibrillation (AFib)

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Atrial fibrillation (AFib) facts

  • Atrial fibrillation is also referred to as AF, AFib, atrial fib, and A-Fib.
  • Atrial fibrillation (AFib) is an abnormal rhythm of the heart.
  • Atrial fibrillation is caused by abnormal electrical discharges within the atria.
  • Atrial fibrillation reduces the ability of the atria to pump blood into the ventricles and usually causes the heart to beat too rapidly.
  • Symptoms of atrial fibrillation include:
  • Complications of atrial fibrillation include heart failure and stroke.
  • Atrial fibrillation can be diagnosed by physical examination, electrocardiogram, Holter monitor, or patient-activated event recorder.
  • Treatment of AFib is directed toward controlling underlying causes, slowing the heart rate and/or converting the heart to normal rhythm, and stroke prevention using blood-thinning medications.
  • Medications are commonly used in the longer term to control or prevent recurrence of AFib, but medications may not be effective and may have intolerable side effects.
  • Electrical cardioversion is successful in over 95% of patients with AFib, but 75% of patients have a recurrence of AFib within 1 to 2 years.
  • Some doctors may leave patients in AFib for the longer term provided the heart rate is under control, blood flow is adequate, and blood is adequately thinned with medications.
  • Non-medication treatments of atrial fibrillation include pacemakers, AV node ablation, atrial defibrillators, and the Maze procedure.
  • Pulmonary vein isolation shows promise for the treatment of atrial fibrillation and has a high rate of success; however, longer-term experience is necessary.

What is atrial fibrillation (AFib)?

Atrial fibrillation (AFib) is the most common, abnormal rhythm of the heart.

The heart contracts (beats) and pumps blood with a regular rhythm, for example, at a rate of 60 beats per minute there is a beat every second. The heart may beat faster or slower with a shorter or longer interval between beats, but at any one rate the interval between beats is constant. This regular rhythm occurs as a result of regular electrical discharges (currents) that travel through the heart and cause the muscle of the heart to contract. In AFib, the electrical discharges are irregular and rapid and, as a result, the heart beats irregularly and, usually, rapidly.

Atrial fibrillation is common; half a million new cases are diagnosed yearly in the U.S., and billions of dollars are spent annually on its diagnosis and treatment.

Medically Reviewed by a Doctor on 5/4/2015

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Atrial Fibrillation Symptoms and Signs

Symptoms of atrial fibrillation occur when the upper chambers of the heart (atria) beat in a disorganized fashion. Atrial fibrillation is a type of arrhythmia. Characteristic symptoms include:

  • shortness of breath,
  • palpitations, and
  • lightheadedness.

Other symptoms of atrial fibrillation are:

  • fatigue,
  • confusion, and
  • a reduced tolerance for exercise.