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Atrial Fibrillation Fact Sheet

  • In atrial fibrillation (AFib), the electrical signals that coordinate the muscle of the upper chamber (atria) of the heart become rapid and disorganized; resulting in an irregular heartbeat (arrhythmia), often greater than 300 beats per minute. In atrial flutter (AFL), a single electrical wave circulates very rapidly in the upper chambers.
  • AFib is the most common sustained heart rhythm disorder and increases the risk for heart disease and stroke, both leading causes of death in the United States. An estimated 3 million adults in the United States have been diagnosed with atrial fibrillation.1
  • The likelihood of developing these arrhythmias increases with age. AFib is the most common heart rhythm abnormality in people over the age of 65, with a median age of 75 years. Approximately 70% of AFib patients are between 65 and 85 years old.2
  • The prevalence of AFib and AFL in the United States is projected to increase from about 3.4 million to 8-12 million over the next 30 to 40 years.3,4
  • Hospitalizations with atrial fibrillation as the primary diagnosis exceed 460,000 each year, and atrial fibrillation contributes to 80,000 annual deaths.5
  • AFib and AFL usually are not life threatening if treated properly.
  • AFib may last a short time and end spontaneously (paroxysmal AFib) or it may continue indefinitely (persistent or permanent AFib).
  • Many patients with paroxysmal AFib eventually develop permanent AFib.
  • The signs and symptoms of AFib vary, and may include a sudden flutter of the heart, anxiety, shortness of breath, weakness and difficulty exercising, chest pain, sweating, dizziness or fainting.
  • AFib may have no known cause, or it may be related to coronary heart disease, thyroid disease, high blood pressure, structural defects of the heart and its valves, lung disease or other disorders.
  • AFib is diagnosed by electrocardiogram (ECG), or with devices that are worn by the patient to monitor the heart over time (Holter monitor and event recorders).
  • AFib may increase the risk of blood clots and stroke, and causes 15 to 20 percent of ischemic strokes, where blood flow to the brain is blocked by clots or plaque in a blood vessel.3 Medications can be prescribed to prevent the blood clots from forming.
  • AFib sometimes requires treatment with medications, controlled electric shocks to the heart, or procedures that destroy the heart tissue that gives rise to the irregular heart rhythm. Less often, a pacemaker or another device is implanted to monitor and control the heart’s rhythm.

Download a PDF of Atrial Fibrillation fact sheet and learn more about the disease.


1  Naccarelli GV, Varker H, Lin J, Schulman KL. Increasing prevalenceof atrial fibrillation and flutter in the United States. Am J Cardiol.2009;104:1534-1539.

2  Fuster V, Rydén LE, Cannom DS, Crijns HJ, CurtisAB, Ellenbogen KA, Halperin JL, Kay GN, Le Heuzey J-Y, Lowe JE, Olsson SB, Prystowsky EN, Tamargo JL, Wann LS. 2011 ACCF/AHA/HRS focused updates incorporated into the ACC/AHA/ESC 2006 guidelines for the management of patients with atrial fibrillation: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol. 2011;57:e101–98.

3  Lloyd-Jones D, Adams RJ, Brown TM, et al. Heart Disease and Stroke Statistics—2010 Update. A Report from the American Heart Association Statistics Committee and Stroke Statistics Subcommittee. Circulation. 2010;121:e1-e170.Accessed August 15, 2012.

Naccarelli GV, Johnston SS, Dalal M, Lin J, Patel PP.Rates and Implications for Hospitalization of Patients>65 Years ofAge With Atrial Fibrillation/Flutter.Am J Cardiol. 2012;109:543-549.

5  Kim MH, Johnston SS, Chu BC, Dalal MR, Schulman KL. Estimation of total incremental health care costs in patients with atrial fibrillation in the United States.Circ Cardiovasc Qual Outcomes 2011;4:313–320.25.