Atrial fibrillation (Afib or AF) is an irregular heart rhythm that originates in the upper chambers of the heart called the atria. Normally the heart’s pacemaker called the sinoatrial (SA) node controls the heart’s rhythm by generating electrical impulses that are transmitted throughout the heart in a very organized manner, causing the heart muscle to contract in a coordinated fashion.
When a patient has Afib, rather than an electrical impulse from the SA node initiating and controlling the heart’s contraction, the electrical impulses are initiated in other areas causing cardiac contraction to become disorganized. As a result, the atria fibrillate in an uncoordinated manner.
Afib is the most common heart rhythm disorder, and its incidence increases with age1,2. Approximately 1% of patients younger than 60 years and about 8% of patients older than 80 years are affected3. Simply put, Afib is a malfunction of the heart’s electrical system, which causes an irregular heartbeat.
When Afib occasionally comes and goes it is referred to as paroxysmal atrial fibrillation, whereas chronic Afib is often referred to as permanent or persistent atrial fibrillation. Afib can also be classified based on whether it is caused by valvular disease or a prosthetic heart valve (valvular vs. non-valvular AF).
While non-valvular AF increases the risk of stroke by up to 5-times, valvular atrial fibrillation carries the highest risk of stroke (a 17-times increase as compared to the general population)4. To further compound the problem, this stroke risk is independent of whether or not the patient experiences symptoms. However, with proper treatment, people who have Afib can live normal, active lives.
- Rosamond W, et al. Heart disease and stroke statistics—2008 update: a report from the American Heart Association Statistics Committee and Stroke Statistics Subcommittee [published correction appears in Circulation. 2010;122(1):e10].
- Lloyd-Jones DM, Wang TJ, Leip EP, et al. Lifetime risk for development of atrial fibrillation: the Framingham Heart Study. Circulation. 2004;110(9):1042–1046.
- Singer DE, Albers GW, Dalen JE, Go AS, Halperin JL, Manning WJ. Antithrombotic therapy in atrial fibrillation: the Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy. Chest. 2004;126(3 suppl):429S–456S.
- Fuster V, Ryden LE, Cannom DS et al. 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. Circulation 2011;123:e269–e367.