free guide

What is AF?

Atrial fibrillation refers to the atria, which are the two upper chambers of the heart. In AF, muscle fibres of the atria fibrillate meaning they twitch or beat in an uncoordinated way.

Understanding atrial fibrillation

Atrial fibrillation (AF) affects almost nine million people in Europe and the United States,1,2 and is the most common heart rhythm abnormality for adults.3 This website is designed to give you a better understanding of AF and the importance of following your doctor’s advice.

AF is a condition which causes the heart to beat either too quickly or too slowly.4 As you probably know the heart’s job is to pump blood around the body. It does so with a regular squeezing action which we call our heartbeat, and normally our heart beats in a steady rhythm.

AF interferes with this usual rhythm, which means blood cannot be pumped around the body as efficiently. Unfortunately this leads to an increase in the risk of having a stroke and is why following your doctor’s advice is crucial.


1. Fuster V, Rydn LE, Cannom DS, et al. ACC/AHA/ESC 2006 Guidelines for the management of patients with atrial fibrillation. Circulation 2006; 114:e257-e354.
2. Miyasaka Y, et al. Secular trends in incidence of atrial fibrillation in Olmsted County, Minnesota 1980 to 2000, and implications on the projections for future prevalence. Circulation 2006; 114:119-125.
3. Stewart S, Murphy N, Walker A, et al. Cost of an emerging epidemic: an economic analysis of atrial fibrillation in the UK. Heart 2004; 90:286-92. 
4. Information about NICE clinical guideline 36. National Institute for Health and Clinical Excellence. June 2006.