Atrial fibrillation is highly prevalent, although the exact prevalence is unclear.  As a condition, atrial fibrillation comes and goes, and is sometimes symptomatic, sometimes not.  It is difficult to capture these statistics for atrial fibrillation in surveys and epidemiological studies.  There are estimates that in 2010 in the United States, for example, the prevalence of atrial fibrillation varied between 2.7 and 6.7 million, ie, 1% - 2% of the population.[1][2][3]

We can see from Figure 2 that all estimates show that atrial fibrillation will become increasingly common over the next 40 years.  This is largely because we have an aging population, but also because we will look for atrial fibrillation more carefully.  It is also because patients with underlying heart disease, which in previous times might have killed the patient, will not cause mortality, but instead patients will survive long enough and with some degree of underlying cardiovascular disease so that atrial fibrillation will develop. Camm J. Am J Med 2013; published on-line at http://education.amjmed.com/00000.