Atrial fibrillation (also called AF or A Fib) is the most common form of sustained arrhythmia (heart rhythm disorder). Atrial fibrillation is more common in older people, people with high blood pressure, and people with other kinds of heart disease. It can lead to serious health problems such as stroke, fatigue, and heart failure. The January 27, 2010, issue of JAMA includes an article about treatments for atrial fibrillation. This Patient Page is based on one previously published in the December 19, 2007, issue of JAMA.