The natural history of AFib usually begins with the risk factors that are associated with the arrhythmia, such as hypertension, coronary artery disease, heart failure, sleep apnea, and obesity.[53] These lead to changes within the atria, both in the muscular function of the heart, as well as in the electrical stability of the heart, and when this develops into AFib, the presentation tends to be paroxysmal.  Over time, as these changes progress, the arrhythmia becomes more persistent, and eventually the patient enters permanent AFib.

Rothman SA. Am J Med 2013; 126: 00-00.