Abstract
Atrial fibrillation (AF), a rhythm characterized by disorganized depolarization of the atria, is frequently encountered in the clinical setting. This dysrhythmia significantly impacts hemodynamics, exercise tolerance, and quality of life. Many factors contribute to this complex dysrhythmia, ultimately leading to electrical and mechanical remodeling. Rhythm control has been the initial treatment choice for AF. However, until recently, differences in outcomes associated with rhythm control versus rate control for AF were unknown. Data from recent clinical trials suggest that rate control is equivalent to rhythm control in terms of mortality. In the rhythm-control group compared to the rate-control group, there was a tendency for increased hospitalizations and medication reactions (although these differences were not significant). Anticoagulation remains an important component of therapy when treating AF, but continues be to inadequately prescribed. Further, INRs commonly are not maintained in a therapeutic range. Finally, the results of the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM), Pharmacological Intervention in Atrial Fibrillation (PIAF), and the Comparison of Rate Control and Rhythm Control in Patients with Recurrent Persistent Atrial Fibrillation (RACE) trials provide guidance in treatment strategies for AF.
Atrial fibrillation (AF) is a rapid and disorganized depolarization of the atria. It is a common rhythm disturbance in adults, and is frequently encountered in the clinical setting. The Framingham Study reported that the incidence of AF rises significantly with increasing age, from 0.2 per 1000 at ages 30-39, to 39 per 1000 at ages 80-89 years. 1 Atrial fibrillation is more prevalent among men than among women. 2,3 Age-adjusted risk of developing AF appears to be higher in whites compared to blacks. 4 It is frequently associated with heart disease and has been reported to occur in 15% to 30% of heart failure patients. 5,6 One of every 6 patients diagnosed with stroke has AF. 7 Studies indicate that individuals with AF may have twice the mortality rate compared to individuals in sinus rhythm. 8
Even though AF is the most common cardiac dysrhythmia and is associated with serious consequences, the optimal treatment strategy for AF remains unknown. Recent clinical trials have compared the treatment strategies of rate control versus rhythm control. The emphasis of this article is on the research findings from recent clinical AF trials. To set the stage for these results, the classification of AF, mechanism, and other AF treatment strategies are briefly reviewed.