Maintenance of sinus rhythm as a therapy goal

Despite recent advances in our understanding of the mechanisms and consequences of atrial fibrillation, appropriate management of this common condition presents something of a dilemma. Control of ventricular rate alone is a common strategy, considered by many physicians to be the safest treatment option and a relatively simple approach to preserving left ventricular function. Rhythm control using antiarrhythmic agents, however, offers a number of important advantages, with the potential to correct abnormal physiology, increase exercise tolerance, reduce thromboembolic risk, prevent atrial remodelling and eliminate the risk of tachycardia-induced cardiomyopathy. Selection of an appropriate antiarrhythmic agent for such long-term prophylaxis is however problematic. Class I agents are associated with an unacceptable proarrhythmic risk especially in patients with structural heart disease and long-term therapy with the class III agent amiodarone can result in serious non-cardiac adverse effects. It is apparent, therefore, that there is little consensus on appropriate management strategies for atrial fibrillation and less still on the antiarrhythmic agent to be used. A number of studies are, however, ongoing which attempt to determine the benefits of rhythm versus rate control. These include the PIAF (Pharmacological Intervention in Atrial Fibrillation), AFFIRM (Atrial Fibrillation Follow-up Investigation of Rhythm Management) and RACE (Rate Control versus Electrical Cardioversion) studies, which should provide valuable answers which will help to guide physicians in their therapy choices.