New Antiarrhythmic Agents for the Prevention and Treatment of Atrial Fibrillation

Rhythm control could become the preferred treatment strategy for atrial fibrillation (AF) if the available antiarrhythmic agents were more effective and safe. A subanalysis of the AFFIRM trial data suggested that rhythm control, if achieved without the adverse effects related to antiarrhythmic medications, may offer a significant survival advantage over rate control. This article reviews the new investigational pharmacologic and dietary agents being considered for the prevention and treatment of AF. Dronederone is a benzofurane similar to amiodarone, but without the iodine component, and is devoid of many of the amiodarone systemic toxicities. Azimilide is a delayed rectifier potassium channel blocker with use-dependent effects. Agents that target the ultra rapid component of the delayed rectifier potassium current (I_Kur) have atrial myocyte specific properties and may be devoid of QT prolongation and torsade de pointes in clinical usage. Newer agents being studied also include fish oil, gap junction modulators, 5HT4 receptor antagonists, angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers, and HMG CoA reductase inhibitors. There is considerable hope that at least some of these agents will ultimately be available for more effective and safe clinical treatment and prevention of AF.