A comprehensive insight of novel antioxidant therapies for atrial fibrillation management.

Atrial fibrillation (AF) is the most common arrhythmia in clinical practice and is associated with decreased quality of life, and increased mortality and morbidity from stroke and thromboembolism. The underlying mechanisms involved in the development of AF have yet to be fully elucidated. However, once initiated, AF tends to self-perpetuate, due to structural and electrical remodeling in the atria. Currently, therapies for AF, such as, antiarrhythmic drugs and catheter ablation, have significant limitations. Antiarrhythmic drugs target one or a few cardiomyocyte ion channels and have considerable pro-arrhythmic and non-cardiac adverse effects. On the other hand, catheter ablation is an expensive treatment associated with measurable complications and its long-term success in management of AF is controversial. Current consensus guidelines recommend β-blockers, amiodarone, digitalis glycosides and non-dihydropyridine calcium channel antagonists or a combination of them for AF treatment, but bradycardia and heart block may occur as an unwanted effect. On the other hand, antioxidant agents have recently attracted much interest in AF treatment because they have been associated with a reduction in lone AF and post-operative AF, and in some cases, with a decrease in long-term hospitalization time. Moreover, antioxidants can be considered a cheap treatment with reduced side effects. In this review, we will comprehensively review the effects and the mechanisms of action of several antioxidant agents, such as vitamin E, ascorbic acid, carotenoids, statins, omega-3 polyunsaturated fatty acids and N-acetylcysteine.