Vagal Atrial Fibrillation

Abstract

The autonomic nerve system plays an important role in atrial fibrillation (AF). Vagal AF refers AF (generally paroxysmal) arising in contexts of enhanced parasympathetic tone. Heterogeneity of refractoriness and action potential abbreviation resulting from spatially variable parasympathetic enhancement of the acetylcholine-dependent K(superscript +)-current (I(subscript KACh)) underlie vagal AF. Adrenergic influences may also contribute to the occurrence of vagal AF. Cholinergic stimulation may enhance ectopic firing from pulmonary vein cardiomyocytes, which potentially contribute to the occurrence of vagal AF. On the other hand, underlying heart disease modulates cholinergic regulation of atrial myocytes. Careful history taking in AF patients is important for vagal AF management. Vagal denervation may play a role in the efficacy of ablation procedures, but the results are conflicting. Specific I(subscript KACh) channel blockers may become the treatment of choice in the future.