Pulmonary Vein Myocardium as a Possible Pharmacological Target for the Treatment of Atrial Fibrillation

The pulmonary vein has a unique electrophysiological property showing an autonomic electrical activity, and this phenomenon has been further focused on as a source of triggers of atrial fibrillation. The pulmonary vein cardiomyocytes have shorter action potential duration, less negative resting membrane potential, and smaller maximum upstroke velocity than those in the left atrium, whose underlying cellular mechanisms may generate arrhythmogenic substrates such as abnormal automaticity and triggered activity. In diseased conditions including sustained atrial tachycardia or chronic volume overload, its arrhythmogenic profile can be further modified through abbreviation of action potential duration of the pulmonary vein myocardium, which may become a cause of reentry. Recently, antiarrhythmic effects of various drugs have been extensively investigated in isolated pulmonary vein preparations. The present review article highlights the recent advances in our understanding of electrophysiological and pharmacological profiles of the pulmonary vein.