This would be consistent both with the clinical use of β1-AR antagonists for preventing postoperative AF [8], and the observation that carvedilol (α1-, β1-, β2-AR-antagonist) was more effective at preventing this arrhythmia than β1-AR antagonists [15, 23], although extra-AR actions of carvedilol [11] might also contribute. This evidence concerns the gene ADRB1 and atrial fibrillation.