A systematic review included 45 studies with a total of 2 059 subjects. The authors conclude that the calcium-channel blockers verapamil and diltiazem, or select beta-blockers, are efficacious for heart rate control at rest and during exercise for patients with atrial fibrillation, without a clinically-important decrease in exercise tolerance. Selected beta-blockers, such as the non-cardioselective beta-antagonist nadolol or the second-generation beta-1-antagonists atenolol and metoprolol, are efficacious at rest and with exercise. There is some evidence, however, that beta-blockers cause a transient decrease in exercise tolerance. Digoxin is useful when rate control during exercise is less of a concern.