1. From the Division of Cardiology (H.E.L., A.V., L.L., Y.B., D.G.H.), Department of Medicine, Emory University School of Medicine, Atlanta, GA; Max-Planck-Institute for Heart and Lung Research (S.O.), Bad Nauheim, Germany; Divisions of Clinical Pharmacology and Cardiology (D.G.H.), Department of Internal Medicine, Vanderbilt University, Nashville, TN.