1. From The Lindner Center and Ohio Heart Health Center, Cincinnati, Ohio (E.S.C.); the Division of Circulatory Physiology, Columbia University College of Physicians and Surgeons, New York, NY (M.P.); Cardiac, Vascular, and Pulmonary Clinical Research and Development, Centocor, Malvern, Pa (K.H.L., A.A.F.); the Department of Medicine, University of Texas Health Science Center and Texas Heart Institute, Houston (J.T.W.); and the Collaborative Organization for Research Endeavors (CORE) (J.T.W., M.P.).