1. Department of Medicine, Division of Cardiology, Cardiovascular Research Center, Corrigan Minehan Heart Center, Massachusetts General Hospital, Harvard Medical School, Boston (M.H.H., J.S.G., B.A., N.E.H., A.A.K., H.L., C.S., A.P.S., J.D.R., A.R.).
2. Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor (J.J.H.).
3. Cardiovascular Medicine, Perelman School of Medicine‚ University of Pennsylvania, Philadelphia (S.M.D.).