1. From the Division of Cardiology (A.L.B., R.B.W., M.H.P., A.M.H.), Massachusetts General Hospital, and Department of Medicine (A.L.B., R.B.W., M.H.P., A.M.H.), Harvard Medical School, Boston, Mass; Biological Psychiatry Laboratory (G.K., J.I.H., H.G.P.), McLean Hospital, Belmont, Mass; and Department of Psychiatry (G.K., J.I.H., H.G.P.), Harvard Medical School, Boston, Mass.