1. From the Department of Medicine (D.D.C., D.L.L.) and Department of Pathology and Laboratory Medicine (N.J.H., K.B.N.), University of Vermont, College of Medicine, Burlington, VT; Fletcher Allen Health Care, Burlington, VT (D.D.C., N.J.H., K.B.N., D.L.L.); Department of Cardiology, Hartford Hospital, Hartford, CT (E.M.C.); and Cardiovascular Research Institute, Burlington, VT (D.L.L.).