1. From the Divisions of Cardiovascular Medicine (N.P.L., P.S.T., P.R.R., G.A.H., H.v.d.L., P.T.T., J.P.C., S.A.H., H.A.V., M.B.F.) and Pathology (M.E.B.), Stanford (Calif) University School of Medicine; and Department of Anesthesiology, University of Virginia School of Medicine, Charlottesville (C.X., R.A.J.).