1. From the Wallace H. Coulter Department of Biomedical Engineering at Emory University and Georgia Institute of Technology (K.D.P., S.T.V., K.M.-R., M.E.B., W.R.T., M.E.D.), Atlanta, Ga; the Division of Cardiology (K.D.P., S.T.V., K.M.-R., M.E.B., W.R.T., M.E.D.), Emory University School of Medicine, Atlanta, Ga; Petit Institute for Bioengineering and Bioscience (W.R.T., M.E.D.), Atlanta, Ga; and the Division of Cardiology (W.R.T.), Atlanta VA Medical Center, Decatur, Ga.