1. From the Division of Cardiology, Department of Medicine, Emory University School of Medicine, Atlanta, GA (A.N.L., G.J., A.E.F., D.W., N.L., W.R.T.); The Wallace H. Coulter Department of Biomedical Engineering, Emory University School of Medicine and Georgia Institute of Technology, Atlanta, GA (W.R.T.); and Division of Cardiology, Atlanta Veterans Affairs Medical Center, Atlanta, GA (W.R.T.).