1. From the Departments of Internal Medicine (Section on Cardiovascular Medicine) (J.H.J., S.V., M.E.H., D.W.K., V.T., W.G.H.), Public Health Sciences (R.B.D., T.L.L.), Biomedical Engineering (C.A.H.), Internal Medicine (Hematology and Oncology Section) (J.A.L., L.R.E.), and Radiology (W.G.H.), Wake Forest University School of Medicine, Winston-Salem, NC.