1. From the Department of Medicine, Division of Cardiology (R.T.G., A.A.-Z., J.M.M., A.L.V., A.C.L., J.A.C.L.), Department of Biomedical Engineering (A.C.L.), Department of Radiology (F.M.B., J.A.C.L.), Johns Hopkins University School of Medicine, Baltimore, MD; Department of Nuclear Medicine, Hannover Medical School, Hannover, Germany (F.M.B.).