1. From the Department of Medicine, Division of Cardiology, UT Southwestern Medical Center, Dallas, Tex (H.S.); Department of Radiology (R.C.G.) and Department of Medicine, Division of Cardiology (B.D.H.), Case Western Reserve University and University Hospitals of Cleveland, Cleveland, Ohio; and the Department of Medicine, Division of Cardiology, Mayo Clinic, Rochester, Minn (F.V.B.).