1. Division of Cardiology, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas (M.S.S., I.E., S.G.)
2. Department of Internal Medicine, Mayo Clinic College of Medicine and Science, Rochester, Minnesota (C.L.C.)
3. Division of General Internal Medicine, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas (R.A.A.)
4. Department of Medicine, Cardiology, University of Nevada Reno School of Medicine, Reno, Nevada (L.E.B.T.).