1. Department of Cardiology, Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA (E.K.Z., S.C., M.A.H., M.M.K.).
2. Sarver Heart Center, University of Arizona, Tucson (A.M.W.).
3. Department of Cardiology, Medical University of South Carolina and Ralph H. Johnson Veterans Administration Medical Center, Charleston (M.R.Z.).
4. Cardiovascular Division, Brigham and Women’s Hospital, Boston, MA (S.D.S.).