1. From the University of Colorado Medical Center, Aurora, CO (M.J.R.); Medtronic, Inc, Mounds View, MN (K.D.S., T.A.W.); Oklahoma Foundation for Cardiovascular Research, Oklahoma City, OK (P.B.A.); University of Minnesota Medical School, Minneapolis, MN (D.G.B.); and Medical University of South Carolina, Charleston, SC (M.R.G.).