1. From the Department of Cardiology, Beth Israel Deaconess Medical Center (M.R.R.) and the VA Boston Healthcare System (M.R.R.), Boston, MA; S2 Statistical Solutions Inc., Cincinnati, OH (C.L.G., T.D.H.); Department of Medicine, New York University School of Medicine, New York, NY (J.A.L.); Biosense Webster, Inc., Diamond Bar, CA (J.L.M., M.Z.); and Sutter Pacific Medical Foundation, San Francisco, CA (S.C.H.).