1. From the Atrial Fibrillation Program, University of Utah School of Medicine (R.S.O., T.J.B., E.G.K., N.A., N.S.B., E.N.F., J.J.E.B., S.N.R., E.V.R.D., N.M.S., M.D., J.W., C.J.M., R.S.M., N.F.M.), and Scientific Computing Institute (R.S.O., J.J.E.B., R.S.M.) and Utah Center for Advanced Imaging Research (E.G.K., E.V.R.D., C.J.M., D.P.), University of Utah, Salt Lake City.