1. From the SUNY Upstate Medical University (M.K.), Syracuse, N.Y.; Center for Arrhythmia Research (M.K., D.C., M.Y., S.Z., S.M., J.J., O.B., J.K.), University of Michigan, Ann Arbor, Mich.; Departamento de Anatomía Humana (D.S.Q.), UEX, Badajoz, Spain; Hospital Quiron-Madrid (J.A.C.), Pozuelo De Alarcon, Spain; Universidad Europea de Madrid (J.A.C.), Madrid, Spain; and Hospital Universitario Central de Asturias (D.C.), Area del Corazón, Spain.