1. From the Department of Internal Medicine, Division of Cardiology, University of Michigan, Ann Arbor (H.G., K.B., M.Y., F.M., F.B.); Department of Internal Medicine, Cardiovascular Division, Brigham and Women Hospital, Boston, MA (W.S.); Arrhythmia Unit and Electrophysiology Laboratories, San Raffaele Hospital, Milano, Italy (P.D.B., P.V.); Klinik für Kardiologie II, Herz- und Gefäß-Klinik GmbH, Bad Neustadt, Germany (T.D.); Hanseatisches Herzzentrum, Asklepios Klinik St. Georg, Hamburg, Germany (K....