1. Cardiac Electrophysiology Section, Department of Cardiovascular Medicine, Cleveland Clinic, OH (E.A.).
2. Department of Cardiology, Homolka Hospital, Prague, Czech Republic (P.N., V.Y.R., J.P.).
3. Helmsley Electrophysiology Center, Division of Cardiology, Icahn School of Medicine at Mount Sinai, New York, NY (V.Y.R.).
4. Division of Cardiology, Department of Internal Medicine, Samsung Medical Center, Sungkyunkwan university, Seoul, Republic of Korea (K.-M.P.).
5. Harvard-Thorndike Electrophysiology Institute, Cardiovascular Division, Department of Medicine (J.S., E.L., P.J.Z., A.E.B., A.G.K.), Beth Israel Deaconess Medical Center, Harvard Medical School.
6. Richard A. and Susan F. Smith Center for Cardiovascular Outcomes Research, Division of Cardiovascular Medicine (C.S.), Beth Israel Deaconess Medical Center, Harvard Medical School.
7. Department of Pharmacology, College of Physicians and Surgeons of Columbia University, New York, NY (A.L.W.).