1. From the Cardiovascular Division, Clinical Cardiac Electrophysiology, Department of Internal Medicine (R.P.), The University of Texas Southwestern Medical Center, Dallas; the Division of Cardiology, Department of Medicine (R.P.), University of Washington School of Medicine, Seattle; Procter & Gamble Pharmaceuticals (T.T., D.S., S.M.), Cincinnati, Ohio; the Department of Medicine (S.C.), McMaster University, Hamilton, Ontario, Canada; and the Department of Biostatistics and Bioinformatics (W.W.)...