1. Department of Medicine, Division of CardiologyUniversity of Mississippi Medical Center Jackson Mississippi
2. Department of MedicineIndiana University Indianapolis Indiana
3. Medtronic Mounds View Minnesota
4. Medtronic Maastricht The Netherlands
5. Section of Cardiac Electrophysiology, Perelman School of Medicine at the University of Pennsylvania Philadelphia Pennsylvania
6. Department of EpidemiologyJohns Hopkins Bloomberg School of Public Health Baltimore Maryland
7. Division of CardiologyJohns Hopkins University School of Medicine Baltimore Maryland