1. Department of Cardiovascular Medicine and Heart and Vascular Institute, Cleveland Clinic, OH (B.L.W., K.G.T.).
2. Clinical and Public Health Medicine, University of Modena and Reggio Emilia, Modena, Italy (G.B.).
3. Department of Cardiology, Section of Electrophysiology, Valley Health System, Ridgewood, NJ (S.M.).
4. Department of Medicine, University of Washington School of Medicine, Seattle (J.E.P.).
5. The Sahlgrenska Academy, University of Göteborg, Sweden (C.K.).
6. Department of Medicine, Duke Clinical Research Institute, Durham, NC (G.R.C.).
7. Maine Medical Partners, Maine Medical Center, Portland (J.C.L.).
8. Department of Internal Medicine, Ohio State University, Columbus (R.A.).
9. Department of Heart Disease, University of Bergen and Haukeland University Hospital, Norway (S.F.).
10. ARK-LA-TEX Cardiology, Christus Highland Hospital, Shreveport, LA (S.S.W.).
11. Population Health Research Institute, McMaster University, ON, Canada (J.S.H.).
12. Cardiac Rhythm & Heart Failure (CRHF) Therapy Development and Clinical Research, Medtronic, Mounds View, MN (R.H., J.D.L., D.R.L., S.W.).