1. Cardiovascular Research Center, Massachusetts General Hospital, Boston, MA
2. Cardiac Arrhythmia Service, Massachusetts General Hospital, Boston, MA
3. Department of Biostatistics, Boston University School of Public Health, Boston, MA
4. Department of Cardiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
5. Section of Cardiovascular Medicine, Boston University School of Medicine, Boston, MA
6. Boston University's and National Heart, Lung and Blood Institute's Framingham Heart Study, Framingham, MA
7. Department of Medicine, Boston University School of Medicine, Boston, MA
8. Department of Cardiovascular Medicine, Cleveland Clinic, Cleveland, OH
9. Department of Medicine, University of Massachusetts Medical School, Worcester, MA
10. Department of Quantitative Health Sciences, University of Massachusetts Medical School, Worcester, MA
11. Department of General and Interventional Cardiology, University Medical Center Hamburg Eppendorf, Hamburg, Germany
12. Center for Population Studies, National Heart, Lung, and Blood Institute, Bethesda, MD
13. Department of Mathematics and Statistics, Boston University, Boston, MA
14. Department of Epidemiology, Boston University School of Public Health, Boston, MA
15. Preventive Medicine Section, Boston University School of Medicine, Boston, MA