1. From the Departments of Cardiology and
2. Department of Pediatrics, Harvard Medical School;
3. Medicine, Children's Hospital;
4. Department of Pediatrics, Boston Medical Center and Boston University School of Medicine;
5. Division of General Medicine, Brigham and Women's Hopsital;
6. Department of Epidemiology, Harvard School of Public Health; and
7. Department of Epidemiology and Biostatistics, Boston University School of Public Health.