1. Cardiac Ultrasound Laboratory; Massachusetts General Hospital and Harvard Medical School; Boston Massachusetts
2. Department of Cardiovascular Medicine; Division of Cardiology; National Heart and Lung Institute and Imperial College; London United Kingdom
3. Department of Medicine; Montreal Heart Institute; Montreal Canada
4. Department of Cardiology; La Paz University Hospital; Madrid Spain
5. Center of Cardiology and Angiology; Vilnius University Hospital Santariskiu Clinic; Vilnius Lithuania
6. Division of Cardiology; V.A. North Texas Health Care System; Dallas Texas
7. Division of Cardiology; Saint Michael's Hospital; Toronto Canada
8. Department of Medicine; Specialty Hospital; La Raza National Medical Center; Mexico City Mexico
9. Department of Internal Medicine; University Clinic of Cardiology; Skopje Macedonia
10. Department of Medicine; Division of Cardiology; University of Ottawa Heart Institute; Ottawa Canada
11. Department of Medicine; Division of Cardiology; Monza Polyclinic; Monza Italy
12. Department of Medicine; Division of Cardiology; Englewood Hospital and Medical Center; Englewood New Jersey
13. Department of Medicine; Division of Cardiology; New York University Medical Center; New York New York
14. Department of Medicine; Division of Cardiology; Loyola University Medical Center; Maywood Illinois
15. Department of Medicine; New York Medical Associates; New York New York
16. Department of Medicine; Division of Cardiology; Emory University School of Medicine; Atlanta Georgia
17. Department of Medicine; Division of Cardiology; New York University Langone Medical Center; New York New York