1. Division of Cardiology; UCLA Medical Center; Los Angeles California
2. Clinical Department; Cardiovascular Systems Inc.; St. Paul Minnesota
3. The Cardiac and Vascular Institute; Gainesville Florida
4. Department of Cardiology; St. Francis Hospital-The Heart Center; Roslyn New York
5. Utah Cardiology; Layton Utah
6. Metropolitan Heart and Vascular Institute, Mercy Hospital; Minneapolis Minnesota