1. Department of Cardiology, GKT School of Medicine; King's College; Bessemer Road, Denmark Hill London SE5 9PJ UK
2. The North Staffordshire Cardiac Centre; Princes Road UK
3. Medical Statistics Unit University of Edinburgh; UK
4. Pontefract and Wakefield Hospitals; UK
5. Freeman Hospital Newcastle; UK
6. Medical College of Virginia; Virginia Commonwealth University; Virginia USA
7. Bradford Royal Infirmary, Dunkworth Lane; Bradford Yorkshire BD9 6RJ UK
8. Lincoln County Hospital; Greetwell Road Lincoln Licolnshire LN2 5QY UK
9. Department of Cardiology; University of Edinburgh; UK