1. Denver Health Medical Center, University of Colorado School of Medicine, Denver Colorado, USA
2. Emergency Department, Kettering General Hospital, Kettering, UK
3. Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
4. Department of Emergency Medicine, Alexandria University, Alexandria, Egypt
5. Emergency Department, Ramón y Cajal University Hospital, Madrid, Spain
6. Health Science Department, Section of Anesthesia and Critical Care, University of Florence, Florence, Italy
7. Department of Anesthesia and Critical Care, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy