1. Department of Emergency Medicine, University of Maryland, Baltimore, Maryland
2. Department of Emergency Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
3. Division of Cardiology Department of Epidemiology (SRE), University of Pittsburgh, Pittsburgh, Pennsylvania, Department of Emergency Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
4. Division of General Internal Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
5. Department of Emergency Medicine, University of Maryland, Baltimore, Maryland,