In a randomized, controlled clinical trial, point-of care testing at the bedside using the cardiac biomarker troponin I in ED patients with possible ACS will be compared to traditional testing of this assay for myocardial necrosis obtained in the central laboratory. Our hypothesis: point-of-care testing for troponin I will decrease the time for disposition of patients with possible ACS in the emergency setting and decrease the time required for administering appropriate therapies for these patients.