Methods: This study will involve approximately 20 sites around the country. The study will be divided into two phases: a consecutive control data collection phase (Phase I) and an intervention with concurrent control phase (Phase II). Phase II will begin after installation of Welch Allyn ECG transmission equipment. The primary end-point will be time to reperfusion and secondary end-points will include myocardial salvage, aborted infarction and hospital mortality. ECG measurements will be made at a central ECG core lab by a blinded investigator.