Although thrombolysis is being performed at community hospitals or enroute to hospitals by specially trained teams using helicopter transport, only one major study has been reported which has systematically evaluated the benefit of early on-the-scene thrombolysis. This study documented significant benefit in terms of salvage of myocardium over those patients in whom thrombolytic therapy was initiated after arrival in the hospital, as a direct function of time. This program used physicians in the ambulance to evaluate indications for and contraindications to thrombolytic therapy in the field. The proposed study would evaluate the ability of paramedics, under physician remote control, to accurately evaluate patients in the field in terms of indications and contra-indications to thrombolytic therapy, and to assess the possible benefit in terms of salvage of myocardium in those patients being transported to the hospital by paramedic squads as opposed to those arriving by ordinary means.