Based on the patient's symptoms suggestive of MI, my first action would be to assess ABC (airway, breathing, and circulation) to ensure the patient's airway is open, breathing is adequate, and circulation is stable. Then, I would obtain an EKG to confirm the diagnosis of MI. If the EKG shows evidence of MI, I would administer aspirin and provide prehospital notification to the receiving hospital. If considering prehospital fibrinolysis, I would use the fibrinolytic checklist. I would also consider oxygen, nitroglycerin, and morphine if needed.