In February, the Los Angeles City and County Fire Department Emergency Medical Services began using a new system for assessing people with symptoms of heart attacks. The 12-lead electrocardiogram (EKG) system, previously only available in hospitals, replaced the departments' previous 4-lead system and will allow paramedics to determine in two minutes whether a patient is experiencing an acute heart attack. With a $3 million grant from the Radnor, Pa.-based Annenberg Foundation, the departments purchased more than 170 units and will work with the Dallas-based American Heart Association to provide advanced cardiac life support training for 1,450 paramedics, data tracking and program analysis.