The failure of years of experience with electrocardiographic transmission from paramedics to the hospital emergency department to reduce the delay from door to primary coronary intervention below the 90-minute threshold during acute myocardial infarction.

INTRODUCTION: Emergency medical services (EMS), hospital emergency departments, and cardiologists have taken steps to reduce time to reperfusion therapy by implementation of aggressive acute myocardial infarction treatment and triage protocols. Data indicate that significant myocardial salvage requires reperfusion within 2 hours, and the current American College of Cardiology guideline is 90 minutes after hospital emergency department admission.

MATERIALS AND METHODS: To minimize delays in time to reperfusion in an urban-rural North Carolina County, Guilford County EMS and the Moses Cone Hospital have collaborated to implement transmission of EMS electrocardiographs (ECGs) to the emergency department. The study population included 92 patients who were transported by EMS and received primary coronary intervention during the second, third, and fourth years after initiation of this intervention in 1993.

RESULTS: The median time from symptom onset to the initial ECG was 77 minutes. There was an additional 23 minutes between the availability of this ECG and the arrival of the patient at the emergency department. In the first year of the intervention, the time from hospital arrival to percutaneous coronary intervention was 80 minutes. In years 2 through 4, they were 93, 85, and 94 minutes, respectively. In 2003, 10 years after the intervention, the time from hospital arrival to percutaneous coronary intervention was 113 minutes.

CONCLUSION: Initial gains in the time from hospital arrival to percutaneous coronary intervention, attributed to acquisition of the ECG in the prehospital setting, were not sustained over 10 years.