Effect of ambulance 12-lead ECG recording on times to hospital reperfusion in acute myocardial infarction

Objective: To review the evidence that recording a prehospital 12-lead electrocardiogram (ECG) reduces time from hospital arrival to initiation of reperfusion therapy for acute myocardial infarction (AMI). Data sources: Medline search from 1966 to the present (articles in all languages) and examination of bibliographies. Study selection: Published studies of prehospital 12-lead ECG recording that included control groups and reported time intervals from hospital arrival to start of reperfusion therapy. Data extraction: Eight articles satisfied selection criteria (two randomised controlled trials, four non-randomised interventional studies and two prospective observational studies). Data synthesis: Widely varying study methodologies precluded meta-analysis. All studies had methodological problems, but hospital delays were consistently reduced. Such improvements appear to be small in hospitals where delays are already minimal. Conclusions: Little evidence is available to support routine prehospital 12-lead ECG recording if the median hospital time to reperfusion is already less than 30 minutes. Improvement of in-hospital treatment times may be a better initial strategy than prehospital 12-lead ECG recording, as this will benefit more patients and allow ambulance services to better allocate their available resources.