Effect of time to electrocardiogram on time from electrocardiogram to fibrinolysis in acute myocardial infarction patients

CJEM. 2011 Mar;13(2):79-89. doi: 10.2310/8000.2011.110261.


Objective: The American Heart Association (AHA) recommends a benchmark door-to-electrocardiogram (ECG) time of 10 minutes for acute myocardial infarction patients, but this is based on expert opinion (level of evidence C). We sought to establish an evidence-based benchmark door-to-ECG time.

Methods: This retrospective cohort study used a population-based sample of patients who suffered an ST elevation myocardial infarction (STEMI) in Ontario between 1999 and 2001. Using cubic smoothing splines, we described (1) the relationship between door-to-ECG time and ECG-to-needle time and (2) the proportion of STEMI patients who met the benchmark door-to-needle time of 30 minutes based on their door-to-ECG time. We hypothesized nonlinear relationships and sought to identify an inflection point in the latter curve that would define the most efficient (benefit the greatest number of patients) door-to-ECG time.

Results: In 2,961 STEMI patients, the median door-to-ECG and ECG-to-needle times were 8.0 and 27.0 minutes, respectively. There was a linear increase in ECG-to-needle time as the door-to-ECG time increased, up to approximately 30 minutes, after which the ECG-to-needle time remained constant at 53 minutes. The inflection point in the probability of achieving the benchmark door-to-needle time occurred at 4 minutes, after which it decreased linearly, with every minute of door-to-ECG time decreasing the average probability of achievement by 2.2%.

Conclusions: Hospitals that are not meeting benchmark reperfusion times may improve performance by decreasing door-to-ECG times, even if they are meeting the current AHA benchmark door-to-ECG time. The highest probability of meeting the reperfusion target time for fibrinolytic administration is associated with a door-to-ECG time of 4 minutes or less.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Benchmarking
  • Electrocardiography
  • Female
  • Humans
  • Male
  • Middle Aged
  • Myocardial Infarction / diagnosis
  • Myocardial Infarction / drug therapy*
  • Myocardial Reperfusion / standards*
  • Ontario
  • Outcome Assessment, Health Care*
  • Retrospective Studies
  • Thrombolytic Therapy*
  • Time Factors
  • Triage