Development and Validation of a Prioritization Rule for Obtaining an Immediate 12-lead Electrocardiogram in the Emergency Department to Identify ST-elevation Myocardial Infarction

Seth W. Glickman, MD, MBA; rances S. Shofer, PhD; Michael C. Wu, PhD; Matthew J. Scholer, MD, PhD; Adanma Ndubuizu, MD, MPH; Eric D. Peterson, MD, MPH; Christopher B. Granger, MD; Charles B. Cairns, MD; Lawrence T. Glickman, VMD, DrPH; Chapel Hill; Durham, NC


Am Heart J. 2012;163(3):372-382. 

In This Article

Abstract and Introduction


Background: Current guidelines recommend an immediate (eg, <10 minutes) 12-lead electrocardiogram (ECG) to identify ST-elevation myocardial infarction (STEMI) among patients presenting to the emergency department (ED) with chest pain. Yet, one third of all patients with myocardial infarction do not have chest pain. Our objective was to develop a practical approach to identify patients, especially those without chest pain, who require an immediate ECG in the ED to identify STEMI.
Methods: An ECG prioritization rule was derived and validated using classification and regression tree analysis among >3 million ED visits to 107 EDs from 2007 to 2008.
Results: The final study population included 3,575,178 ED patient visits; of these, 6,464 (0.18%) were diagnosed with STEMI. Overall, 1,413 (21.9%) of patients with STEMI did not present to the ED with chest pain. Major predictors of those requiring an immediate ECG in the ED included age ≥30 years with chest pain; age ≥50 years with shortness of breath, altered mental status, upper extremity pain, syncope, or generalized weakness; and those with age ≥80 years with abdominal pain or nausea/vomiting. When the ECG prioritization rule was applied to a validation sample, it had a sensitivity of 91.9% (95% CI 90.9%-92.8%) for STEMI and a negative predictive value 99.98% (95% CI 99.98%-99.98%).
Conclusion: A simple ECG prioritization rule based on age and presenting symptoms in the ED can identify patients during triage who are at high risk for STEMI and therefore should receive an immediate 12-lead ECG, often before they are seen by a physician.


Coronary heart disease including ST-elevation myocardial infarction (STEMI) is the leading cause of death worldwide, although outcomes for patients with STEMI can be significantly improved by timely reperfusion therapy.[1–3] A critical component of STEMI care is prompt diagnosis with a 12-lead electrocardiogram (ECG) in either the emergency department (ED) or prehospital setting. The American College of Cardiology/American Heart Association guidelines state that an "ECG should be performed within 10 minutes of ED arrival for all patients with chest discomfort or other symptoms suggestive of STEMI.[4]

One challenge for early diagnosis of STEMI is that one third of patients with myocardial infarction (MI) will not have chest pain.[5–9] Current guidelines do not include a standardized approach to determine which patients without chest pain should receive an immediate ECG at triage in the ED. Women and the elderly with STEMI are particularly likely to present with atypical chief complaints such as dyspnea and weakness. Such patients experience significant delays in door-to-ECG time and treatment and have increased morbidity and mortality compared with patients who present with chest pain.[5,9–12] Despite numerous studies over the past decade documenting delays in treatment of patients with atypical acute MI presentations, the problem persists.

One option would be to perform an immediate ECG for all adults presenting to EDs regardless of their chief complaint. However, this approach would divert resources away from those patients who most need a rapid ECG. This approach is neither feasible nor cost-effective in busy EDs. Therefore, a simple approach is needed to systematically prioritize patients without chest pain during triage who should receive an immediate (eg, <10 minute) ECG. This same approach, if used by paramedics in the prehospital setting, could also increase the effectiveness of regional programs for acute cardiac care.

The objectives of the current study were to (1) describe the presenting symptoms of patients with STEMI by age and gender using an all-inclusive patient population of ED visits across a broad geographic area and (2) develop and validate a decision rule using age and chief complaint data to identify the subgroup of patients who should receive an immediate ECG upon ED arrival, particularly patients without chest pain. An objective of the rule was that it be simple to implement during triage and sensitive for STEMI, yet not result in an excessive number of ECGs being performed in the ED. Importantly, this rule was intended to prioritize which patients should receive an immediate ECG often before they are seen by a physician, rather than whether patients should receive an ECG at all as part of their emergency care.


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