• Broad, asymmetric, peaked T waves may be seen early in STEMI and often evolve into STEMI on serial ECGs

Which ischemic findings don’t make the cut?

Several other ECG findings of acute and subacute ischemia exist. The ACC consensus statement recognizes that ischemia may appear in other forms on ECGs, including Wellen’s syndrome, ischemic T wave inversion or ST-segment depression, and ST-segment elevation in lead aVR with multilead ST-depression. In a minority of these cases, OMI may be present.⁵ At this time, they recommend that patients with these ischemic ECG patterns be managed according to the 2014 AHA guidelines for the management of non-ST segment ACS.12 In other cases where the ECG may have ischemic findings not meeting previously named criteria, the document recommends serial ECGs, emergent echocardiogram, and/or emergent cardiology consultation.

What now?

Unfortunately, critical changes in guidelines often lack robust implementation plans to ensure that the frontline clinician can quickly integrate the guidelines into practice. Although the ACC consensus statement unequivocally recommends that patients with one of these four STEMI equivalents be treated as a STEMI, institutional and systemic barriers exist. As prehospital systems, hospital systems, and catherization lab teams work to respond to these new criteria, it is critical that emergency physicians integrate these criteria into clinical practice immediately because, after all, time is myocardium.

Dr. Westafer (@LWestafer) is assistant professor of emergency medicine and emergency medicine research fellowship director at the University of Massachusetts Medical School–Baystate and co-host of FOAMcast.

References

1. Null N, O’Gara PT, Kushner FG, et al. 2013 ACCF/AHA guideline for the management of ST-elevation myocardial infarction. Circulation. 2013;127(4):e362-e425.
2. Aslanger EK, Meyers HP, Smith SW. Time for a new paradigm shift in myocardial infarction. Anatol J Cardiol. 2021;25(3):156-162.
3. Meyers HP, Smith SW. Prospective, real-world evidence showing the gap between ST elevation myocardial infarction (STEMI) and occlusion MI (OMI). Int J Cardiol. 2019;293:48-49.
4. Meyers P, Weingart S, Smith S. The OMI Manifesto. Blog Post. http://hqmeded-ecg.blogspot.com/2018/04/the-omi-manifesto.html. Published April 1, 2018. Accessed November 13, 2022
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7. Sgarbossa EB, Pinski SL, Barbagelata A, et al. Electrocardiographic diagnosis of evolving acute myocardial infarction in the presence of left bundle-branch block. GUSTO-1 (global utilization of streptokinase and tissue plasminogen activator for occluded coronary arteries) investigators. N Engl J Med. 1996;334(8):481-487.
8. Smith SW, Dodd KW, Henry TD, Dvorak DM, Pearce LA. Diagnosis of ST-elevation myocardial infarction in the presence of left bundle branch block with the ST-elevation to S-wave ratio in a modified Sgarbossa rule. Ann Emerg Med. 2012;60(6):766-776.
9. Meyers HP, Limkakeng AT Jr, Jaffa EJ, et al. Validation of the modified Sgarbossa criteria for acute coronary occlusion in the setting of left bundle branch block: A retrospective case-control study. Am Heart J. 2015;170(6):1255-1264.
10. Ibanez B, James S, Agewall S, et al. 2017 ESC Guidelines for the management of acute myocardial infarction in patients presenting with ST-segment elevation: The task force for the management of acute myocardial infarction in patients presenting with ST-segment elevation of the European Society of Cardiology (ESC). Eur Heart J. 2018;39(2):119-177.
11. de Winter RJ, Verouden NJW, Wellens HJJ, Wilde AAM, Interventional Cardiology Group of the Academic Medical Center. A new ECG sign of proximal LAD occlusion. N Engl J Med. 2008;359(19):2071-2073.
12. Amsterdam EA, Wenger NK, Brindis RG, et al. 2014 AHA/ACC guideline for the management of patients with non-ST-elevation acute coronary syndromes: a report of the American College of Cardiology/American Heart Association task force on practice guidelines. Circulation. 2014;130(25):e344-e426.