The February article “Recognizing STEMI Equivalents” was great to see for someone like me who teaches cardiology for paramedics. However, one of its statements was inaccurate.
In the definition of LCA injury/triple vessel disease, the author incorrectly states that elevation in aVR and/or V1 with depression in eight leads is diagnostic. According to the fourth universal definition of MI published in Circulation in November 2018 on behalf of ESC/ACC/AHA/WHF, the requirement is now for depression in only six leads.
Author's reply: Thank you for your interest in my article. I chose to reference the material in the ESC Guidelines for the management of acute myocardial infarction in patients presenting with ST-segment elevation, which state that, “The presence of ST depression greater than or equal to 1 mm in eight or more surface (inferolateral ST depression), coupled with ST-segment elevation in aVR and/or V1, suggests multivessel ischemia or left main coronary artery obstruction, particularly if these patients present with hemodynamic compromise.”1
I felt this was a less-aggressive approach due to the probability some surface leads may only show subtle ST depression, where others may be more profound. I did read the fourth universal definition you referenced, which states that, “More profound ST-segment shifts or T-wave inversion involving multiple leads/territories are associated with a greater degree of myocardial ischemia and a worse prognosis. For example, ST-segment depression of 1 mm or greater in six leads, which may be associated with ST-segment elevation in leads aVR or lead V1 and hemodynamic compromise, is suggestive evidence of multivessel disease or left main disease.”2
Additionally, when I wrote the article I had researched other articles—one in the American Journal of Medicine titled “aVR ST-Segment Elevation: Acute STEMI or Not?” In the ECG analysis of patients with ST-segment elevation with multilead depression, those authors stated, “The average number of leads with ST depression was 7.3+1.4 mm with median amplitude of ST depression (largest value) of 2.0 mm (range: 2.0–3.0).”3 This particular study used multilead depression and not a hard number of leads such as six or eight, but the average number of leads of 7.3. Therefore, I used eight leads instead of six.
I know different agencies from state to state as well as regions within the state may use different criteria for diagnosing a STEMI, along with equivocal STEMI criteria. This is my rationale for the eight leads I referenced in my article.
1. 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): 119–77.
2. Thygesen K, Alpert JS, Jaffe AS, et al.; Executive Group on behalf of the Joint European Society of Cardiology (ESC)/American College of Cardiology (ACC)/American Heart Association (AHA)/World Heart Federation (WHF) Task Force for the Universal Definition of Myocardial Infarction. Fourth Universal Definition of Myocardial Infarction (2018). J Amer Coll Cardiol, 2018 Oct; 72(18).
3. Harhash AA, Huang JJ, Reddy S, et al. aVR ST Segment Elevation: Acute STEMI or Not? Incidence of an Acute Coronary Occlusion. Am J Med, 2019 May; 132(5): 622–30.
— Roger L. Layell, FP-C, CCP-C, CCEMT-P, NRP
Rare Disease? Just Ask!
I’m a medic and was recently diagnosed with hEDS (Ehler-Danlos hypermobility syndrome). I also have specific antibody deficiency, severe asthma that is being treated by monthly biologic injections, and thoracic spondylosis (arthritis in my spine).
I live with pain every day, and some days are better than others. If the pain in my hands is bad or my joints are stiff, I ask my partner to do the IV, and I always see if I can get help lifting patients even if they aren’t large. I used to be embarrassed to tell people about my conditions. Now I do so openly, but I also make sure they know I don’t want sympathy. If I need help, I ask for it, and I only go to another medical professional if I can’t do something on my own.
I’ve spent so much time studying my own conditions that I have cross-studied many other conditions as well, which helps with my patients I see. But as someone who lives with multiple chronic illnesses, if you aren’t familiar with something, please just ask. I won’t be upset if you don’t know what the conditions are or how to treat them, and I won’t mind if you need to take a second to Google it.