32 yo M with substernal chest pressure

Original case from Brandon Fainstad, MD.
Edits and graphics by Yilin Zhang, MD.


  • Practice interpreting ECGs


32 year old man developed substernal chest pressure and SOB while playing tennis at 1830. The symptoms did not resolve with rest. He took aspirin 182mg and asked his friend to take him to the ED. About 15 min after arriving in the ED his symptoms self-resolved. His PMH is notable for hypertension but does not take any medications. He smokes 1 ppd but denies any other substance use.

On exam, he is afebrile, HR 86, BP 165/82, RR 20, SpO2 96% RA. He is breathing comfortably, lung exam clear to ausculation bilaterally. His cardiac exam reveals RRR, no murmurs, skin is warm with good distal pulses with non-elevated JVP.

ECG – 2100
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How can you differentiate between benign early re-polarization (J point elevation) and STEMI?

What is the criteria for STEMI?

When do you want to get another ECG?

ECG – 2120 (20 min after initial ECG)
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Does this make you more or less worried?  What are your next steps in management? 


No interventions were done. More than an hour goes by before the subsequent ECG.

ECG – 2245
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Finally, a code STEMI was called, received the above listed medications and went to the cath lab with the following angiography.

Based on the ECG what vessel is likely involved and at what level is the occlusion?

Pre-PCI 23:35

Post PCI 23:43




  1. Mirvis GM & Goldberger AL. Electrocardiography. In: Mann DL, et al (eds.) Braunwald’s Heart Disease: A Textbook of Cardiovascular Medicine. Philadelphia, PA. Elsevier Saunders. 2015: 114-154.
  2. Ibanez J, 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.
  3. O’Gara PT et al. 2013 ACCHF/AHA Guideline for the Management of ST-Elevation Myocardial Infarcation: A Report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. Circulation. 2013; 127:e362-e425.