I hope this article improves the recognition of posterior MIs along with the other EKG patterns noted.

—Patricia Jo Schiff, MD, MMSc, FACEP

Re: “The Reperfusion Guidelines Finally Catch Up”

I read with interest the nice article by Dr. Westafer: “The Guidelines Finally Catch Up. New STEMI activation criteria.” As one of the founders of the new occlusion myocardial infarction (MI)—Non-Occlusion MI (OMI/NOMI) paradigm to replace the STEMI—non-ST elevation myocardial infarction (STEMI) paradigm, I am delighted that the American College of Cardiology/American Heart Association is de-emphasizing ST elevation in the diagnosis of occlusion. There are so many features of the ECG that are important. Among them, Dr. Westafer discusses posterior OMI; however, she propagates old dogma: that posterior OMI has a horizontal ST segment, a large R-wave, and an upright T-wave. We have proven all of this false in this paper: https://www.ahajournals.org/doi/pdf/10.1161/JAHA.121.022866.

We showed that acute posterior OMI may have a flat, upsloping, or downsloping ST segment, may have a small or large R-wave, may have inverted, biphasic, or upright T-waves. What matters is whether the ST depression is maximal in V1-V4 versus V5-6. The R-wave only enlarges after there is myocardial damage. The T-wave is more likely to be upright if there is prolonged infarction or reperfusion. The ST segment is downsloping in cases with a negative or biphasic T-wave.

—Stephen W. Smith, MD