Vignette: A confused elderly out in the street on a cold night.
Is this a STEMI?
Image digitized using PMCardio App
Because of wandering baseline and artifacts, it is difficult to know whether this is sinus rhythm or atrial fibrillation. What caught the eyes are those ST elevations in 2, 3, aVF and V3-V6. There seemed to be an extra wave after the S wave which makes the QRS look longer. The QT looked prolonged and T wave is long and irregular. This does not look the typical ST elevation in myocardial infarction (https://www.ekgrhythm.com/search/label/STEMI) .
Differentials could be early AMI, early repolarization, Brugada pattern, etc.
This wave or pattern is the Osborn wave (of hypothermia). Here is the screenshot of the description by J Osborn of the waves during his experimentation.
The original John Osborn report. - https://pubmed.ncbi.nlm.nih.gov/13114420/