We are told that this ECG was obtained from an elderly man with diabetes and chronic renal failure. There is no mention of chest pain … For discussion purposes, the findings (prior to knowing that serum K+ = 6.3 mEq/L) show baseline artifact — sinus rhythm — tall, peaked and pointed T waves especially in V2, but also in lead V3 — and some ST-T wave depression in leads III, aVF.

Interpretation would be MUCH more challenging if the history was of a patient with new-onset chest pain! In that case, one would have to consider whether the prominent T waves in leads V2,V3 seen here in association with ST-T depression in leads III, aVF might represent early DeWinter T Waves with reciprocal inferior st-t wave changes … That said, the KEY features to me are: i) How NARROW the base of the T wave is in lead V2; and ii) That this patient does NOT apparently have any chest pain, but instead has diabetes + renal failure. Given that, my strong suspicion would be Hyperkalemia, as was shown to be the case here (K+ = 6.3).

Keep in mind the following: i) There is LOTS of artifact on this tracing. For example, the 2nd ST segment in lead aVL is clearly concerning, but the 3rd and 4th are not. Artifact can make it VERY difficult to intelligibly interpret ECGs. ii) ST-T wave changes of Hyperkalemia are usually much more diffusely seen than they are here … so this tracing is in no way definitive for hyperkalemia. iii) The ECG changes of hyperkalemia are SUPERIMPOSED on whatever else was previously present in the baseline ECG — and whatever else may be going on. Thus, an acute stemi could be masked by hyperkalemia. And combination of T inversion from ischemia + T wave peaking from hyperkalemia could produce “pseudo-normalization”, and a surprisingly unremarkable tracing … It would indeed be interesting to know what this patient’s baseline tracing looked like.

P.S. I distinctly remember several patients we had with a long history of renal failure plus frequent bouts of dehydration and other conditions that predisposed them to periodic episodes of hyperkalemia. For some of these patients, I could INSTANTLY tell by looking at their ECG that, “T waves in a few leads were getting more peaked again — so time to check serum K+”. Relative volume contraction in sensitive elderly patients was a common precipitant of clinical hyperkalemia in such patients. Perhaps that was the case here … ?