A middle-aged man with severe syncope, diffuse weakness

p.p1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 11.0px Helvetica; background-color: #fefefe}A middle-aged male diabetic who is otherwise healthy was found unconscious by his wife, with incontinence.  He quickly awoke but was too weak to stand.  Initial vitals by EMS were BP 100/50 with pulse of 80 and normal glucose.  He remained weak and somnolent, and without focal neurologic abnormality.  He recovered full consciousness, but still felt weak and " not normal. "  There was a prehospital ECG:What do you think?He arrived in the ED and had this ECG recorded:This one was sent to me for my opinion.  I looked at it without any clinical information.What do you think?I wrote back that this is diagnostic ofhypokalemia.  It turned out the K was2.6 mEq/L.Why did I say this?There isscooped ST depression in multiple leads, very typical of hypokalemia: I, II, aVL, V4-V6.There arelarge U-waves.  Look particularly in V1 and V2.  This results in the appearance of down-up T-wave in V2; however, if it is a T-wave, resulting QT interval would be impossibly long.  Thus, it is a large U-wave, and the apparent QT interval is a QU interval. Look directly above at V1 and you can see the U-wave clearly.Such downsloping ST depression in V2 may frequently be misinterpreted as posterior STEMI (reciprocal to ST elevation of the posterior wall).Case continued:The patient had no chest pain or SOB.  His initial lactate returned at 5.0 m...
Source: Dr. Smith's ECG Blog - Category: Cardiology Authors: Source Type: blogs