A comatose patient with a carbon monoxide level over 50%

A young man had an accidental exposure to carbon monoxide (CO).  He was comatose and intubated and his initial Carboxyhemoglobin level was over 50%.An ECG is always recorded for CO toxicity.  This was his ECG.  It was shown to me with worry for ischemic ST elevation, which is certainly possible from severe CO toxicity, or concomitant ACS.  In fact, there is laboratory evidence that CO toxicity increases Platelet –neutrophil aggregates and plasma myeloperoxidase (MPO) concentration and thus may precipitate ACS (though this is by no means clinically proven).  Intravascular Neutrophil Activation Due to Carbon Monoxide PoisoningWhat do you think of this ECG?My interpretation was that this was all normal variant ST Elevation.Inferior STE: there are prominent J-waves in all leads.  There is no reciprocal ST depression in aVL.Anterior STE: Prominent J waves and high QRS amplitudes.If we use theLAD-normal variant formula, we get:QTc = 436 ms R-wave V4 = 13 mm, QRS V2 = 21 mm, STE at 60 ms after J pt in V3 = 2.5Formula value = 18.7.  This is suggestive of LAD occlusion.  However, the variable which most contributes to this is the QTc of 436 ms, which is quite long and skews the result of the formula to LAD occlusion.  For comparison, if the QT were an average of that of LAD occlusion (420 ms) vs. Normal variant (390 ms) from our study, the QTc would be 405 ms and the formula value would be 17.06, which i...
Source: Dr. Smith's ECG Blog - Category: Cardiology Authors: Source Type: blogs