A middle-aged male presented with acute chest pain:

There is sinus rhythm. There is LVH by voltage in aVL, with what may appear to be secondary repolarization abnormalities (so-called “LVH with strain”, but this is a misnomer because it implies ischemia.  “LVH with secondary repolarization abnormalities” is more appropriate). It has the “hockey stick” morphology typical of LVH with secondary repolarization abnormalities. What do you think?

Here is the ECG of another middle-aged male with acute chest pain:

It is similar, but notice how the T-waves are not nearly as proportionately large as in the above ECG. What do you think?

The bottom ECG is that patient’s baseline LVH.

The top ECG is LVH with superimposed inferior acute MI.   The T-waves (both upright and negative ones) are far too large in proportion to the QRS.  There is also a concordant T-wave in lead II, and ischemic appearing biphasic T-waves in V4-V6, with a flattened ST segment in V3, all suggesting posterior and lateral involvement.

Notice also the ischemic biphasic T-waves in V4 and V5.

Technically, it is not “STEMI” because the ST elevation at the J-point is less than 1 mm.

But it is an OMI!!

This (top) ECG was missed by several interpreters and the patient had very delayed reperfusion therapy.  

The culprit was 100 % thrombotic occlusion of the mid RCA.  The peak troponin I was 47 ng/ml (very high).  There was a regional wall motion abnormality in the inferior and posterior walls.   The LAD was not involved.

The patient was discharged with a diagnosis of NonSTEMI.

There actually was a previous ECG for comparison, which proves the point.  Here it is:

Very different from LVH with superimposed inferior STEMI.

Here is the post-PCI ECG:

Notice inferior reperfusion (inverted) T-waves Notice precordial large T-waves (posterior reperfusion T-waves) Notice lateral reperfusion T-waves. These are “Wellens’ waves” of inferior, posterior, and lateral walls.

Learning point

Know the T-wave to QRS proportions in LVH vs. LVH with superimposed MI.