A 40 year old male without cardiac risk factors and with no h/o CAD presented with a few days of intermittent typical chest pain. He has a history of "reflux" and asthma. He seemed to be pain free during this first ED ECG, but he was unclear about it:
This ECG is typical not of acute inferior STEMI, but of old, or at least subacute STEMI: the T-waves are inverted and there are well-formed Q-waves. What about reciprocal ST depression in aVL? This is seen both in acute inferior STEMI and in "old inferior MI with persistent ST elevation," also known as "LV aneurysm morphology." For this reason, these two entities can be very difficult to differentiate. We have discussed anterior LV aneurysm frequently in the past. Though both have ST elevation, Anterior STEMI and anterior aneurysm are much easier to differentiate.
The initial troponin I returned at 0.075 (+), complicating the issue. Is it a NonSTEMI superimposed on old MI? If it were subacute STEMI, there would be a much higher troponin. So a bedside echo was done by the emergency physician. Here we see the parasternal short axis view, which gives a cross section of the LV, with the anterior wall closest to the transducer and the inferior/posterior wall farthest:
|Still picture at end systole: Narrow arrows show thin and akinetic inferior wall, compared to thick arrows which show a normal wall thickness in an area with good myocardial shortening (normal anterior wall motion).|
The patient was treated medically and admitted. The troponins peaked at a level consistent with NonSTEMI. Angiogram revealed severe 3 vessel disease with a chronically occluded right coronary artery. The patient went for bypass surgery. There was no evolution of ECG changes, nor resolution of ST elevation, confirming these were old findings.