A 64 y/o male with hx of DM and HTN presents with chest pain x several hours.
Q1. What does the EKG demonstrate?
Q2. What is the appropriate management?
A1. ST elevations in leads V2-V6, I, aVL with Q waves in leads V1 and V2.
A2. Immediate reperfusion therapy (PCI)
When ST elevations and Q waves appear in the same leads, this is referred to as an “evolving” ST elevation MI. This indicates that the MI has been ongoing for a couple of hours and some myocardium has already died. However, additional myocardium is still at risk and is potentially salvageable with reperfusion therapy. Pt’s with evolving MI’s are still candidates for emergent PCI.
Morphologic variations of ST segment elevation can be seen from the J (or junction) point at the end of the QRS complex to the apex of the T wave. This upsloping portion of the ST segment usually progresses as it elevates from flat to convex, domed or “tombstoned”; if flat, it is characteristically horizontal or oblique. At times the ST segment may be concave or scooped in its elevation with AMI. This morphology may progress to a convex shape or may stay the same throughout the infarction.
Q waves are generally representative of irreversible myocardial necrosis. Pathologic Q waves may emerge within the first hour of infarction but most commonly develop 8 to 12 hours into the infarction. It follows that ST segment elevation with concomitant Q waves does not preclude consideration of emergent reperfusion therapy.
(Kurz et al. Acute Coronary Syndrome. In Rosen’s Emergency Medicine, 8th Ed., Ch. 78)