This post contains links to and excerpts from two outstanding Emergency Medicine Cases posts:
- Jesse MacLaren on ECG Cases – missed ischemia and pitfalls of “normal” computer ECG interpretations (5:20 – 9:23) [Link is to the shownotes and podcast] of EM Quick Hits 9 Burn Blister Debridement, ECG Cases, Compartment Syndrome, Pediatric Asthma, Spinal Trauma, Motivational Interviewing P2 from Emergency Medicine Cases. October, 2019
- Teaching Images [Link is to the post] of ECG examples and flow charts of Acute Coronary Syndrome from Dr. Smith’s ECG Blog
- ECG Cases 1: Missed Ischemia – Never Trust the ECG Computer Interpretation [Link is to the post] from Emergency Medicine Cases. September, 2019.
What follows is Resource (1) in its entirety:
Missed ischemia with “normal” ECG computer interpretation
Never trust the ECG computer interpretation, even if it says “normal,” because:
- Ischemic morphology*: the computer focuses on ST segment elevation, and can miss ischemic ST-T wave morphology—including straight or convex ST segments, terminal T wave inversion, down-up T waves, hyperacute T waves, deWinter T waves, and inverted U waves
- Dynamic change*: the computer interprets each ECG in isolation, and can’t compare to prior or repeat ECGs (which is critical in a dynamic process like coronary occlusion)—so it can miss subtle changes, including pseudonormalization of ST segments or T waves
- STEMI criteria*: computer interpretation is based on STEMI criteria, which has limited sensitivity for identifying acute coronary occlusion—so it can miss subtle ST elevation (which may be significant in small amplitude QRS complexes), ST depression in aVL (which is very sensitive for inferior MI), and subtle signs of LAD occlusion like terminal QRS distortion.