Divulge the Bulge
Brian Smith, DO
You get a notification from EMS: ETA 5 minutes
76 y.o. M with a PMH of MI 1 year ago s/p stent placement, CHF with EF 20-25%, HTN, HLD, DM, AAA s/p mesh placement, COPD complaining of chest pain. Prior to patient’s arrival, this ECG is sent by EMS:
The patient arrives and actually appears well. He’s sitting comfortably in the stretcher, VS: BP: 160/80, HR: 60, RR 16, Temp 36.7, SPO2 95% on RA, FS 200. You obtain more history while getting the patient on the Zoll, establishing access, and drawing labs:
The patient reports crushing, substernal chest pain that started 1 hour prior to arrival and that it feels similar to his prior MI. He denies shortness of breath, nausea, diaphoresis, or other complaints. He took 324mg aspirin en route to ED with resolution of symptoms. He states he is currently asymptomatic.
Question: What are your next steps? What do you think this ECG most likely represents?
Code STEMI is activated, and of course it is! Given the story and THAT ecg, who wouldn’t activate the cath lab? But what if I told you this ECG is not suggestive of ACUTE ischemia….
You obtain a repeat ECG, which is unchanged from the ECG provided by EMS. You then review his chart and see he presented to the ED 3 months prior for similar symptoms and see his ECG obtained at the time (right).
His current ecg is on the left for comparison
His old ECG looks worse, doesn’t it? The ST elevations AND Q wavs are more pronounced in all of the precordial leads in his prior ECG. So what is going on here exactly?
What should we do next? How about trying to take a look with ultrasound?
Well this confirms our diagnosis! This ecg was not a STEMI; but rather, suggestive of a common post-MI complication. Do you recognize that thing bulging from the left ventricle?
Answer: Left Ventricular Aneurysm
OK, but how do I tell if a patient with an LV aneurysm is having an acute ischemic event?
Factors to consider
Clinical Context
Repeat ECG - are there dynamic changes?
Comparison to prior - are the ST elevations more pronounced on new ECG?
Reciprocal depressions - suggests acute MI
T:QRS Ratio
<0.36 in ALL precordial leads favors LV aneurysm
>0.36 in ANY precordial lead favors acute MI
Note persistent STEs and “pathological Q Wave” in V1-V3. However, T:QRS ratio is >0.36 in V3 - suggesting acute MI
Take Home Points:
Persistent ST elevations and deep “pathologic” Q waves post-MI are signs of left ventricular aneurysm
Dynamic changes, worsening ST elevations, and/or QRS:T ratio >0.36 suggest acute ischemia
When concerned for acute ischemic event: obtain repeat ECG and compare to prior when available