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So let's talk about myocardial infarction.

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So the incident varies greatly with age and sex.

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NSTEMI is much more common than STEMI.

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It's much more common in men versus women.

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Typically, it occurs in patients who are over 45.

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Risk factors include all the things you

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shouldn't be doing or things you should be concerned about.

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So, smoking, hypertension, hyperlipidemia,

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diabetes, obesity, family history of heart disease.

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The traditional symptoms are crushing chest pain that may radiate to the left

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arm and into the jaw, tachycardia, shortness of breath, sweatiness,

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diaphoresis, syncopy, but more common in women, upper abdominal

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pain, which is not to say that it's exclusively in women.

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And so in this patient,

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we had someone who had vague abdominal pain, who was also constipated.

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But incidentally, we found that there was

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a myocardial infarction. In terms of our imaging guidelines and findings.

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CT with contrast is where you're going

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to get your biggest buck from things that we're going to see commonly in the ED.

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But the guidelines are really such that patients who have suspected ACS,

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but a negative EKG and troponins, this is who you should be thinking about.

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You may see a stenosis,

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you may see perfusion defects, and we saw the perfusion defect in this case.

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CT angiography does not have a significant difference from invasive coronary

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angiography in primary outcome in patients with stable chest pain.

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But the intermediate pretest probability

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of coronary disease does show a decreased complication rate.

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So, in terms of the pitfalls, just keep in mind that old infarct scars

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can be mistaken for acute infarct scars, and that can be differentiated by looking

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for wall thinning, which is more common in old infarcts,

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as well as those contour differences.

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Ultrasound can also be helpful, and just really broadly and just to move through

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this quickly, you will see diastolic dysfunction.

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So, wall motion abnormalities are things

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that you may begin to see. In areas of ischemia,

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you might not see the normal thickening

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during systolics. So during the contraction, it should thicken.

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And in abnormal scarred or ischemic

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tissue, you may not see that thickening take place.

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One of the pitfalls for ultrasound is

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that old infarcts will also display hypokinesis.

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But similar to CT,

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you're looking for that thinning of the wall and those contour changes.

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So, things to keep in mind with ultrasound. And finally with MRI,

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you're looking for myocardial edema that may be seen on T2-weighted images

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which may actually represent salvageable myocardium.

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So an opportunity for revascularization.

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Vasodilators during the MRI typically shows areas of enhancement

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of the myocardial, but that is blunted in ischemic tissue.

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So again, one of the pearls to keep in mind with MRI is late gadolinium

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enhancement can reveal old scarring in the myocardium.

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Here are a few references.