Myocardial Infarction: elevated cardiac biomarkers (aka troponin) with clinical evidence of acute myocardial ischemia (aka signs and symptoms, ECG changes, abnormal imaging, or coronary thrombosis at cath or autopsy).
Myocardial injury, unfortunately also can be abbreviated as MI, but not in our discussion. This term refers solely to cases where biomarker elevation is present without any other clinical evidence for ischemia.
STEMI definition from the European Society of cardiology:
ST elevation >1mm in two or more contiguous leads other than V2-V3
ST elevation in V2-V3
> 2.5mm in med < 40 yrs old
>2 mm in men > 40 yrs old
>1.5mm in woman, regardless of age.
MACE= Major Adverse Cardiovascular Event: including re-infarction, stroke, dysrhythmia, heart failure, cardiogenic shock, and death.
Part 2 : Why do we care?
In-hospital mortality rates are about the same for STEMI and NSTEMI, about 10%.
1-year fatality rate in NSTEMI is more than double that of STEMI, at about 25%
Part 3: Pathophysiology
Type 1 MI (Infarction) is caused by atherosclerotic plaque rupture.
Type 2 MI is the "mismatch" due to an imbalance in myocardial oxygen supply and demand. This can be the result of hypotension, tachycardia, sepsis, PE, etc.
Part 4: Pre-hospital care
Prehospital ECGs decrease time to intervention. (PCI) in STEMI
Early administration of aspirin decreases mortality and complications of MI (all types). (19), and is safe in the pre-hospital setting (20) - only 45% of get it during EMS transport, so room for improvement here (21)
Part 5: ED evaluation: Some of the interesting highlights
Radiation of pain to both arms or shoulders
Radiation of pain to right shoulder
Although teaching has been that women have atypical presentations, a 2016 study did not support it. However, it did find that elderly patients and those with diabetes may present atypically. (dyspnea, fatigue, nausea, or epigastric pain)
Past Medical History
Family and personal history of CAD
Other medical diagnoses
Illicit substance abuse
Age (CAD prevalence in age<40 is 1%, age >80 is 25%)
** HIV - find citing
8. Grunfeld C, Delaney JA, Wanke C, et al. Preclinical atherosclerosis due to HIV infection: carotid intima-medial thickness measurements from the FRAM study. AIDS (London, England). 2009;23(14):1841–9. [PMC free article] [PubMed] [Google Scholar]
9. Holloway CJ, Ntusi N, Suttie J, et al. Comprehensive cardiac magnetic resonance imaging and spectroscopy reveal a high burden of myocardial disease in HIV patients. Circulation. 2013;128(8):814–22. [PubMed] [Google Scholar]
Neurological neurologic deficit may point to aortic dissection
Friction rub may be heard
New murmur associated with papillary muscle rupture.
ECG. Patterns to know…
Troponin... you should get it
Imaging in the ED
CT angiography, CT PE, CCTA
Echocardiography - POC or formal
Part 6: Medications
Oxygen (if sat <90%)
Part 7: Revascularization
Immediate/urgent revascularization is recommended for all patients with NSTEMI who show signs of clinical instability, including refractory angina, sustained ventricular dysrhythmias, new or worsening heart failure, or shock (AHA class Ia recommendation; ESC class Ic recommendation). Otherwise, there is no clear benefit to immediate revascularization on all NSTEMI patients.
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