Show Notes

 

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Emergency Department management of Non-St Segment Elevation Myocardial Infarction, by Drs Julianna Jung and Sharon Bord.

Chest pain is the second most common complaint

Over 6.4 million visits to US EDs annually include chest pain.

25% will be diagnosed with ACS

1/3 will have STEMI, 2/3 NSTEMI.

Guidelines reviewed include those from:

AHA/ACC

ACEP

European Society of Cardiology

In addition to reviewing the primary literature each of them used as a basis for their recommendations.

 

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Part 1: Definitions

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

History

Diaphoresis

Vomiting

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

Tobacco use

Illicit substance abuse

Age (CAD prevalence in age80 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]

** Cancer with hx of radiation to the chest

Exam

Neurological neurologic deficit may point to aortic dissection

Friction rub may be heard

New murmur associated with papillary muscle rupture.

Diagnostics

Telemetry

ECG. Patterns to know…

Troponin... you should get it

Scoring systems

Heart Score

Grace

TIMI

Imaging in the ED

CXR

CT angiography, CT PE, CCTA

Echocardiography - POC or formal

Part 6: Medications

Oxygen (if sat