EM@3AM – Acute Coronary Syndrome

Author: Erica Simon, DO, MHA (@E_M_Simon, EM Chief Resident, SAUSHEC, USAF) // Edited by: Alex Koyfman, MD (@EMHighAK, EM Attending Physician, UT Southwestern Medical Center / Parkland Memorial Hospital) and Brit Long, MD (@long_brit, EM Attending Physician, SAUSHEC, USAF)

Welcome to EM@3AM, an emdocs series designed to foster your working knowledge by providing an expedited review of clinical basics. We’ll keep it short, while you keep that EM brain sharp.

A 69 year-old male with a history of hypertension, hyperlipidemia, and smoking presents with pre-cordial chest pain radiating to his right upper extremity, associated with shortness of breath. The patient reports the onset of his symptoms one hour prior to arrival, while mowing his lawn. He characterizes his chest pain as an 8/10 “tightness” and notes nausea that “comes in waves.” ROS is negative for recent illness, travel, and hospitalization within the previous 90 days. The patient denies personal or familial history of DVT/PE.

 Triage VS: BP 157/98, HR 102, RR 22, T99.8°F Oral, SpO2 98% on room air

What diagnosis do you suspect? What’s the next step in your evaluation and treatment?

Answer: Acute Coronary Syndrome (ACS)^1-4

• ACS: Consists of unstable angina, NSTEMI, and STEMI
• Risk Factors: Hypertension, diabetes, dyslipidemia, tobacco use, family history of CAD (i.e. – CAD in a male primary relative younger than 55 years of age, or CAD in a female primary relative younger than 65 years of age), HIV/AIDS, SLE, cocaine use.¹
• Presentation: Chest pain or pressure radiating to the neck, jaw, or upper extremities; mid-epigastric pain, diaphoresis, nausea with or without emesis.²
  • Increased likelihood of acute MI:³
    • Chest pain with radiation to right arm or shoulder: positive likelihood ratio (+LR) 4.7; 95% CI 1.9-12
    • Chest pain with radiation to both arms or shoulders: +LR 4.1; 95% CI 2.5-6.5
    • Chest pain associated with exertion: +LR 2.4; 95% CI 1.5-3.8
•  Evaluation:
  • Focused H&P, serial EKGs, cardiac biomarkers, chest radiograph
    • Troponin I most sensitive marker of cardiac myocyte damage (positive in NSTEMI and STEMI).¹
•  Treatment:¹
  • Administer non-enteric coated, chewable ASA.
  • Antithrombotic therapy and/or anti-platelet therapy as appropriate per the diagnosis.
  • Nitrates to relieve chest discomfort (caution in the setting of inferior STEMI => perform R-sided EKG to rule out RV infarct,  a pre-load dependent condition).
  • Supplemental oxygen therapy for patients with shortness of breath, signs of acute heart failure, or cardiogenic shock.
•  Pearls:
  • Females, diabetics, and the elderly often present atypically.
  • Keep in mind there are numerous ACS mimics: aortic dissection, PE, pneumonia, pericarditis, myocarditis, pleurisy, PUD, etc.
  • Previous non-invasive cardiac stress testing does not rule out coronary artery disease.⁴

References:

1. Qazi M and Patel P. Acute Coronary Syndrome. In: Ferri’s Clinical Advisor 2017. Philadelphia: Saunders Elsevier, 2017: 25-29.e1.
2. Kumar A and Cannon C. Acute Coronary Syndromes: Diagnosis and Management, Part I. Mayo Clin Proc. 2009; 84(10): 917-938.
3. Swap C and Nagurney J. Value and limitations of chest pain history in the evaluation of patients with suspected acute coronary syndromes. JAMA. 2005; 294(20): 2623-2629.
4. Walker J, Galuska M, Vega D. Coronary disease in emergency department chest pain patients with recent negative stress testing. West J Emerg Med. 2010; 11(4): 384-388.

For Additional Reading:

EKG Findings in ACS:
http://www.emdocs.net/leftmainstemi/
http://www.emdocs.net/hyperacute-t-waves/
http://www.emdocs.net/ber-vs-anterior-stemi/

ST Elevation in aVR:
http://www.emdocs.net/r-e-b-e-l-em-st-segment-elevation-lead-avr-getting-much-respect-amal-mattu/

Risk Stratification:
http://www.emdocs.net/chest-pain-controversies-risk-stratification-stress-test-utility-part-1/
http://www.emdocs.net/chest-pain-controversies-coronary-cta-use-part-2/

Management of Low-Risk Chest Pain:
http://www.emdocs.net/r-e-b-e-l-em-management-and-disposition-of-low-risk-chest-pain/