Acute coronary syndrome (main)

For risk stratification see ACS - Risk Stratification

Background

Myocardial Infarction types

MI Types by Causation[2]

  • Type 1 - Spontaneous Myocardial Infarction
    • Atherosclerotic plaque rupture or intraluminal thrombus in one or more of the coronary arteries
  • Type 2 - Myocardial Infarction Secondary to an Ischaemic Imbalance
    • Condition other than CAD contributes to an imbalance between myocardial oxygen supply and/or demand
  • Type 3 - Cardiac Death Due to Myocardial Infarction
    • Suffer cardiac death with symptoms suggestive of myocardial ischaemia without elevated biomarkers
  • Type 4 - Myocardial Infarction Associated With Revascularization Procedure
    • 4a: Related to PCI
    • 4b: Related to Stent Thrombosis
  • Type 5 - Myocardial Infarction Related to CABG Procedure

Prognosis

Clinical Features

Risk of ACS

Clinical factors that increase likelihood of ACS/AMI:[3][4]

Clinical factors that decrease likelihood of ACS/AMI:[5]

  • Pleuritic chest pain
  • Positional chest pain
  • Sharp, stabbing chest pain
  • Chest pain reproducible with palpation

Gender differences in ACS

  • Women with ACS are less likely to be treated with guideline-directed medical therapies, less likely to undergo cardiac catheterization, and less likely to receive timely reperfusion.[6]
  • Men are more likely to report central chest pain, while women are more likely to report fatigue, dyspnea, indigestion, nausea/vomiting, palpitations and weakness[7], although some studies have found fewer differences in presentation[8]
  • Women are more likely to delay presentation. Additional factors associated with delay in seeking treatment include older age, Black or Hispanic race, and lower education and socioeconomic levels.[9]

Differential Diagnosis

Chest pain

Critical

Emergent

Nonemergent

Elevated Troponin

True Positive

False (Non-CAD) Positives

Evaluation

Workup

Evaluation

ACS Anatomical Correlation Chart

Ischemic Changes Location Coronary Artery
STE V1-V3, TWI

Q waves in V1-V3 over time

Septal Septal branch
STE V2-V4 Anterior LAD
STE I, aVL, V5, V6

STD inf leads

Lateral Circumflex
STE I, aVL, V2-6 Anterolateral LAD + circumflex = Left main or 2 critical lesions
STE II, III, aVF

STD in aVL (most common lead to see reciprocal change)

Inferior RCA

STE V1 (only lead looking at RV)
STE III > II (III more R facing)
STE V1 > V2, STE V1 + STD V2

Right ventricle RCA

STD in V1, V2, V3;
R>S in V1
Tall R waves in V1-V3 (Q waves on back of heart) w/ upright TWs

Posterior aka Inferolateral RCA (90%), LCA (10%)
STE avR>V1

Doesn't apply in SVT

Anterolateral Left Main

Management

Intensity of treatment should be based on ACS likelihood

Disposition

  • Admit
    • Ischemic ECG changes
    • Pacemakers
    • LBBB
    • Positive troponins
    • Abnormal vital signs
  • ACC/AHA rec need for provocative testing withing 72 hrs, consider admitting
  • For low risk (HEART) pts, may be better off discharge home with follow up[10]
    • Risk of MACE after neg ED work up 1/2422 vs Risk of preventable adverse event in hospital is 1/164

External Links

See Also

References

  1. AHA ACA - NSTEMI ACS Guidelines 2014 View Online
  2. Third Universal Definition of Myocardial Infarction http://circ.ahajournals.org/content/126/16/2020.full.pdf
  3. Body R, Carley S, Wibberley C, et al. The value of symptoms and signs in the emergent diagnosis of acute coronary syndromes. Resuscitation. 2010;81(3):281–286. PMID: 20036454
  4. Panju AA, Hemmelgarn BR, Guyatt GH, et al. The rational clinical examination. Is this patient having a myocardial infarction? JAMA. 1998;280(14):1256–1263. PMID: 9786377
  5. Swap CJ, Nagurney JT. Value and limitations of chest pain history in the evaluation of patients with suspected acute coronary syndromes. JAMA. 2005;294(20):2623–2629. PMID: 16304077
  6. Mehta LS, et al. Acute myocardial infarction in women: A scientific statement from the American Heart Association. Circulation. 2016; 133:916-947.
  7. Mehta LS, et al. Acute myocardial infarction in women: A scientific statement from the American Heart Association. Circulation. 2016; 133:916-947.
  8. Gimenez MR, et al. Sex-specific chest pain characteristics in the early diagnosis of acute myocardial infarction. JAMA Intern Med. 2014; 174(2):241-249.
  9. Mehta LS, et al. Acute myocardial infarction in women: A scientific statement from the American Heart Association. Circulation. 2016; 133:916-947.
  10. Weinstock MB, Weingart S, Orth F, VanFossen D, Kaide C, Anderson J, Newman DH. Risk for Clinically Relevant Adverse Cardiac Events in Patients With Chest Pain at Hospital Admission. JAMA Intern Med. 2015 Jul;175(7):1207-12.

Authors:

Ross Donaldson