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Acute Coronary Syndrome Immediate Management

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Acute Coronary Syndrome Immediate Management, Myocardial Infarction Assessment, Ischemic Chest Pain Management, Immediate Myocardial Infarction Management, Immediate MI Management, Acute Chest Pain Approach

  • See Also
  1. Chest Pain
  2. Cardiac Risk Factors
  3. Angina
  4. Angina Diagnosis
  5. Unstable Angina
  6. Spontaneous Coronary Artery Dissection
  7. TIMI Risk Score
  8. Bosner Chest Pain Decision Rule
  9. Acute Coronary Syndrome
  10. Acute Coronary Syndrome Adjunctive Therapy
  11. High Risk Acute Coronary Syndrome Management
  12. Moderate Risk Acute Coronary Syndrome Management
  13. Low Risk Acute Coronary Syndrome Management
  14. Myocardial Infarction Stabilization
  15. Serum Cardiac Markers
  16. Electrocardiogram in Myocardial Infarction
  17. Echocardiogram in Myocardial Infarction
  18. Goldman Criteria for ICU Chest Pain Admission
  • History
  • Targeted Brief
  1. Duration of pain
  2. Prior Myocardial Infarction
  3. Cardiac Risk Factors
  4. Thrombolytic Contraindications
  • Exam
  • Targeted Brief
  1. Signs of right or left sided Heart Failure
  2. New murmur or pericardial rub
  3. Assess tissue perfusion, systemic Blood Pressure
  4. Asymmetry of peripheral pulses
  • Labs
  1. Basic chemistry panel
  2. Complete Blood Count
  3. Troponin I
  • Diagnostics
  1. Electrocardiogram
    1. Obtain within 5-10 minutes of patient arrival (and repeat serially)
    2. See EKG in Acute MI
    3. See Evaluation: Electrocardiogram below
  • Imaging
  1. Chest XRay
    1. Obtain within 30 minutes (typically portable)
  2. Echocardiogram (consider if no delay)
    1. See Echocardiogram in Acute MI
    2. See Echocardiogram for bedside technique
    3. Evaluate for additional emergent angiography indications
      1. Acute wall motion abnormality
      2. Ejection fraction <40%
    4. Evaluate Chest Pain differential diagnosis (e.g. Pericardial Effusion)
  • Evaluation
  • Immediate Assessment
  1. ABC Management
  2. Mnemonic: IV-O2-Monitor
    1. Vitals with Oxygen Saturation
    2. Start Intravenous Access
    3. Cardiopulmonary monitor
  3. Consider Differential Diagnosis
    1. See Chest Pain
  1. Precautions
    1. Developing Q Waves do not modify the reperfusion strategy
    2. Evaluate the Electrocardiogram carefully (ischemic changes are commonly missed)
      1. Hyperacute T Waves precede ST Elevation
      2. More than 25-30% of NSTEMI patients have complete coronary Occlusion (benefit from emergent PCI)
        1. Khan (2017) Eur Heart J 38(41): 3082-9 +PMID:29020244 [PubMed]
        2. Koyama (2002) Am J Cardiol 90(6): 579-84 +PMID:12231080 [PubMed]
    3. Perform serial EKGs
      1. EKG is non-diagnostic in 11% of STEMI patients (and Troponin Is initially normal in 55% of cases)
      2. EKG is normal in 5-28% of Acute Coronary Syndrome patients
      3. EKG converts from non-diagnostic to STEMI in 33% by 30 min, 50% by 45 min, and 75% by 90 min
      4. Riley (2013) Am Heart J 165(1): 50-6 [PubMed]
    4. Observe for right sided inferior MI
      1. Inferior STEMI or Posterior STEMI (V1-V2 ST Depression and right sided EKG with V4 ST Elevation)
      2. Avoid Nitroglycerin and infuse crystalloid to maintain adequate systolic Blood Pressure
    5. Observe for posterior MI
      1. Consider leads V7 to V9 (left lateral and Scapular leads) to evaluate for ST Elevation (0.5 mm may be sufficienct critieria)
    6. ST Elevation criteria in leads V1-V2 varies by age and gender
      1. Men age <40 years old
        1. V1-V2 ST Elevation >2.5 mm
        2. Accounts for Early Repolarization in young men
      2. Men age >40 years old
        1. V1-V2 ST Elevation >2 mm
      3. Women
        1. V1-V2 ST Elevation >1.5 mm
    7. Consider other high risk findings
      1. Biphasic or Deep T Wave Inversion in V2, V3 (Wellen's Syndrome)
        1. High risk for left anterior descending artery ischemia and Anterior Wall Myocardial Infarction
      2. Hyperacute T Waves with J Point Depression (De Winter T Waves)
        1. J Point depression with upsloping ST Segment AND
        2. Tall, prominent, hyperacute precordial T Waves
          1. Hyperacute T Waves also seen in Hyperkalemia, STEMI without J Point depression
      3. ST Depression >1 mm in 8 or more leads (esp I, II, V4-6) AND ST Elevation in aVR or V1
        1. Suggests multi-vessel ischemia or left main obstruction
  2. High Risk: Myocardial Infarction Protocol
    1. ST Elevation MI (Q-Wave MI)
    2. ST Elevation MI equivalent
      1. Posterior Myocardial Infarction (ST depression in V1, V2)
        1. Obtain a right sided EKG and evaluate for ST Elevation in right-sided V4
        2. Obtain leads V7 to V9 (left lateral and Scapular leads) to evaluate for ST Elevation (0.5 mm may be sufficienct critieria)
      2. New (or presumed new) Left Bundle Branch Block
        1. See High Risk Acute Coronary Syndrome Management for details
        2. Significant caveats to whether LBBB is a STEMI Equivalent
        3. See Sgarbossa Criteria
  3. Moderate Risk: Myocardial Ischemia Protocol
    1. Non-ST elevation MI (Non-Q-Wave MI)
    2. ST depression or dynamic T Wave Inversion
    3. High Unstable Angina Risk
  4. Low Risk: Non-diagnostic Electrocardiogram Protocol
    1. Absent ST Segment or T Wave changes on EKG
    2. Low Unstable Angina Risk
  • Management
  • Immediate
  1. Aspirin
    1. Non-enteric coated Aspirin 324 mg orally
      1. Typically administered as four 81 mg chewable Aspirin
      2. Large, high quality study demonstrated 1 more patient survived for every 42 treated for STEMI (NNT=42)
      3. Number needed to harm: 167 (minor bleeding not requiring transfusion, and no increased Intracranial Hemorrhage)
      4. Newman in Herbert (2013) EM:Rap 14(1): 4
      5. (1988) Lancet 332(8607): 349-60 [PubMed]
    2. Aspirin sensitivity
      1. Aspirin Rash: Give Aspirin with Diphenhydramine (e.g. 12.5 mg IV)
      2. Aspirin Anaphylaxis or Angioedema: Give Clopidogrel (Plavix) 75 mg or Ticagrelor (Brilanta) 90 mg instead of Aspirin
      3. PUD History: Give Aspirin with H2 Blocker (e.g. Ranitidine)
  2. Nitroglycerin
    1. Nitroglycerin 0.4 mg sublingual (tablet or spray)
    2. Low threshold to switch to Nitroglycerin Drip
      1. Start if higher suspicion for Acute Coronary Syndrome
    3. Nitroglycerin Paste 1 inch (consider starting with 1/2 inch)
      1. Eratic absorption limits use in Acute Coronary Syndrome
    4. Exercise caution
      1. Nitroglycerin is contraindicated in Aortic Stenosis, Pulmonary Hypertension, Hypotension, PDE5 Inhibitor
      2. Inferior Myocardial Infarction or posterior Myocardial Infarction (risk of right sided Myocardial Infarction)
        1. Risk of severe, refractory Hypotension
        2. Obtain Right sided EKG to exclude right sided Myocardial Infarction
        3. Secure IV Access and hang IV crystalloid in case of Hypotension
  3. Oxygen (if indicated)
    1. Deliver by Nasal Cannula at 2-4 liters per minute if Hypoxia (Oxygen Saturation <90-92%)
    2. Empiric oxygen without Hypoxia may increase coronary vascular resistance
  4. Morphine Sulfate
    1. Part of Mnemonic: "MONA" greets all patients
    2. IV 2-5 mg every 5-30 min prn
    3. Pain not relieved with 3 Sublingual Nitroglycerins (AND Nitroglycerin Drip)
    4. Morphine is an adjunct only in Chest Pain control (Nitroglycerin is the primary medication)
      1. Worse outcomes when Morphine is used in place of Nitroglycerin
  • Management
  • Approach
  1. Cardiology Consultation (immediately in high risk Acute Coronary Syndrome)
  2. Consider Acute Coronary Syndrome Adjunctive Therapy
  3. Risk stratify
    1. High Risk Acute Coronary Syndrome Management
    2. Moderate Risk Acute Coronary Syndrome Management
    3. Low Risk Acute Coronary Syndrome Management
  4. Indications to transfer to PCI Center (catheter lab)
    1. STEMI (emergent transfer)
    2. Unstable Angina or NSTEMI (See NSTE-ACS Protocol)
      1. Elevated Troponin
      2. New ST segment Depression
      3. Cardiogenic Shock
      4. Severe Left Ventricular Dysfunction or Acute Heart Failure
      5. Recurrent or persistent rest Angina despite intensive medical therapy
      6. New or worsening Mitral Regurgitation
      7. New Ventricular Septal Defect
      8. Hemodynamic instability
      9. Sustained Ventricular Arrhythmia
      10. Recent Percutaneous Coronary Intervention in last 6 months
      11. Prior Coronary Artery Bypass Graft
      12. High risk score (e.g. TIMI Score, GRACE Score)
  • References
  1. Velasco, Lee, Chandra (2019) Crit Dec Emerg Med 33(1): 3-10
  2. Orman and Mattu in Herbert (2017) EM:Rap 17(7): 6-7
  3. Swaminathan and Mattu in Herbert (2018) 18(9): 11
  4. (2000) Circulation 102(suppl I):I172-203 [PubMed]
  5. Ibanez (2018) Eur Heart J 39(2): 119-77 +PMID:28886621 [PubMed]