Acute Coronary Syndromes Algorithm

Understanding how to effectively manage Acute Coronary Syndrome (ACS) is crucial for healthcare providers. This algorithm breaks down the key steps in assessing, treating, and managing patients presenting with signs of ischemia or infarction.

EMS Assessment, Care, and Hospital Preparation

1. Monitor & Support ABC’s (Airway, Breathing, Circulation)
   • Ensure the patient’s airway is clear, assist with breathing if needed, and support circulation.
   • Be prepared to perform CPR or use a defibrillator if necessary.
2. Administer Aspirin
   • Give the patient 160 to 325 mg of aspirin to chew, which helps prevent further clotting.
   • Chewing aspirin rather than swallowing whole allows it to act more quickly, potentially within 5 minutes.
3. Obtain 12-Lead ECG: Interpret/Transmit
   • Perform a 12-lead ECG to check for ST elevation. Note the time of onset and first medical contact.
   • Transmit ECG results to the hospital if possible.
   • Early transmission of ECG results can reduce door-to-balloon times, significantly improving outcomes for STEMI patients.
4. STEMI Response
   • If a STEMI is suspected, notify the hospital to prepare for immediate intervention.
5. Complete Fibrinolytic Checklist
   • Use a checklist to determine if the patient is eligible for prehospital fibrinolysis (clot-busting medication).

Concurrent ED Assessment (<10 Minutes)

1. Check Vital Signs & Oxygen Saturation
   • Continuously monitor the patient’s vital signs and oxygen levels.
2. Establish IV Access
   • Insert an IV line for administering medications and fluids.
3. Brief History & Physical Examination
   • Conduct a quick history and physical exam, focusing on cardiovascular risk factors and symptoms.
   • Atypical presentations of ACS, such as gastrointestinal symptoms or jaw pain, are more common in women and the elderly.
4. Obtain Initial Cardiac Markers and Labs
   • Draw blood for initial cardiac markers (like troponins) and other relevant labs.
5. Portable Chest X-Ray (<30 Minutes)
   • Perform a portable chest x-ray to evaluate the heart and identify any complications.

Immediate ED General Treatment

1. Start Oxygen
   • Administer oxygen at 4 L/min and adjust to keep oxygen saturation above 90%.
2. Administer Aspirin
   • Ensure aspirin has been given. Administer 160 to 325 mg if not already done by EMS.
3. Administer Nitroglycerin
   • Provide sublingual or spray nitroglycerin to relieve chest discomfort unless contraindicated.
   • Nitroglycerin not only alleviates pain but also helps diagnose ACS, as relief with nitroglycerin is often indicative of cardiac origin.
4. Administer Morphine IV
   • Give IV morphine if discomfort persists despite nitroglycerin.
   • Morphine can help reduce the heart’s oxygen demand by lowering anxiety and pain, though its use should be balanced with caution as it may mask symptoms.

ECG Interpretation

• ST-Elevation MI (STEMI)
  • Characterized by ST elevation or new left bundle branch block (LBBB), strongly indicating injury.
  • Actions:
    • Begin adjunctive therapies as needed.
    • Do not delay reperfusion strategies.
    • If Symptoms <12 Hours:
      • Aim for door-to-balloon (PCI) inflation within 90 minutes.
      • Aim for door-to-needle (fibrinolysis) within 30 minutes.
    • If Symptoms >12 Hours:
      • Evaluate reperfusion need based on patient criteria and center capabilities.
    • Rapid reperfusion is critical; every 30-minute delay in reperfusion increases the one-year mortality by 7.5%.
• High-Risk Non-ST-Elevation ACS
  • Characterized by ST depression or dynamic T-wave inversion, strongly indicating ischemia.
  • Actions:
    • Consider early invasive strategy for:
      • Refractory chest discomfort.
      • Persistent ST deviation.
      • Ventricular tachycardia.
      • Hemodynamic instability.
      • Signs of heart failure.
    • Start adjunctive therapies (e.g., nitroglycerin, heparin).
    • High-sensitivity troponin assays can detect myocardial injury more accurately and earlier than standard assays.
• Low/Intermediate-Risk ACS
  • Characterized by normal or nondiagnostic changes in the ST segment or T wave.
  • Actions:
    • Consider admission to an ED chest pain unit or appropriate bed for further monitoring and possible intervention.
    • Stress testing or advanced imaging (like coronary CT angiography) can help stratify risk and guide management for these patients.

Key Takeaways

Effective ACS management requires prompt recognition and timely intervention. Following these structured steps ensures that healthcare providers can offer the best care, improving patient outcomes. Continuous monitoring, appropriate medication administration, and swift ECG interpretation are vital components of ACS management. Prioritizing rapid reperfusion strategies for STEMI patients and closely monitoring high-risk non-ST-elevation ACS patients are essential actions. Low/intermediate-risk ACS patients should be observed and assessed further.