What is the standard of care for Emergency Medical Services (EMS) personnel treating a patient with suspected myocardial infarction (heart attack)?

Standard of Care for EMS Personnel Treating Suspected Heart Attack Patients

EMS personnel should immediately administer 162-325 mg of chewed aspirin to patients with suspected heart attack, perform a 12-lead ECG, and rapidly transport the patient to an appropriate facility capable of providing definitive care. 1

Initial Assessment and Management

Immediate Actions

• Perform rapid assessment of vital signs and cardiac rhythm
• Be prepared to provide CPR and defibrillation if needed 1
• Administer oxygen only if the patient is:
  • Dyspneic
  • Hypoxemic (O₂ saturation <94%)
  • Shows obvious signs of heart failure 1
• Titrate oxygen to maintain saturation ≥94% 1

Medication Administration

• Aspirin administration:
  • Give 162-325 mg non-enteric coated aspirin to be chewed 1
  • Contraindications: aspirin allergy, active/recent gastrointestinal bleeding 1
  • This reduces mortality in ACS by 23% 2
• Nitroglycerin administration:
  • Administer up to 3 doses of sublingual nitroglycerin at 3-5 minute intervals 1
  • Contraindications: systolic BP <90 mmHg or 30 mmHg below baseline, right ventricular infarction, PDE-5 inhibitor use within 24-48 hours 1, 3
  • Use extreme caution with inferior STEMI due to possible right ventricular involvement 1
• Pain management:
  • Administer IV morphine for persistent chest pain unresponsive to nitroglycerin 1
  • Use caution with morphine in unstable angina/NSTEMI due to association with increased mortality 1

ECG and Triage Decisions

• Perform and evaluate 12-lead ECG on all patients with suspected heart attack 1
• If ECG shows evidence of STEMI:
  • Review reperfusion checklist
  • Relay ECG and findings to receiving hospital 1
  • Consider direct transport to PCI-capable facility if:
    • First medical contact to balloon time <90 minutes
    • Transport time <30 minutes 1
  • For patients <75 years with cardiogenic shock, transport to facilities capable of rapid revascularization within 18 hours of shock onset 1

Common Pitfalls and Special Considerations

• Aspirin administration gaps: Despite clear guidelines, studies show only 45.4% of eligible patients receive aspirin from EMS providers 2. Ensure consistent administration to all eligible patients.
• Nitroglycerin contraindications: Avoid in right ventricular infarction, hypotension, and recent PDE-5 inhibitor use 1.
• Oxygen therapy misconceptions: Routine oxygen administration is not supported by evidence for uncomplicated ACS. Only administer when indicated by hypoxemia or respiratory distress 1.
• Delayed ECG interpretation: Rapid ECG acquisition and interpretation is critical for determining appropriate destination hospital and treatment pathway 1.
• Failure to pre-notify receiving facility: Early notification allows hospitals to prepare for immediate intervention upon patient arrival 1.

Quality Improvement Considerations

• All EMS systems should have quality improvement programs to ensure compliance with protocols 1
• EMS providers should receive ongoing training in ECG interpretation and STEMI management 1
• Dispatch centers should have medically trained personnel using standardized protocols 1, 4
• Consider implementing dispatcher-directed aspirin administration protocols for patients awaiting EMS arrival 1, 4

By following these evidence-based protocols, EMS personnel can significantly reduce morbidity and mortality in patients experiencing acute myocardial infarction through early intervention and appropriate triage to definitive care.