An ST-elevation myocardial infarction (STEMI) is a heart attack in which a coronary artery is fully blocked, and more heart muscle dies every minute. EMS can find it on a 12-lead ECG, alert the hospital and bring the patient straight to the cath lab, which shortens the time to open the artery.
Key symptoms
- Pressure, squeezing or heaviness in the chest for more than a few minutes
- Pain spreading to the arm, jaw, neck or back
- Shortness of breath, sweating and nausea
- Only weakness or fatigue, more often in women, older adults and people with diabetes
- Lightheadedness or fainting
What you find on exam
- Vital signs, focusing on blood pressure and heart rate
- Skin: pale, cool and sweaty
- Lung sounds for crackles of heart failure
- Signs of shock or right ventricular infarction
- Rhythm monitoring for dangerous arrhythmias
Tests
- 12-lead ECG within 10 minutes of first contact
- Right-sided leads (V4R) when there is inferior ST elevation
- Repeat ECG if the first is not diagnostic and symptoms continue
- Send the ECG to the hospital if your system allows
Treatment basics
- Aspirin 162 to 325 mg chewed unless allergic
- Nitroglycerin for pain if systolic pressure is 90 mmHg or more, with no right ventricular infarction or recent erectile dysfunction drug
- Oxygen only if saturation is below 90 percent
- STEMI alert and direct transport to a PCI center, aiming for first contact to balloon in 90 minutes or less
- Fentanyl for pain if needed; IV access and defibrillator pads ready
Red flags
- Low blood pressure or cardiogenic shock
- Ventricular tachycardia or fibrillation
- New slow heart rate or heart block with inferior STEMI
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Related guides
Sources: NASEMSO National Model EMS Clinical Guidelines; NREMT psychomotor skill sheets (EMT and Paramedic); AHA Guidelines for CPR and ECC. Written by Making Synapses. Making Synapses is not affiliated with these organizations.