An NSTEMI is a heart attack in which a narrowed coronary artery cuts blood flow enough to damage muscle, shown by a rising troponin, but without ST elevation on the ECG. It needs urgent antiplatelet and anticoagulant therapy, and most patients go on to coronary angiography.
Key symptoms
- Chest pressure or tightness at rest or lasting over 20 minutes
- Pain spreading to the arm, neck, jaw or back
- Shortness of breath, sweating, nausea
- Atypical symptoms such as fatigue or breathlessness in women, older adults and diabetics
What you find on exam
- Vital signs, oxygen saturation and pain level
- Signs of heart failure: crackles, S3, raised jugular venous pressure
- New murmur or low blood pressure
- Often a normal exam
Tests
- 12-lead ECG within 10 minutes: ST depression, T wave inversion or normal
- High-sensitivity troponin at arrival and repeated
- Risk score such as HEART or TIMI
- Electrolytes, kidney function, blood count, lipids; echo for wall motion
Treatment basics
- Aspirin 162 to 325 mg chewed, plus a second antiplatelet such as ticagrelor
- Anticoagulant such as heparin
- Nitroglycerin for pain if no low blood pressure; oxygen only if saturation is under 90 percent
- Beta blocker and high-intensity statin
- Coronary angiography: immediate if unstable, within 24 hours if high risk
Red flags
- Ongoing pain despite treatment
- Low blood pressure, heart failure or shock
- Ventricular arrhythmia
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Sources: NASEMSO National Model EMS Clinical Guidelines; NCCPA PANCE Content Blueprint; AAMC Core Entrustable Professional Activities (Core EPAs). Written by Making Synapses. Making Synapses is not affiliated with these organizations.