← Diagnosis and Management Guides
ST-Elevation Myocardial Infarction
Key considerations: STEMI, Aortic dissection with coronary involvement, Myocarditis
Cannot miss
- STEMI
- Aortic dissection with coronary involvement
- Myocarditis
- Takotsubo cardiomyopathy
Likely diagnoses
- Acute STEMI
- Pericarditis (diffuse ST elevation)
- Early repolarization
- LV aneurysm
Red flags
- ST elevation in 2+ contiguous leads
- New LBBB with clinical suspicion
- Cardiogenic shock
- Mechanical complications (VSD, papillary muscle rupture)
Workup
- history: Chest pain onset, duration, associated symptoms, cardiac risk factors; exam: Heart sounds (new murmur = mechanical complication), signs of CHF, bilateral BPs (dissection); labs: Troponin (do NOT delay reperfusion for troponin result); CBC, BMP, coags, type and screen; imaging: ECG within 10 minutes of arrival; Echo for wall motion, complications; bedside: 12-lead ECG, right-sided ECG if inferior STEMI
Management
- immediate: Activate cath lab — door-to-balloon <90 minutes; Aspirin 324mg chewed; P2Y12 inhibitor (ticagrelor 180mg or clopidogrel 600mg); Heparin bolus per PCI protocol; general: If PCI not available within 120 min: fibrinolytic therapy (tPA); Beta-blocker within 24hr if no contraindications; High-intensity statin; ACEi within 24hr if anterior STEMI or EF <40%; Dual antiplatelet therapy x12 months
Disposition
- admit: All STEMI patients — CCU or monitored bed after PCI; discharge: After stabilization, typically 2-3 days post-PCI if uncomplicated; consults: Interventional cardiology emergently
Clinical pearls
- Every 30-minute delay in reperfusion increases mortality — time is myocardium
- Right-sided ECG (V4R) in inferior STEMI: RV involvement means avoid nitroglycerin and volume depletion
- Posterior STEMI: ST depression V1-V3 — get posterior leads (V7-V9) or flip the ECG
Source and review
- ACC/AHA STEMI Guidelines 2013 (focused update 2017). Last reviewed: 2024-11-01