ST segment depression

• DDx: Post. STEMI, Subendocardial Infarct, Ischemia, Reciporical Changes, Strain c LVH, Dig effect
• Contour: Most-->Least concerning for ischemia: Planar/Flat (90%) --> Concave up (33%) --> Downsloping with Asymmetric inverted T-wave (not ischemic/strain pattern)
• Assume posterior STEMI or reciprocal changes to STEMI until proven otherwise
• Indicators of ischemia:
  • >0.5mm depression from baseline (especially >1mm) in two or more contiguous leads
  • Transient depression
  • Morphology that is flat or downsloping
• Strain: 
  
  • tall R wave
  • only in lateral leads (not anterior)
  • "checkbox" or asymmetric TWI
  • down sloping pattern

DDX

1. Posterior MI
2. RV strain
3. NSTEMI
4. Reciprocal changes
5. Electrolyte Disorders (e.g. hypokalemia)
6. LVH with strain pattern (repolarization abnormality)
7. Digoxin effect (not indicative of toxicity)

See Also

• ECG (Main)

Source

ST Elevation Lecture, Dr. Niemann, Harbor-UCLA