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Sgarbossa's Criteria for MI in Left Bundle Branch Block
Sgarbossa's Criteria for MI in Left Bundle Branch Block
Concordant ST elevation ≥1 mm in a lead with a positive QRS
Concordant ST depression ≥1 mm in lead V1, V2, or V3
Discordant ST elevation ≥5 mm in a lead with a negative QRS
Result0 points
Does not meet the diagnostic threshold; does not exclude MI.
When to use
- Evaluating for acute MI on an ECG showing LBBB or ventricular paced rhythm, where standard ST-elevation criteria cannot be applied.
Formula
Concordant ST elevation ≥1mm = 5 points; concordant ST depression ≥1mm in V1-V3 = 3 points; discordant ST elevation ≥5mm = 2 points. Score ≥3 is diagnostic.
Pearls and pitfalls
- A modified rule (excessive discordance as a ratio ≥0.25 rather than an absolute 5mm) improves sensitivity and is commonly used alongside the original criteria.