Sgarbossa Criteria: Used to identify acute myocardial infarction (AMI) in the presence of Left Bundle Branch Block (LBBB) or ventricular paced rhythm. A score ≥ 3 is highly specific for AMI.
Criteria Assessment
Guidelines & Evidence
Clinical Details
Section 1
When to Use
When to Use
Evaluation of suspected Acute Myocardial Infarction (AMI) in patients with a Left Bundle Branch Block (LBBB).
To differentiate baseline LBBB ST-changes from acute ischemia.
In patients with ventricularly paced rhythms (pacemaker).
Section 2
Formula & Logic
The Rule of Discordance
In normal LBBB, the ST segment and T wave should be "discordant" (opposite) to the main QRS deflection. Sgarbossa criteria identify AMI by looking for "concordance" (ST deviation in the same direction as the QRS) or "excessive discordance."
Scoring Criteria
Concordant ST elevation ≥ 1 mm in any lead
5 pts
Concordant ST depression ≥ 1 mm in lead V1, V2, or V3
3 pts
Discordant ST elevation ≥ 5 mm in leads with negative QRS
2 pts
Interpretation
A score ≥ 3 has a specificity of ~98% for AMI, though sensitivity is low (~20-30%).
Section 3
Pearls/Pitfalls
LBBB = STEMI?
Recent ESC and AHA guidelines no longer consider "new LBBB" alone as a STEMI equivalent unless symptoms are refractory. Sgarbossa criteria help identify the subset of LBBB patients who truly have an occluded artery and need the cath lab.
Section 4
Next Steps
Complementary Calculators
Modified Sgarbossa Criteria
HEART Score (Chest Pain)
GRACE ACS Risk Score
TIMI Risk Score (STEMI)
Killip Classification
Section 5
Evidence Appraisal
Original Study
Electrocardiographic diagnosis of evolving acute myocardial infarction in the presence of left bundle-branch block.
Sgarbossa EB et al. • N Engl J Med.. 1996;334(8):481–7. Derived from the GUSTO-1 trial.
