Curated insights • How it Works • Practical Pearls • Evidence Base
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."
| Concordant ST elevation ≥ 1 mm in any lead |
| Concordant ST depression ≥ 1 mm in lead V1, V2, or V3 |
| Discordant ST elevation ≥ 5 mm in leads with negative QRS |
A score ≥ 3 has a specificity of ~98% for AMI, though sensitivity is low (~20-30%).
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.
Electrocardiographic diagnosis of evolving acute myocardial infarction in the presence of left bundle-branch block.
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.
Curated insights • How it Works • Practical Pearls • Evidence Base
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."
| Concordant ST elevation ≥ 1 mm in any lead |
| Concordant ST depression ≥ 1 mm in lead V1, V2, or V3 |
| Discordant ST elevation ≥ 5 mm in leads with negative QRS |
A score ≥ 3 has a specificity of ~98% for AMI, though sensitivity is low (~20-30%).
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.
Electrocardiographic diagnosis of evolving acute myocardial infarction in the presence of left bundle-branch block.