Sgarbossa's criteria

Background

• Assesses likelihood that pt w/ chest pain and baseline LBBB has myocardial damage
  • Criteria also applies to LBBB due to paced rhythm
• Low sensitivity, high specificity
  • Still consider PCI/t-PA for pts w/ LBBB and "good story" despite not meeting the criteria

Criteria

Original Criteria

Sgarbossa's Original Criteria

≥3 points = 98% probability of STEMI

• ST elevation ≥1 mm in a lead with upward QRS complex (concordant) - 5 points
• ST depression ≥1 mm in lead V1, V2, or V3 - 3 points
• ST elevation ≥5 mm in a lead with downward QRS complex (discordant) - 2 points

Smith's modification

Smith's Modified Sgarbossa 3rd Rule

• Changes the 3rd rule of original Sgarbossa's Criteria to be ST depression OR elevation discordant with the QRS complex and with a magnitude of at least 25% of the QRS
  • Increases Sn from 52% → 91% at the expense of reducing Sp from 98% → 90%

Example of all 3 criteria

See Also

• ST-Elevation Myocardial Infarction (STEMI)
• Original Study - Sgarbossa Criteria for MI in LBBB

External Links

1. http://lifeinthefastlane.com/ecg-library/basics/sgarbossa/

2. http://emcrit.org/podcasts/left-bundle-branch-block/

Source

• Sgarbossa, American Heart Journal 2006
• Sgarbossa, NEJM, February, 1996

Sgarbossa E. et al.. "Electrocardiographic diagnosis of evolving acute myocardial infarction in the presence of left bundle-branch block. GUSTO-1 (Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries) Investigators". NEJM. 1996. 334(8):481-7

Smith, S. et al. Diagnosis of ST-Elevation Myocardial Infarction in the Presence of Left Bundle Branch Block With the ST-Elevation to S-Wave Ratio in a Modified Sgarbossa Rule. 60(6). 766-776