Sgarbossa Criteria — modified

17 Dec


–Sgarbossa criteria help look for STEMIs in people with LBBB (left bundle branch block)


5 pts – concordant (same direction as QRS complex) ST elevation >=1mm any lead
3 pts – ST depression >=1mm in anterior leads (V1, V2, V3)
2 pts – discordant (opposite direction of QRS) ST elevation >=5mm any lead

–add up the points, score >=3 is 90+ percent specific for an MI

Smith et al study:

admission ECGs for all patients with an acutely occluded coronary artery and left bundle branch block

R or S wave, whichever was most prominent, and ST segments, relative to the PR segment, were msmith-sgareasured to the nearest 0.5 mm.

ST/S ratio was calculated for each lead that has discordant ST deviation of greater than or equal to 1 mm

cutoff for proposed rule was ST/S ratio <=  -0.25  (e.g. more discordant)

The study and control groups included 33 and 129 ECGs, respectively.



  • (3rd sgarbossa criteria) discordant ST-segment elevation of 5 mm was present in at least one lead in 30% of ECGs in patients AMI vs 9% of the control group
  • (proposed criteria) ST/S ratio less than (i.e. more negative than; more relative discordance than) -0.25 was present in 58% versus 8%.
  • Sensitivity of the revised rule (proposed ST/S ratio rule replaces 5mm ST elevation rule): 91% versus 52%.
  • Specificity of the revised rule was lower than that of the weighted rule (P=.002) and similar to that of the unweighted rule (P=1.0): 90%  versus 98% versus 90%.
  • Positive likelihood ratio for the revised rule 9.0
  • negative liklihood ratio for the revised rule 0.1



“Replacement of the absolute ST-elevation measurement of greater than or equal to 5 mm in the third component of the Sgarbossa rule with an ST/S ratio less than -0.25 greatly improves diagnostic utility of the rule for STEMI.”



the ST/S ratio rule seems more sensitive, similar specificity of old rule.


–you’re handed an EKG, there’s a LBBB

–look for >=1mm concordant ST elevation
–look for ST depression in anterior leads

–look for discordant ST deviation; if ST segment change is > 1/4th the amplitude of the R or S-wave, be curious


–if you see these things, worry about an MI


Reference(s): old post; article; picture is from the article


2 Responses to “Sgarbossa Criteria — modified”


  1. Sgarbossa and pacemakers « DAILYEM - December 18, 2012

    […] quick refresher’s HERE and HERE […]

  2. Sgarbossa revisited – MI in LBBB | DAILYEM - September 25, 2013


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