Sgarbossa Criteria (predict AMI with LBBB) Reference

NEED greater than 2 points for AMI (90% specificity)

• Concordant ST segment elevation > 1mm in any lead (5 points)
• Concordant ST segment depression > 1mm in V1, V2, or V3 (3 points)
• Excessive discordant ST segment elevation > 5mm in any lead (2 points)

Modified Sgarbossa Rule (Reference) (Calculator)

Replace 3rd criteria with (in any lead):

• Ratio of STE (a positive number) to the preceding S-wave (a negative number)
• If that ratio ( -x / y ) is < -0.25 then the EKG suggests AMI
• Both ratio samples below are < -0.25 so both suggest AMI
  

Reference: http://hqmeded-ecg.blogspot.com/2012/09/modified-sgarbossa-rule-published_4.html
Reference: http://ems12lead.com/2010/12/excessive-discordance-as-a-marker-of-acute-stemi-in-lbbb/