Sgarbossa NEJM 334:8 481-7 Feb 1996
Rule of appropriate discordance: In LBBB with out STEMI the major terminal portion of QRS and initial upsloping portion of the ST/T segment should lie on opposite sides of isoelectric baseline = "discordance"
Sgarbossa Criteria for MI in presence of LBBB
- ST-segment elevation ≥1 mm concordant with (in the same direction as) a predominantly positive QRS complex in at least one lead. (5 pt.)
- ST ↓ ≥ 1mm in leads V1, V2 or V3 (3 pt)
- ST ↑ ≥ 5mm discordant (in the opposite direction from) a predominantly negative QRS complex. (1 pt.) This 3rd criteria has not been shown to be useful.
