Sgarbossa Criteria

Question 1

What is meant by the term “discordance?”

Answer 1

QRS complex is in the opposite direction of T-wave.

Question 2

In LBBB, the QRS complex is deeply negative in what leads?

Answer 2

V1-V3.

Question 3

Because of deeply negative QRS waves in leads V1-V3 in the presence of LBBB, what “rule” is used to determine presence of ischemia?

Answer 3

Proportion rule:

• Excessive discordant STE, as defined by ≥ 25% of the depth of the preceding S-wave.
• STE/QRS depth > 0.25 = No STEMI