Sgarbossa Criteria

Benoit Phelan PGY2 FM/EM

ECG diagnosis of AMI in the presence of LBBB continues to be a challenge. The 2004 ACCF/AHA STEMI guidelines recommended treating new or presumably new LBBB in symptomatic patients as a STEMI equivalent. In the newest 2013 STEMI guidelines this recommendation has been removed and no alternative diagnostic tool was proposed. The former guideline led to an increase in inappropriate catheterizations and use of fibrinolysis and the later to missed situations that could have benefited from reperfusion.

The Sgarbossa criteria were developed in 1996 and are the most validated tool for the diagnosis of AMI in the presence of LBBB. It has shown to be a highly specific tool (>95%) but has very limited sensitivity (20%). The addition of an additional criterion, the ST/S ratio, has been proposed to help increase sensitivity without significantly decreasing specificity, although it has not been fully adopted.

Can you list the three independent predictors in the Sgarbossa Criteria?

Score ≥3 is highly specific for AMI

… scroll down for answers…

Answers…

1 – ST-segment elevation ≥1 mm concordant with the QRS complex in any lead (5 points)

2 – ST-segment elevation ≥5 mm discordant with the QRS complex in any lead (2 points)

3 – ST-segment depression ≥1 mm in lead V1, V2, or V3 (3 points)

References 

Cai, Q., Mehta, N., Sgarbossa, E. B., Pinski, S. L., Wagner, G. S., Califf, R. M., & Barbagelata, A. (2013). The left bundle-branch block puzzle in the 2013 ST-elevation myocardial infarction guideline: from falsely declaring emergency to denying reperfusion in a high-risk population. Are the Sgarbossa Criteria ready for prime time? American Heart Journal, 166(3), 409–13. doi:10.1016/j.ahj.2013.03.032

Jain, S., Ting, H. T., Bell, M., Bjerke, C. M., Lennon, R. J., Gersh, B. J., … Prasad, A. (2011). Utility of left bundle branch block as a diagnostic criterion for acute myocardial infarction. The American Journal of Cardiology, 107(8), 1111–6. doi:10.1016/j.amjcard.2010.12.007

O’Gara, P. T., Kushner, F. G., Ascheim, D. D., Casey, D. E., Chung, M. K., de Lemos, J. a, … Yancy, C. W. (2013). 2013 ACCF/AHA guideline for the management of ST-elevation myocardial infarction: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. Journal of the American College of Cardiology, 61(4), e78–140. doi:10.1016/j.jacc.2012.11.019