Identifying acute MI in the setting of left bundle branch block (LBBB) is challenging because ST-segment elevation is often found at baseline. When faced with LBBB and ischemic symptoms, identifying which patients require urgent reperfusion therapy is critical. Sgarbossa et al. derived three criteria that can be used to help identify these patients, Smith et al. refined these criteria creating the Smith-modified Sgarbossa criteria. We present a case of LBBB meeting the Smith-modified Sgarbossa criteria, recognized by paramedics and used to activate the catheterization laboratory after normal business hours. The patient was found with 95% stenosis of the left anterior descending artery and received stenting.
Keywords: Sgarbossa; Smith-modified Sgarbossa; electrocardiography; left bundle-branch block; myocardial infarction.