Real-time validation of the Sgarbossa and modified Sgarbossa criteria in intermittent left bundle branch block

Abstract

The modified Sgarbossa criteria have been established to aid in the diagnosis of ST-elevation myocardial infarction in patients with left bundle branch block. Thus far, the sensitivities and specificities of the Sgarbossa signs have only been evaluated retrospectively in cohorts of patients with and without occlusive myocardial infarctions. These statistical analyses were based on correlating ST abnormalities with serum markers of myocardial injury and/or results of emergent cardiac catheterization. We present a patient with acute cardiovascular emergency where electrocardiograms revealed intermittent left bundle branch block. In serial ECGs, highly dynamic ST abnormalities on the narrow QRS beats were associated with similarly dynamic ST changes in the left bundle branch block beats. Our findings provided direct and real-time confirmation of the usefulness of the Sgarbossa and the modified Sgarbossa criteria in the diagnosis of acute ST elevation in patients with left bundle branch block.