Managing chest pain in patients with concomitant left bundle-branch block.

Diagnosis and timely management of acute myocardial infarction (MI) relies heavily on the ST-segment elevation sum. Presence of concomitant left bundle-branch block (LBBB) in patients presenting with possible acute MI presents a diagnostic dilemma. The LBBB pattern distorts ST-segment changes, delaying or preventing accurate diagnosis. This article reviews the Sgarbossa criteria and ST/S ratio and presents a treatment algorithm that may help improve patient care and reduce morbidity and mortality.