Acute myocardial infarction with right bundle branch block at presentation: Prevalence and mortality.

<bold>Aims: </bold>Right Bundle Branch Block (RBBB) has been reported in 5-11% of the acute myocardial infarctions (AMI), and it could be the only electrocardiographic abnormality in this group of patients. We investigated the mortality in patients with AMI and the presence of RBBB.<bold>Materials and Methods: </bold>A retrospective cohort study was conducted between January 2011 to December 2017 at a university hospital in Bogotá, Colombia. Records were obtained from all patients who presented at the emergency department with AMI; patients with early transfer and incomplete follow-up were excluded.<bold>Results: </bold>1015 patients were included, the mean age was 66 years, 67% of the patients were men, and 38% had STEMI. RBBB was documented in 8% of patients and LBBB in 4% of patients. In-hospital mortality was higher in the group of patients with RBBB vs. patients without RBBB (8.64% vs. 3.74%, p = 0.034). The percentage of patients with Killip ≥II classification was higher in patients with new RBBB vs. patients with old or unknown duration RBBB (23% vs. 13%, p = 0.216).<bold>Conclusions: </bold>In patients with AMI, the presence of RBBB was associated with a statistically significant increase of in-hospital mortality. [ABSTRACT FROM AUTHOR]