Masquerading details behind a murmur and chest pain
Alejandro Narvaez Orozco1,2
, Alberto Navarro Navajas1,2, Alejandra Ramirez Roldan1, Camilo Lopez Ocampo1, Juan Manuel Senior Sanchez1,2
1University of Antioquia, Hospital Universitario San Vicente Fundacion, Medellin, Colombia
2Division of Internal Medicine and Cardiology, Hospital Universitario San Vicente Fundacion, Medellin, Colombia
Keywords: Bundlebranch block, chest pain, heart murmurs, masquerading block, myocardial infarction
Abstract
Masquerading bundle branch block (MBBB) is a rare presentation of bifascicular blocks. It is the result of a right bundle branch block associated with an advanced left anterior fascicular block due to extensive damage to the conduction system. We present the case of a 75yearold male with late onset presentation anterior wall myocardial infarction (MI) with ongoing ischemia (which evolved into a ventricular septal defect [VSD]). Electrocardiographically, the MBBB is characterized by a prominent R in V1, left axis deviation and absence of small S waves in I and aVL. Its presence confers a poor prognosis and high risk of progressing to advanced atrioventricular block (AAVB). A mortality rate between 18% and 38.9% has been found and 41.4%–59% of the patients develop AAVB requiring pacemaker implantation. To our knowledge, this is the first reported MBBB case in the setting of an MI complicated with VSD, demonstrating its association with the presence of critical anteroseptal ischemia. The patient rejected any kind of intervention, palliative care was offered, and he died 2 months later.
How to cite this article: Orozco AN, Navajas AN, Roldan AR, Ocampo CL, Sanchez JM. Masquerading details behind a murmur and chest pain. Turk J Emerg Med 2025;25:59-62.