Masquerading bundle branch block obscuring the diagnosis of Brugada syndrome: an electrocardiographic and vectorcardiographic study

Key Clinical Message We describe the induction of a masquerading bundle branch block in two patients with Brugada syndrome following the administration of Ajmaline. The development of this conduction disturbance prevented the correct electrocardiographic diagnosis. However, the simultaneously obtained vectocardiogram identified both the Brugada pattern and the masquerading bundle branch block. We describe the induction of a masquerading bundle branch block in two patients with Brugada syndrome following the administration of Ajmaline. The development of this conduction disturbance prevented the correct electrocardiographic diagnosis. However, the simultaneously obtained vectocardiogram identified both the Brugada pattern and the masquerading bundle branch block.