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Updated: Oct 10, 2026

Benefits of Cardiac Resynchronization Therapy in an Asynchronous Heart Failure Model Induced by Left Bundle Branch Ablation and Rapid Pacing
Published on: December 11, 2017
Right bundle branch block-induced Q waves simulating anterior myocardial infarction extension
J Ortega-Carnicer1, M L Gómez-Grande, A Ambrós
1Coronary Care Unit, Hospital Alarcos, Ciudad Real, Spain.
Abstract:
A concept generally accepted in clinical electrocardiography is the assumption that a right bundle branch block (RBBB) does not alter significantly the initial portion of the QRS complex and because the left bundle branch is intact, the septum is activated normally in a left-to-right direction. We report a woman with an acute anterior myocardial infarction (MI) in which a small R wave was present in leads V1 and V4, but with the development of RBBB associated with PR-interval prolongation, these R waves were replaced by Q waves. Subsequently, the electrocardiographic features of anterior MI disappeared concomitantly with the loss of RBBB. The clinical and electrophysiologic implications of these findings are discussed.
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