title: Transient disappearance of complete right bundle branch block during exercise in a patient with old inferior wall myocardial infarction.
abstract: To date, there has been no report of temporary disappearance of right bundle branch block (RBBB) during exercise. A patient with old infero-posterior myocardial infarction is described in whom complete RBBB disappeared transiently during treadmill exercise testing. No chest pain or significant ST-T changes occurred during and after the exercise periods. Any of the following mechanisms could have been involved: (1) the patient's complete RBBB might have been bradycardia-dependent, (2) an exercise-induced increase of sympathetic tone might have produced a temporary improvement of the conduction disturbances, or (3) the exercise might have elicited conduction disturbances in the main left bundle branch, which could have concealed a conduction delay in the main trunk of the right bundle branch.
authors.affiliation: Second Department of Internal Medicine, Kyorin University, School of Medicine, Tokyo, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Yotsukura
authors.forename: J
authors.initials: J
authors.lastname: Suzuki
authors.forename: M
authors.initials: M
authors.lastname: Tsuda
authors.forename: K
authors.initials: K
authors.lastname: Ishikawa
mesh_terms: D002037:Bundle-Branch Block / Q000175:diagnosis / Q000503:physiopathology*; D004562:Electrocardiography; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D006329:Heart Conduction System / Q000503:physiopathology*; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000503:physiopathology*