title: Exercise-induced second-degree atrioventricular block.
abstract: In this report we describe the case of a 56-year-old woman with normal 1:1 AV conduction at rest who developed 2:1 AV block during treadmill exercise testing. Electrophysiological study documented 2:1 AV block proximal to the His bundle with reappearance of 1:1 AV conduction at a higher pacing atrial rate. A gap phenomenon involving a proximal and distal part of the AV node may be a likely explanation of paradoxical AV conduction in our case.
authors.forename: Loukas K
authors.initials: LK
authors.lastname: Pappas
authors.forename: Michalis
authors.initials: M
authors.lastname: Efremidis
authors.forename: Antonios
authors.initials: A
authors.lastname: Sideris
authors.forename: Konstantinos P
authors.initials: KP
authors.lastname: Letsas
authors.forename: Stavros P
authors.initials: SP
authors.lastname: Kounas
authors.forename: Fotios
authors.initials: F
authors.lastname: Kardaras
mesh_terms: D002036:Bundle of His; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac; D005080:Exercise Test / Q000009:adverse effects*; D005260:Female; D006327:Heart Block / Q000209:etiology*; D006801:Humans; D008875:Middle Aged