title: Atrioventricular block precipitated by isoproterenol.
abstract: An isoproterenol infusion was administered during an electrophysiologic study (EPS) in a patient with a history of near syncope, left bundle branch block, and no documented atrioventricular (AV) block. Isoproterenol precipitated classic 2:1 Infra-Hisian AV block most probably proximal to the site of recording a His-Purkinje potential consistent with right bundle branch activity. Paroxysmal AV block also occurred during isoproterenol washout at a different site located distal to the presumed right bundle branch potential. Isoproterenol may be valuable diagnostically in an occasional patient suspected of AV block in whom an EPS is unrevealing and a drug challenge is negative.
authors.affiliation: Florida Heart Rhythm Institute, Tampa, FL.
authors.forename: S Serge
authors.initials: SS
authors.lastname: Barold
authors.affiliation: Heart Center, Ghent University Hospital, Ghent, Belgium.
authors.forename: Hans E
authors.initials: HE
authors.lastname: De Wilde
authors.affiliation: Heart Center, Ghent University Hospital, Ghent, Belgium.
authors.forename: Liesbeth
authors.initials: L
authors.lastname: Timmers
authors.affiliation: Heart Center, Ghent University Hospital, Ghent, Belgium.
authors.forename: Frederic E
authors.initials: FE
authors.lastname: Van Heuverswyn
authors.affiliation: Heart Center, Ghent University Hospital, Ghent, Belgium.
authors.forename: Roland X
authors.initials: RX
authors.lastname: Stroobandt
mesh_terms: D000318:Adrenergic beta-Agonists / Q000009:adverse effects*; D054537:Atrioventricular Block / Q000139:chemically induced* / Q000150:complications / Q000503:physiopathology; D002036:Bundle of His / Q000503:physiopathology; D002037:Bundle-Branch Block / Q000150:complications / Q000503:physiopathology; D004562:Electrocardiography; D005260:Female; D006801:Humans; D007545:Isoproterenol / Q000009:adverse effects*; D008875:Middle Aged
chemical_list: D000318:Adrenergic beta-Agonists; D007545:Isoproterenol
keywords: atrioventricular block; electrophysiologic study; isoproterenol; paroxysmal atrioventricular block