title: Spontaneous paroxysmal atrioventricular block in patients with positive tilt tests and negative electrophysiologic studies.
abstract: A subgroup of patients with neurocardiogenic syncope and negative electrophysiologic studies and adenosine tests (in 5 of 6 cases), who developed symptomatic paroxysmal atrioventricular block in the natural, ambulatory state, had positive tilt tests without advanced block. Lack of concordance between electrocardiographic changes may have reflected differential effects of the autonomic nervous system in the sinus and atrioventricular nodes, occurring in diverse circumstances and less likely because of the protocol used for tilt testing.
authors.affiliation: Universidad Central de Venezuela, Caracas.
authors.forename: I J
authors.initials: IJ
authors.lastname: Mendoza
authors.forename: A
authors.initials: A
authors.lastname: Castellanos
authors.forename: G
authors.initials: G
authors.lastname: Lopera
authors.forename: F
authors.initials: F
authors.lastname: Moleiro
authors.forename: R D
authors.initials: RD
authors.lastname: Mitrani
authors.forename: R J
authors.initials: RJ
authors.lastname: Myerburg
mesh_terms: D000328:Adult; D001283:Atrioventricular Node / Q000503:physiopathology; D003937:Diagnosis, Differential; D015716:Electrocardiography, Ambulatory; D005260:Female; D006327:Heart Block / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D013575:Syncope / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D013614:Tachycardia, Paroxysmal / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology; D018667:Tilt-Table Test