title: Fast-slow and slow-slow form of atrioventricular nodal reentrant tachycardia sustained by the same reentrant circuit: a case report.
abstract: It has been suggested that a reentrant circuit confined to the posterior extensions of the atrioventricular node underlies both fast-slow and slow-slow types of atrioventricular nodal reentrant tachycardia (AVNRT). According to this hypothesis the fast-slow reentrant circuit would be formed by two slow pathways, located in the rightward and leftward posterior extension of the atrioventricular node. Thus, the fast pathway would act as a bystander with respect to the reentrant circuit. We describe the case of a 40-year-old woman with several episodes of palpitations unresponsive to antiarrhythmic drugs. The ECG during symptoms showed a narrow QRS tachycardia with a long ventriculo-atrial interval and a negative P wave in the inferior leads. Electrophysiological study showed the inducibility of a slow-slow AVNRT which rapidly shifted to a fast-slow AVNRT without any change in the duration of the tachycardia cycle. Our observation is in agreement with the hypothesis that the fast-slow reentrant circuit consists of two slow pathways with the fast pathway acting as a bystander.
authors.affiliation: Department of Cardiology, IRCCS Policlinico San Matteo, Pavia, Italy. elettrofisiologia@smatteo.pv.it
authors.forename: Francesco
authors.initials: F
authors.lastname: Cantù
authors.forename: Paolo
authors.initials: P
authors.lastname: De Filippo
authors.forename: Roberto
authors.initials: R
authors.lastname: Rordorf
authors.forename: Gaetano M
authors.initials: GM
authors.lastname: De Ferrari
authors.forename: Folco
authors.initials: F
authors.lastname: Frattini
authors.forename: Barbara
authors.initials: B
authors.lastname: Petracci
authors.forename: Giovanni
authors.initials: G
authors.lastname: Russo
authors.forename: Marina
authors.initials: M
authors.lastname: Cerrone
authors.forename: Maurizio
authors.initials: M
authors.lastname: Landolina
mesh_terms: D000328:Adult; D001283:Atrioventricular Node / Q000503:physiopathology*; D002036:Bundle of His / Q000503:physiopathology / Q000601:surgery; D017115:Catheter Ablation; D004562:Electrocardiography; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D013611:Tachycardia, Atrioventricular Nodal Reentry / Q000503:physiopathology* / Q000601:surgery