title: [Automatic modulation of refractoriness of His-Purkinje system during atrioventricular nodal reentrant tachycardia].
abstract: OBJECTIVE
  To illustrate the automatic modulation of refractoriness of His-Purkinje system during atrioventricular nodal reentrant tachycardia (AVNRT) and to discuss the possible mechanisms.
  
  
  METHODS
  Programmed electrical stimulations were performed in high right atrium (HRA) in 8 patients with AVNRT before ablation to induce tachycardia and electrocardiagraphic recordings were done synchronically when AVNRT appeared.
  
  
  RESULTS
  All the patients had 2:1 atrioventricular (A-V) conduction when AVNRT began, 2 of whom were blocked below His bundle, 5 above His bundle and 1 unclear. After a duration of 14.03 +/- 10.03 s of 2:1 A-V conduction, 1:1 A-V conduction with bundle banch block appeared, 3 of which were right bundle branch block (RBBB), 3 left bundle branch block (LBBB), and 2 with both. Bundle branch block disappeared after a duration of 6.87 +/- 11.26 s.
  
  
  CONCLUSIONS
  Effective refractory period (ERP) of His-Purkinje system at the beginning of AVNRT was modulated automatically within less than 30-60 s and thus facilitated nodal-ventricular conduction. The mechanism of this is electrical remodeling.
authors.affiliation: Department of Cardiology, First Affiliated Hospital, Nanjing Medical University, Nanjing 210029, China.
authors.forename: M
authors.initials: M
authors.lastname: Chen
authors.forename: K
authors.initials: K
authors.lastname: Cao
authors.forename: Q
authors.initials: Q
authors.lastname: Shan
authors.forename: J
authors.initials: J
authors.lastname: Zou
authors.forename: W
authors.initials: W
authors.lastname: Li
authors.forename: M
authors.initials: M
authors.lastname: Liao
authors.forename: Y
authors.initials: Y
authors.lastname: Huang
mesh_terms: D000328:Adult; D000368:Aged; D002036:Bundle of His / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011690:Purkinje Fibers / Q000503:physiopathology*; D012032:Refractory Period, Electrophysiological; D013611:Tachycardia, Atrioventricular Nodal Reentry / Q000503:physiopathology*