title: The electrophysiologic characteristics in patients with only ventricular-pacing inducible slow-fast form atrioventricular nodal reentrant tachycardia.
abstract: BACKGROUND
  Atrioventricular nodal reentrant tachycardia (AVNRT) can be usually induced by atrial pacing or extrastimulation. However, it is less commonly induced only by ventricular pacing or extrastimulation.
  
  
  OBJECTIVE
  The purpose of this retrospective study was to investigate the electrophysiologic characteristics in patients with slow-fast form AVNRT that could be induced only by ventricular pacing or extrastimulation.
  
  
  METHODS
  The total population was 1497 patients associated with AVNRT. There were 1373 (91.7%) patients who had slow-fast form AVNRT included in our study. Group 1 (n = 45) could be induced only by ventricular pacing or extrastimulation, and Group 2 (n = 1328) could be induced by only atrial stimulation or both atrial and ventricular stimulation. The electrophysiologic characteristics of the group 1 and group 2 patients were compared.
  
  
  RESULTS
  Group 1 patients had a significantly lower incidence of both antegrade and retrograde dual AV nodal pathways. The pacing cycle length (CL) of the antegrade 1:1 fast pathway (FP) and antegrade ERP of the FP were both significantly shorter in Group 1 patients. Mean antegrade FRP of the fast and slow pathways were significantly shorter in Group 1 patients. The differences of pacing CL of 1:1 antegrade conduction, antegrade ERP and FRP were much longer in Group 2 patients.
  
  
  CONCLUSIONS
  This study demonstrated the patients with slow-fast form AVNRT that could be induced only by ventricular stimulation had a lower incidence of dual AV nodal pathways and the different electrophysiologic characteristics (shorter pacing CL of the antegrade 1:1 FP, antegrade ERP of the FP and the differences of pacing CL of 1:1 antegrade conduction, antegrade ERP and FRP) from the other patients. The specific electrophysiologic characteristics in such patients could be the reason that could be induced only by ventricular stimulation.
authors.affiliation: Department of Pediatrics, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Pi-Chang
authors.initials: PC
authors.lastname: Lee
authors.forename: Ching-Tai
authors.initials: CT
authors.lastname: Tai
authors.forename: Betau
authors.initials: B
authors.lastname: Hwang
authors.forename: Ming-Hsiung
authors.initials: MH
authors.lastname: Hsieh
authors.forename: Chin-Feng
authors.initials: CF
authors.lastname: Tsai
authors.forename: Chern-En
authors.initials: CE
authors.lastname: Chiang
authors.forename: Wen-Chung
authors.initials: WC
authors.lastname: Yu
authors.forename: Hsuan-Ming
authors.initials: HM
authors.lastname: Taso
authors.forename: Kun-Tai
authors.initials: KT
authors.lastname: Lee
authors.forename: Yoga
authors.initials: Y
authors.lastname: Yuniadi
authors.forename: Wanwarang
authors.initials: W
authors.lastname: Wongchaoen
authors.forename: Shih-Ann
authors.initials: SA
authors.lastname: Chen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002304:Cardiac Pacing, Artificial; D016009:Chi-Square Distribution; D002648:Child; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006352:Heart Ventricles / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013611:Tachycardia, Atrioventricular Nodal Reentry / Q000503:physiopathology*