title: Ventriculoatrial Intervals ≤70 ms in Orthodromic Atrioventricular Reciprocating Tachycardia.
abstract: BACKGROUND
  Although a ventriculoatrial interval (VAI) of ≤70 ms is used to distinguish atrioventricular nodal reentrant tachycardia from orthodromic atrioventricular reciprocating tachycardia (AVRT), a VAI of ≤70 ms is sometimes observed in cases of AVRT. The study aimed to evaluate the short VAI that is seen in AVRT and to understand its underlying mechanism.
  
  
  METHODS
  Electrophysiologic studies of 46 consecutive patients with AVRT involving an accessory pathway (AP) were examined retrospectively.
  
  
  RESULTS
  AP was right sided in seven patients and left sided in 39. A VAI (interval from QRS onset to the earliest intracardiac atrial electrogram recorded by any mapping catheter during AVRT) ≤70 ms during AVRT (short VAI) was observed in eight patients: six with a left lateral AP and two with a left posteroseptal AP. During AVRT involving a left-sided AP, the QRS-V interval (from the earliest QRS onset to the local ventricular electrogram at a site which showed earliest atrial electrogram recorded from the coronary sinus catheter) was significantly shorter (37 ± 7 ms vs 54 ± 13 ms, P = 0.001) and supernormal conduction (QRS duration or the QRS-V interval shortening by ≥10 ms during AVRT) was more frequently seen (63% vs 6%, P = 0.02) in the short VAI group than in the normal VAI group. Furthermore, these parameters were shown to be determinants for short VAI.
  
  
  CONCLUSIONS
  A short VAI is sometimes observed during AVRT involving a left-sided AP. The short VAI may be caused by rapid propagation or supernormal conduction between the proximal Purkinje-muscle junction and basal left ventricular myocardium.
authors.affiliation: Division of Cardiology, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan. cocakochan@gmail.com.
authors.forename: Koichi
authors.initials: K
authors.lastname: Nagashima
authors.affiliation: Division of Cardiology, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan.
authors.forename: Ichiro
authors.initials: I
authors.lastname: Watanabe
authors.affiliation: Division of Cardiology, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Okumura
authors.affiliation: Department of Medicine and Biological Science, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Kaneko
authors.affiliation: Division of Cardiology, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan.
authors.forename: Kazumasa
authors.initials: K
authors.lastname: Sonoda
authors.affiliation: Division of Cardiology, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan.
authors.forename: Rikitake
authors.initials: R
authors.lastname: Kogawa
authors.affiliation: Division of Cardiology, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan.
authors.forename: Naoko
authors.initials: N
authors.lastname: Sasaki
authors.affiliation: Division of Cardiology, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan.
authors.forename: Kazuki
authors.initials: K
authors.lastname: Iso
authors.affiliation: Division of Cardiology, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Takahashi
authors.affiliation: Division of Cardiology, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan.
authors.forename: Sayaka
authors.initials: S
authors.lastname: Kurokawa
authors.affiliation: Division of Cardiology, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan.
authors.forename: Toshiko
authors.initials: T
authors.lastname: Nakai
authors.affiliation: Division of Cardiology, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan.
authors.forename: Kimie
authors.initials: K
authors.lastname: Ohkubo
authors.affiliation: Division of Cardiology, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Hirayama
mesh_terms: D058606:Accessory Atrioventricular Bundle / Q000503:physiopathology; D001283:Atrioventricular Node / Q000503:physiopathology; D003937:Diagnosis, Differential; D004594:Electrophysiology; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D013611:Tachycardia, Atrioventricular Nodal Reentry / Q000175:diagnosis; D054139:Tachycardia, Reciprocating / Q000175:diagnosis / Q000503:physiopathology*
keywords: accessory pathway; orthodromic atrioventricular reciprocating tachycardia; supernormal conduction; supraventricular tachycardia; ventriculoatrial interval