The electrophysiological change of fast pathway property after slow pathway ablation in children with atrio-ventricular nodal reentrant tachycardia

  • Masaharu Matsumura, Japan
  • Naokata Sumitomo, Department of Pediatrics and Child health, Nihon University School of Medicine, Tokyo, Japan
  • Hiroya Ushinohama, Department of Cardiovascular system, Fukuoka children’s Hospital & Medical Center for Infectious Disease, Fukuoka, Japan
  • Kazuo Taniguchi, Department of Pediatrics and Child health, Nihon University School of Medicine, Tokyo, Japan
  • Junji Fukuhara, Department of Pediatrics and Child health, Nihon University School of Medicine, Tokyo, Japan
  • Hiroshi Kanamaru, Department of Pediatrics and Child health, Nihon University School of Medicine, Tokyo, Japan
  • Mamoru Ayusawa, Department of Pediatrics and Child health, Nihon University School of Medicine, Tokyo, Japan
  • Hideo Mugishima, Department of Pediatrics and Child health, Nihon University School of Medicine, Tokyo, Japan

    • Background: Electrophysiological property of the fast pathway (FP) may change after slow pathway (SP) ablation in patients with atrio-ventricular nodal reentrant tachycardia (AVNRT).
    Methods: A consecutive 42patients (mean±SD age = 13.2 ± 5.7 years; M/F= 23/19 ) with AVNRT, who performed successful SP ablation were included in this study fromAugust 1998 to December 2008. The AH interval, HV interval, the effective refractory period (ERP), functional refractory period (FRP), and Wenckebach rate of FP were compared before and after ablation of SP.
    Results: HV interval was not changed before (50 ± 10 ms) and after (52 ± 10 ms) ablation. However, mean ERP of the FP was decreased from 346.8 ± 86.5 ms to 253.5 ± 68.9 ms (P < 0.001); mean FRP of the FP was decreased from 422.2 ± 87.1 ms to 371.4 ± 72.0 ms (P < 0.001); mean Wenckebach rate was increased from 167.7 ± 35.2 /min to 188.2 ± 29.3 /min (P = 0.005); and AH interval was decreased from 98 ± 24 ms to 91 ± 28 ms (P = 0.026).
    Conclusions: The values of ERP, FRP of FP and AH interval were decreased, and Wenckebach rate of atrio-ventricular node was increased in patients of AVNRT after slow pathway ablation. These finding may indicate not only functional interaction of FP and SP but autonomic nerves interaction is existed in patients with AVNRT.