title: Two distinct electrocardiographic forms of idiopathic ventricular arrhythmia originating in the vicinity of the His bundle.
abstract: OBJECTIVE
  The objective is to assess electrocardiographic characteristics predicting the precise location of ventricular arrhythmia (VA) origin within the right ventricle (RV) close to the His bundle (HB) region.
  
  
  RESULTS
  Twenty-five patients (14 men, age 65 ± 14 years) underwent successful catheter ablation of para-Hisian VA. Ventricular arrhythmias were considered to arise in the vicinity of the HB region based on the criteria that mapping exhibited the earliest RV activation before QRS onset in the HB region. Surface 12-lead electrocardiogram during the para-Hisian VAs was analysed. Of the 25 patients, 8 originated from the RV antero-septum just above the HB region, and 17 arose from the RV mid-septum just below the HB region. There was no significant difference in precedence of the local ventricular electrogram of the HB region from the onset of surface QRS during VAs. Surface electrocardiographic findings were characterized according to R-wave amplitude in lead I (0.43 ± 0.18 vs. 0.67 ± 0.19 mV, P = 0.005), mean R-wave amplitude in inferior leads (1.12 ± 0.32 vs. 0.71 ± 0.24 mV, P = 0.002), R-wave amplitude ratio of leads III/II (0.77 ± 0.10 vs. 0.50 ± 0.23, P = 0.005), incidence of S-wave in lead III [1/8 (13%) vs. 16/17 (94%), P < 0.001], and QS morphology in lead V1 [3/8 (38%) vs. 17/17 (100%), P = 0.001].
  
  
  CONCLUSIONS
  Despite their adjacent locations, para-Hisian VAs could be classified into two subgroups with distinctive electrocardiographic characteristics according to origin either above or below the HB region. The present findings can be helpful for planning catheter ablation of para-Hisian VAs, and can reduce the risk of inadvertent atrioventricular block.
authors.affiliation: Department of Cardiology, Cardiovascular Center, Tsuchiura Kyodo Hospital, 11-7 Manabe-Shinmachi, Tsuchiura, Japan. yk.komat@gmail.com
authors.forename: Yuki
authors.initials: Y
authors.lastname: Komatsu
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Taniguchi
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Miyazaki
authors.forename: Shigeki
authors.initials: S
authors.lastname: Kusa
authors.forename: Kei
authors.initials: K
authors.lastname: Takayama
authors.forename: Ken
authors.initials: K
authors.lastname: Kakita
authors.forename: Kenji
authors.initials: K
authors.lastname: Koura
authors.forename: Takashi
authors.initials: T
authors.lastname: Uchiyama
authors.forename: Tsunekazu
authors.initials: T
authors.lastname: Kakuta
authors.forename: Hideomi
authors.initials: H
authors.lastname: Fujiwara
authors.forename: Yoshito
authors.initials: Y
authors.lastname: Iesaka
mesh_terms: D002036:Bundle of His / Q000503:physiopathology* / Q000601:surgery*; D004562:Electrocardiography / Q000379:methods*; D022062:Electrophysiologic Techniques, Cardiac / Q000379:methods*; D005260:Female; D006352:Heart Ventricles / Q000503:physiopathology* / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016896:Treatment Outcome; D014693:Ventricular Fibrillation / Q000503:physiopathology* / Q000601:surgery*