title: The Relationship between the Profiles of SVC and Sustainability of SVC Fibrillation Induced by Provocative Electrical Stimulation.
abstract: BACKGROUND
  Superior vena cava (SVC) can be a focus of atrial fibrillation (AF). However, distinctive features that identify SVC arrhythmogenicity remain unclear. Sustainability of fibrillation within the SVC might help with identifying SVC arrhythmogenicity. The purpose of this study was to investigate the relationship between the anatomical and electrical profiles of SVC and sustainability of SVC fibrillation induced by proactive electrical stimulation.
  
  
  METHODS
  Consecutive 36 patients with paroxysmal or persistent AF who underwent repetitive pulmonary vein isolation (PVI) session were included in the study. After successful PVI, periodic rapid electrical stimuli were delivered to the SVC to induce SVC fibrillation. SVC fibrillation was defined as follows: (1) the local fibrillatory electrical activity persisted longer than 3 seconds, (2) the local fibrillatory activity penetrated through the atrium and maintained AF, and (3) the frequency of local activity was higher than that of any other atrial components such as coronary sinus and right atrial appendage.
  
  
  RESULTS
  SVC fibrillation was induced in seven patients. The group with SVC fibrillation had significantly longer SVC sleeve and longer left atrial diameter compared with the group without SVC fibrillation. All patients with SVC fibrillation were free from AF recurrence after SVC isolation.
  
  
  CONCLUSIONS
  The SVC sleeve longer than 30 mm had sustainability of SVC fibrillation induced by electrical stimulation. This finding advocates that arrhythmogenic substrate may exist in the SVC with long myocardial sleeve.
authors.affiliation: Heart Rhythm Center, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Tomofumi
authors.initials: T
authors.lastname: Nakamura
authors.affiliation: Heart Rhythm Center, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Hachiya
authors.affiliation: Heart Rhythm Center, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Atsuhiko
authors.initials: A
authors.lastname: Yagishita
authors.affiliation: Heart Rhythm Center, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Yasuaki
authors.initials: Y
authors.lastname: Tanaka
authors.affiliation: Heart Rhythm Center, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Higuchi
authors.affiliation: Heart Rhythm Center, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Mihoko
authors.initials: M
authors.lastname: Kawabata
authors.affiliation: Heart Rhythm Center, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Sasano
authors.affiliation: Heart Rhythm Center, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Kenzo
authors.initials: K
authors.lastname: Hirao
mesh_terms: D000328:Adult; D001281:Atrial Fibrillation / Q000175:diagnosis* / Q000503:physiopathology*; D018780:Body Surface Potential Mapping / Q000379:methods*; D004558:Electric Stimulation / Q000379:methods*; D022062:Electrophysiologic Techniques, Cardiac / Q000379:methods; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014683:Vena Cava, Superior / Q000503:physiopathology*
keywords: arrhythmogenicity; atrial fibrillation; nonpulmonary vein focus; pacing; superior vena cava