title: Confined thoracic vein fibrillation: prevalence and electrophysiological properties.
abstract: BACKGROUND
  Confined thoracic vein fibrillation (cTVT) is a finding that suggests that thoracic vein acts as a rapid driver to maintain atrial fibrillation (AF). However, little is known about the cTVT.
  
  
  RESULTS
  Among consecutive 655 patients (age 62 ± 0 years, 492 men, 421 paroxysmal) who underwent circumferential pulmonary vein (PV) antrum isolation for AF, cTVT was identified in 28 (4.3%) patients. The prevalence was significantly higher in patients with paroxysmal AF than in those with nonparoxysmal AF (5.9% vs 1.3%, P = .002). The cTVT was observed in left PVs in 15 (53.6%), right PVs in 11 (39.3%), and superior vena cava in 2 (7.1%) patients. The median cycle length of cTVT was 150 (110-170) ms. The cTVT was recognized when sinus rhythm was restored from AF during vein isolation in 14 patients. Dissociated activity was seen after the termination of cTVT in 23 (82.1%) patients, and cTVT reinitiated spontaneously after the dissociated activity. In 2 patients, AF was not terminated by multiple cardioversions before the isolation, even with a maximal energy delivery. At a median follow-up of 12.0 (7.5-20.5) months, 26 patients (92.9%) were free from AF without antiarrhythmic drugs after a mean of 1.4 ± 0.5 procedures per patient. Notably, recurrent arrhythmia was not observed in any patient (n = 6), wherein cTVT was terminated by additional radiofrequency applications inside an isolated area after the achievement of vein isolation.
  
  
  CONCLUSIONS
  Confined thoracic vein fibrillation is not a rare finding in patients with paroxysmal AF, and its elimination results in an excellent clinical outcome.
authors.affiliation: Cardiovascular Center, Tsuchiura Kyodo Hospital, Tsuchiura, Ibaraki, Japan. Electronic address: mshinsuke@k3.dion.ne.jp.
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Miyazaki
authors.affiliation: Cardiovascular Center, Tsuchiura Kyodo Hospital, Tsuchiura, Ibaraki, Japan.
authors.forename: Shigeki
authors.initials: S
authors.lastname: Kusa
authors.affiliation: Cardiovascular Center, Tsuchiura Kyodo Hospital, Tsuchiura, Ibaraki, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Taniguchi
authors.affiliation: Cardiovascular Center, Tsuchiura Kyodo Hospital, Tsuchiura, Ibaraki, Japan.
authors.forename: Jin
authors.initials: J
authors.lastname: Iwasawa
authors.affiliation: Cardiovascular Center, Tsuchiura Kyodo Hospital, Tsuchiura, Ibaraki, Japan.
authors.forename: Akio
authors.initials: A
authors.lastname: Kuroi
authors.affiliation: Cardiovascular Center, Tsuchiura Kyodo Hospital, Tsuchiura, Ibaraki, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Hachiya
authors.affiliation: Heart Rhythm Center, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Kenzo
authors.initials: K
authors.lastname: Hirao
authors.affiliation: Cardiovascular Center, Tsuchiura Kyodo Hospital, Tsuchiura, Ibaraki, Japan.
authors.forename: Yoshito
authors.initials: Y
authors.lastname: Iesaka
mesh_terms: D001281:Atrial Fibrillation / Q000453:epidemiology* / Q000503:physiopathology / Q000601:surgery; D017115:Catheter Ablation / Q000379:methods*; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006329:Heart Conduction System / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011667:Pulmonary Veins / Q000503:physiopathology* / Q000601:surgery; D013997:Time Factors; D016896:Treatment Outcome