title: Role of arrhythmogenic superior vena cava on atrial fibrillation.
abstract: BACKGROUND
  It is well known that superior vena cava (SVC) is one of the important non-pulmonary vein (PV) foci of atrial fibrillation (AF). However, little is known regarding the role of arrhythmogenic SVC in AF.
  
  
  RESULTS
  Among 1,425 patients who underwent AF ablation in 2 centers, PV antrum isolation was performed in all and SVC isolation was added in 74 (5.2%) patients with arrhythmogenic SVC (58 ± 10 years; 54 males) when the latter was identified as an AF source. The arrhythmogenicity was identified at the 1st, 2nd, and 3rd procedures in 62 (83.8%), 7 (9.5%), and 5 (6.7%) patients, respectively. In 7 (9.5%), 26 (35.1%), and 14 (18.9%) patients, it was identified following adenosine injection, isoproterenol infusion, and electrical cardioversion, respectively. SVC triggering AF was identified in 58 out of 74 (78.4%) patients. In this subset, AF initiated from SVC; however, AF cycle length was longer in SVC than in the right atrium once AF persisted, which suggested its role as an initiator. In 24 (32.4%) patients following the isolation of SVC, AF terminated or converted to atrial flutter and/or confined SVC tachycardia/fibrillation was observed, which suggested its role as a perpetuator. Sixty-four (86.5%) of 74 patients were free from any atrial tachyarrhythmias without antiarrhythmic drugs mean 12.1 ± 9.4 months after the last ablation procedure (mean 1.38 procedures/patient).
  
  
  CONCLUSIONS
  In a subset of patients, SVC plays a role in AF not only as an initiator/trigger but also as a driver/perpetuator.
authors: Cardiovascular Center, Tsuchiura Kyodo Hospital, Ibaraki, Japan.
authors: Shinsuke
authors: S
authors: Miyazaki
authors: Cardiovascular Center, Yokosuka Kyosai Hospital, Kanagawa, Japan.
authors: Masateru
authors: M
authors: Takigawa
authors: Cardiovascular Center, Tsuchiura Kyodo Hospital, Ibaraki, Japan.
authors: Shigeki
authors: S
authors: Kusa
authors: Cardiovascular Center, Yokosuka Kyosai Hospital, Kanagawa, Japan.
authors: Taishi
authors: T
authors: Kuwahara
authors: Cardiovascular Center, Tsuchiura Kyodo Hospital, Ibaraki, Japan.
authors: Hiroshi
authors: H
authors: Taniguchi
authors: Cardiovascular Center, Yokosuka Kyosai Hospital, Kanagawa, Japan.
authors: Kenji
authors: K
authors: Okubo
authors: Cardiovascular Center, Tsuchiura Kyodo Hospital, Ibaraki, Japan.
authors: Hiroaki
authors: H
authors: Nakamura
authors: Cardiovascular Center, Tsuchiura Kyodo Hospital, Ibaraki, Japan.
authors: Hitoshi
authors: H
authors: Hachiya
authors: Heart Rhythm Center, Tokyo Medical and Dental University, Tokyo, Japan.
authors: Kenzo
authors: K
authors: Hirao
authors: Cardiovascular Center, Yokosuka Kyosai Hospital, Kanagawa, Japan.
authors: Atsushi
authors: A
authors: Takahashi
authors: Cardiovascular Center, Tsuchiura Kyodo Hospital, Ibaraki, Japan.
authors: Yoshito
authors: Y
authors: Iesaka
mesh_terms: D000368:Aged; D001145:Arrhythmias, Cardiac / Q000503:physiopathology*; D001281:Atrial Fibrillation / Q000503:physiopathology*; D017115:Catheter Ablation; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011667:Pulmonary Veins / Q000503:physiopathology; D012086:Reoperation; D012189:Retrospective Studies; D014683:Vena Cava, Superior / Q000503:physiopathology*
keywords: atrial fibrillation; catheter ablation; pulmonary vein isolation; superior vena cava; trigger