title: Impact of aortic encroachment to left atrium on non-pulmonary vein triggers of atrial fibrillation.
abstract: BACKGROUND
  Aortic dilatation was frequently observed in patients with atrial fibrillation (AF) and non-pulmonary vein (PV) triggers are important for mapping and ablation of AF. We hypothesized that the aortic encroachment area over left atrium (LA) could contribute to the local substrate characteristics.
  
  
  METHODS
  We studied 32 consecutive patients of AF (age=57.34±8.07, male=30), including 26 paroxysmal and 6 persistent AFs. Anatomic relationship between LA and aorta, and electrophysiological characteristics of the encroachment areas were investigated. IRB approval was taken.
  
  
  RESULTS
  The LA bipolar voltage (mean 0.49±0.26mV) was lower at aortic encroached area compared to global LA (mean 1.52±0.48mV) and it was statistically significant (p<0.001). There was a linear correlation between the voltages of LA and distance from the aorta to the aortic encroachment area of LA (p<0.001, R=0.616). Non-PV triggers were observed in 34.37% (n=11) of total patients. The initiation of AF in aortic encroached area was seen in 45.45% (n=5) of non-PV trigger and 15.62% of total patients. All the patients were followed up for 6months and 4 (14.81%) out of 27 patients without trigger at aortic encroached site of LA and 1 (20%) out of 5 patients with trigger at aortic encroached site of LA had recurrence of AF.
  
  
  CONCLUSIONS
  The aorta contributed to low voltages on its encroachment area over the anterior wall of LA. Non-pulmonary vein triggers originating from the aortic encroachment area were found in 15.62% of total patients. Careful evaluation of the anatomical relationship between LA and aorta is important during AF ablation for a better long term outcome.
authors.affiliation: Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; Nizam's Institute of Medical Sciences, Hyderabad, India.
authors.forename: Suresh
authors.initials: S
authors.lastname: Allamsetty
authors.affiliation: Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; Institute of Clinical Medicine, and Cardiovascular Research Centre, National Yang-Ming University, Taiwan.
authors.forename: Li-Wei
authors.initials: LW
authors.lastname: Lo
authors.affiliation: Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; Institute of Clinical Medicine, and Cardiovascular Research Centre, National Yang-Ming University, Taiwan.
authors.forename: Yenn-Jiang
authors.initials: YJ
authors.lastname: Lin
authors.affiliation: Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; Institute of Clinical Medicine, and Cardiovascular Research Centre, National Yang-Ming University, Taiwan.
authors.forename: Shih-Lin
authors.initials: SL
authors.lastname: Chang
authors.affiliation: Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; Institute of Clinical Medicine, and Cardiovascular Research Centre, National Yang-Ming University, Taiwan.
authors.forename: Fa-Po
authors.initials: FP
authors.lastname: Chung
authors.affiliation: Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; Institute of Clinical Medicine, and Cardiovascular Research Centre, National Yang-Ming University, Taiwan.
authors.forename: Yu-Feng
authors.initials: YF
authors.lastname: Hu
authors.affiliation: Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.
authors.forename: Chin-Yu
authors.initials: CY
authors.lastname: Lin
authors.affiliation: Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; Institute of Clinical Medicine, and Cardiovascular Research Centre, National Yang-Ming University, Taiwan.
authors.forename: Yao-Ting
authors.initials: YT
authors.lastname: Chang
authors.affiliation: Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.
authors.forename: Cheng-Hung
authors.initials: CH
authors.lastname: Chiang
authors.affiliation: Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.
authors.forename: Hung-Kai
authors.initials: HK
authors.lastname: Huang
authors.affiliation: Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.
authors.forename: Chao-Shun
authors.initials: CS
authors.lastname: Chan
authors.affiliation: Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.
authors.forename: Van Bun Dan
authors.initials: VBD
authors.lastname: Do
authors.affiliation: Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.
authors.forename: Chung-Hsing
authors.initials: CH
authors.lastname: Lin
authors.affiliation: Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.
authors.forename: Sunu
authors.initials: S
authors.lastname: Raharjo
authors.affiliation: Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.
authors.forename: Shih-Jee
authors.initials: SJ
authors.lastname: Jhuo
authors.affiliation: Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.
authors.forename: Rohit
authors.initials: R
authors.lastname: Walia
authors.affiliation: Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; Institute of Clinical Medicine, and Cardiovascular Research Centre, National Yang-Ming University, Taiwan. Electronic address: epsachen@ms41.hinet.net.
authors.forename: Shih-Ann
authors.initials: SA
authors.lastname: Chen
mesh_terms: D000368:Aged; D001011:Aorta / Q000000981:diagnostic imaging* / Q000503:physiopathology; D001281:Atrial Fibrillation / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D005500:Follow-Up Studies; D006325:Heart Atria / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011667:Pulmonary Veins; D014057:Tomography, X-Ray Computed
keywords: Aorta; Atrial fibrillation; Encroachment; Left atrium; Trigger