title: Posterior left atrial-esophageal relationship throughout the cardiac cycle.
abstract: BACKGROUND
  Radiofrequency energy delivered throughout the cardiac cycle has the potential to cause thermal injury to the esophagus if the anatomical relationship between the posterior left atrium and the esophagus changes during cardiac motion.
  
  
  OBJECTIVE
  To assess the posterior left atrial-esophageal relationship throughout the cardiac cycle.
  
  
  METHODS
  In this study, the anatomical relationship between the posterior left atrium and the esophagus was assessed throughout the cardiac cycle in 10 consecutive patients. All patients underwent contrast-enhanced, ECG-gated CT scanning. Left atrial volumes and the esophageal structure were generated from the reconstructed data at 10 phases of the cardiac cycle from 5% to 95% of the R-R interval. The posterior left atrial-esophageal anatomical relationship was measured at four levels, the superior pulmonary vein ostial site, and the upper, mid and lower left atrium.
  
  
  RESULTS
  There were significant variations in the left atrial-esophageal relationship in the 10 patients. The relative movement between the esophagus and the posterior left atrium throughout the cardiac cycle in the anteroposterior and right-to-left orientations was 0.55 +/- 0.99 mm and 0.60 +/- 1.02 mm (95% confidence interval, 2.03 and 1.98 respectively).
  
  
  CONCLUSIONS
  Under normal conditions, there is little change in the anatomical relationship between the posterior left atrium and the esophagus during the entire cardiac cycle. However, due to the interpatient variability at the esophageal location, identification of esophageal location may help prevent complications during catheter ablation procedures involving the left atrium.
authors.affiliation: Electrophysiology Laboratories, Aurora Sinai/St. Luke's Medical Centers, University of Wisconsin School of Medicine and Public Health-Milwaukee Clinical Campus, Milwaukee, Wisconsin, USA. bdanek@hrtcare.com
authors.forename: Jasbir
authors.initials: J
authors.lastname: Sra
authors.forename: David
authors.initials: D
authors.lastname: Krum
authors.forename: Angela
authors.initials: A
authors.lastname: Malloy
authors.forename: Atul
authors.initials: A
authors.lastname: Bhatia
authors.forename: Ryan
authors.initials: R
authors.lastname: Cooley
authors.forename: Zalmen
authors.initials: Z
authors.lastname: Blanck
authors.forename: Anwer
authors.initials: A
authors.lastname: Dhala
authors.forename: Alfred J
authors.initials: AJ
authors.lastname: Anderson
authors.forename: Masood
authors.initials: M
authors.lastname: Akhtar
mesh_terms: D000328:Adult; D001281:Atrial Fibrillation / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D016275:Atrial Function; D003287:Contrast Media; D003971:Diastole / Q000502:physiology; D004452:Echocardiography; D004562:Electrocardiography; D004947:Esophagus / Q000033:anatomy & histology* / Q000000981:diagnostic imaging* / Q000502:physiology; D005260:Female; D006325:Heart Atria / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D013599:Systole / Q000502:physiology; D014057:Tomography, X-Ray Computed
chemical_list: D003287:Contrast Media