title: Assessment of the morphology and mechanical function of the left atrial appendage by real-time three-dimensional transesophageal echocardiography.
abstract: BACKGROUND
  The left atrial appendage (LAA) is an important source of thrombus formation. We investigated the feasibility of the recently developed real-time three-dimensional transesophageal echocardiography (RT3D-TEE) method in assessment of the morphology and function of the LAA.
  
  
  METHODS
  Ninety-six consecutive patients (58 males with a mean age of (43.4 ± 12.5) years) who were referred for 2-dimensional (2D) transesophageal echocardiography (TEE) underwent additional RT3D-TEE. LAA morphology was visualized in multiple views. Orifice size, depth, volumes and ejection fraction (EF) of the LAA, were measured.
  
  
  RESULTS
  All the patients underwent RT3D-TEE examination without complications. Ninety-two patients (95.8%) had adequate images for visualization and quantitative analysis of the LAA. The LAA exhibited great variability with respect to relative dimensions and morphology. LAA orifice area was (3.8 ± 1.2) cm(2) with a diameter of (2.4 ± 0.9) cm × (1.4 ± 0.6) cm. The mean depth of the LAA was (2.9 ± 0.7) cm. End-diastolic volume (EDV-LAA), end-systolic volume (ESV-LAA) and EF of the LAA were (6.2 ± 3.7) ml, (4.1 ± 2.8) ml, and 0.35 ± 0.16, respectively. EDV-LAA, ESV-LAA and the orifice area of the LAA in patients with atrial fibrillation (AF) were larger than those without AF, whereas the EF was smaller in the AF patients.
  
  
  CONCLUSIONS
  Defining LAA morphology and quantitative analysis of the size and function of the LAA with superior quality and resolution of images using RT3D-TEE is feasible. This technique may be an ideal tool for guidance of the LAA occlusion procedure. Determination of LAA volumes and volume-derived EF by RT3D-TEE provides new insights into the analysis of LAA function.
authors.affiliation: Department of Echocardiography, State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100037, China.
authors.forename: Ou-di
authors.initials: OD
authors.lastname: Chen
authors.forename: Wei-Chun
authors.initials: WC
authors.lastname: Wu
authors.forename: Yong
authors.initials: Y
authors.lastname: Jiang
authors.forename: Ming-Hu
authors.initials: MH
authors.lastname: Xiao
authors.forename: Hao
authors.initials: H
authors.lastname: Wang
mesh_terms: D000328:Adult; D020517:Atrial Appendage / Q000000981:diagnostic imaging*; D019560:Echocardiography, Three-Dimensional / Q000379:methods*; D017548:Echocardiography, Transesophageal / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged