title: The feasibility of velocity vector imaging by transesophageal echocardiography for assessment of elastic properties of the descending aorta in aortic valve disease.
abstract: BACKGROUND
  Velocity vector imaging (VVI) is a novel two-dimensional speckle-based imaging technique for evaluation of tissue deformation. The aim of this study was to determine the feasibility and variability of VVI for the assessment of aortic strain, distensibility, and stiffness in patients with aortic valve disease.
  
  
  METHODS
  Eighty-five patients (mean age 66 +/- 11 years) with aortic stenosis (AS) or aortic regurgitation (AR) were examined in the operating room before the operation using transesophageal echocardiography (TEE). The two-dimensional short-axis images and M-mode recordings of the descending aorta were acquired simultaneously with the invasive blood pressure measurement in the radial artery. The TEE images were analyzed off-line using VVI software.
  
  
  RESULTS
  In comparison with patients with AS, patients with AR displayed significantly higher circumferential strain (7.6% +/- 4.5% vs. 3.7% +/- 1.9%, P < .001) and distensibility (27.1 +/- 12.8 kPa(-1)10(-3) vs. 17.2 +/- 7.2 kPa(-1)10(-3), P < .001) by VVI and distensibility (32.8 +/- 16.7 kPa(-1)10(-3) vs. 21.7 +/- 10.6 kPa(-1)10(-3), P < .004) by M-mode. Stiffness was higher in AS than AR, as measured by VVI (13.3 +/- 6.0 vs. 10.5 +/- 6.0, P < .01) and M-mode (11.2 +/- 6.1 vs. 10.4 +/- 9.1, P < .048). The correlations between VVI and M-mode distensibility (r = 0.84) and stiffness (r = 0.84) were both highly significant (P < .0001). The VVI strain measurements showed low inter- and intraobserver variability with intraclass correlations greater than 0.95 and coefficients of variation less than 10%.
  
  
  CONCLUSIONS
  VVI-derived strain, distensibility, and stiffness differ significantly between AR and AS and correlate strongly with the corresponding M-mode-derived parameters. VVI is a feasible method for the assessment of the elastic properties of the descending aorta with low variability and has the advantage of incorporating the entire aortic wall circumference in the analysis, consequently accounting for local variations in the elastic properties of the aorta.
authors.affiliation: Department of Clinical Physiology, Karolinska University Hospital, Stockholm, Sweden. johan.petrini@karolinska.se
authors.forename: Johan
authors.initials: J
authors.lastname: Petrini
authors.forename: Mohamed
authors.initials: M
authors.lastname: Yousry
authors.forename: Anette
authors.initials: A
authors.lastname: Rickenlund
authors.forename: Jan
authors.initials: J
authors.lastname: Liska
authors.forename: Anders
authors.initials: A
authors.lastname: Hamsten
authors.forename: Per
authors.initials: P
authors.lastname: Eriksson
authors.forename: Anders
authors.initials: A
authors.lastname: Franco-Cereceda
authors.forename: Kenneth
authors.initials: K
authors.lastname: Caidahl
authors.forename: Maria J
authors.initials: MJ
authors.lastname: Eriksson
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D001013:Aorta, Thoracic / Q000000981:diagnostic imaging* / Q000503:physiopathology; D001022:Aortic Valve Insufficiency / Q000000981:diagnostic imaging* / Q000503:physiopathology; D001024:Aortic Valve Stenosis / Q000000981:diagnostic imaging* / Q000503:physiopathology; D016009:Chi-Square Distribution; D017548:Echocardiography, Transesophageal / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D016014:Linear Models; D008297:Male; D011446:Prospective Studies; D015203:Reproducibility of Results; D012984:Software