title: Radial deformation by tissue Doppler imaging in multiple myocardial layers.
abstract: OBJECTIVE
  Measuring strain in multiple myocardial layers using 2-dimensional tissue Doppler imaging may provide valuable diagnostic information about non-transmural disease. However, its feasibility in humans has not been demonstrated previously, and optimal machine settings not defined.
  
  
  METHODS
  From parasternal short axis, zoomed tissue Doppler imaging of the left ventricular inferior wall was obtained in 23 young, healthy humans. Images were recorded with six different machine settings. Velocity, strain rate and strain were measured in two and three layers across the wall.
  
  
  RESULTS
  For two-layer-measurements, all subendocardial values were significantly higher than the subepicardial ones (p<0.003 for all data sets). Minimal radial and maximal lateral averaging resulted in largest strain differences: 106.4+/-32.6% (mean+/-SD) subendocardially versus 54.2+/-20.1% subepicardially. By similar settings in three layers, strain was 105.7+/-34.5% subendocardially, 81.2+/-26.9% midmyocardially and 48.3+/-26.9% subepicardially (p <0.05).
  
  
  CONCLUSIONS
  We have demonstrated that it is feasible to measure radial velocity, strain rate and strain in up to three individual layers in young healthy humans, and the diagnostic potentials should be tested on patient groups.
authors.affiliation: Department of Heart Disease, Haukeland University Hospital, Bergen, Norway. einar.davidsen@helse-bergen.no
authors.forename: Einar Skulstad
authors.initials: ES
authors.lastname: Davidsen
authors.forename: Christian Arvei
authors.initials: CA
authors.lastname: Moen
authors.forename: Knut
authors.initials: K
authors.lastname: Matre
mesh_terms: D000328:Adult; D018618:Echocardiography, Doppler, Color; D005240:Feasibility Studies; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D009200:Myocardial Contraction; D015588:Observer Variation; D010865:Pilot Projects; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D016277:Ventricular Function, Left; D055815:Young Adult