title: Regional LV deformation in healthy individuals during isovolumetric contraction and ejection phases assessed by 2D speckle tracking echocardiography.
abstract: OBJECTIVE
  The main purpose of the this human study was by speckle tracking imaging to characterize the regional and temporal distribution of normal left ventricular (LV) deformation and the LV geometry during isovolumetric contraction (IVC) and the ejection phase.
  
  
  METHODS
  Twelve healthy young men [22 (2·3) years] were included. Longitudinal and circumferential strain and local twist angle were measured at four LV short-axis levels: basal, papillary, subpapillary and apical level during IVC and ejection phases. In addition, LV length from apex to the atrio-ventricular level, two diameters at LV basal short-axis level and atrio-ventricular plane displacement (AVPD) were measured to characterize LV shape during IVC.
  
  
  RESULTS
  During IVC, longitudinal and circumferential shortening was demonstrated at all four short-axis levels from base to apex, while the LV made a basal counterclockwise and apical clockwise rotation representing untwist. In addition, there was a reduction in LV length and changes in short-axis diameters at basal level and AVPD from end-diastole to end-IVC, reflecting that the LV changed from an oval to a more spherical shape. At end-systole, longitudinal and circumferential shortening and local twist angle were significantly increased towards apex (P<0·05).
  
  
  CONCLUSIONS
  This study demonstrated that the IVC in healthy humans is characterized by regional longitudinal and circumferential shortening and LV untwist, which occurs parallel to geometric changes of the LV into a spherical shape. During ejection, increased regional gradients of LV deformation towards apex in LV longitudinal and circumferential shortening and local and net twist angle were demonstrated.
authors.affiliation: Department of Cardiology, Oslo University Hospital HF and Faculty of Medicine, University of Oslo, Oslo, Norway. anders.hodt@medisin.uio.no
authors.forename: Anders
authors.initials: A
authors.lastname: Hodt
authors.forename: Marie
authors.initials: M
authors.lastname: Stugaard
authors.forename: Jonny
authors.initials: J
authors.lastname: Hisdal
authors.forename: Einar
authors.initials: E
authors.lastname: Stranden
authors.forename: Dan
authors.initials: D
authors.lastname: Atar
authors.forename: Kjetil
authors.initials: K
authors.lastname: Steine
mesh_terms: D000704:Analysis of Variance; D001696:Biomechanical Phenomena; D015150:Echocardiography, Doppler; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D009200:Myocardial Contraction; D009664:Norway; D011237:Predictive Value of Tests; D012016:Reference Values; D015203:Reproducibility of Results; D013318:Stroke Volume; D013997:Time Factors; D016277:Ventricular Function, Left; D055815:Young Adult