title: Reduced and delayed untwisting of the left ventricle in patients with hypertension and left ventricular hypertrophy: a study using two-dimensional speckle tracking imaging.
abstract: OBJECTIVE
  Newly developed two-dimensional ultrasound speckle tracking imaging allows measurements of left ventricular (LV) rotation and twist. Because LV untwisting predominantly occurs during the isovolumic relaxation period, its assessment reflects the process of LV relaxation. The aim of this study was to examine whether LV hypertrophy (LVH) adversely affects LV untwisting and abnormalities in LV untwisting could become a novel marker in assessing LV relaxation abnormalities.
  
  
  RESULTS
  We acquired basal and apical LV short-axis images in 49 hypertensive patients. Using two-dimensional strain software, a time-domain speckle tracking was performed, and the mean value of LV rotation was obtained at each plane. LV twist was defined as apical rotation relative to the base. In order to adjust for inter-subject differences in heart rate, the time sequence was normalized to the percentage of systolic and diastolic duration. The degree of LV untwisting was calculated as the percentage of systolic twist : untwisting = (TwistES-Twistt/TwistES) x 100, where Twistt is twist at time t and TwistES is twist at end-systole. Although peak systolic twist was not different, early diastolic LV untwisting and untwisting rate during isovolumic relaxation period was significantly delayed and reduced in parallel to the severity of LVH, as assessed by LV mass index.
  
  
  CONCLUSIONS
  The observed delayed and reduced diastolic untwisting during the isovolumic relaxation period noted in hypertensive patients with LVH may contribute towards the LV relaxation abnormality. Two-dimensional speckle tracking imaging is a novel tool which can be used for the non-invasive assessment of LV relaxation.
authors.affiliation: Department of Cardiology and Internal Medicine, Tane General Hospital, 1-2-31 Sakaigawa, Nishi-ku, Osaka 550-0024, Japan. masaaki_takeuchi@hotmail.com
authors.forename: Masaaki
authors.initials: M
authors.lastname: Takeuchi
authors.forename: William B
authors.initials: WB
authors.lastname: Borden
authors.forename: Hiromi
authors.initials: H
authors.lastname: Nakai
authors.forename: Tomoko
authors.initials: T
authors.lastname: Nishikage
authors.forename: Michiko
authors.initials: M
authors.lastname: Kokumai
authors.forename: Toshiki
authors.initials: T
authors.lastname: Nagakura
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Otani
authors.forename: Roberto M
authors.initials: RM
authors.lastname: Lang
mesh_terms: D004452:Echocardiography / Q000379:methods; D004562:Electrocardiography; D005260:Female; D006801:Humans; D006973:Hypertension / Q000150:complications*; D017379:Hypertrophy, Left Ventricular / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D014102:Torsion Abnormality / Q000000981:diagnostic imaging / Q000503:physiopathology; D018487:Ventricular Dysfunction, Left / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology*; D016276:Ventricular Function