title: Left ventricular twist and untwist in aortic stenosis.
abstract: BACKGROUND
  To optimally exploit the potential added diagnostic and prognostic value of new left ventricular (LV) deformation parameters, better understanding of LV mechanics in aortic stenosis (AS) is warranted. We sought to determine a broad spectrum of LV rotation parameters in AS patients and age-matched healthy controls, in order to gain insight into the mechanical properties of the LV in AS.
  
  
  METHODS
  The study comprised 48 AS patients with an aortic valve area<2.0 cm2 and LV ejection fraction>50%, and 24 healthy--for age and gender matched--control subjects. LV peak systolic rotation (Rotmax), LV peak systolic twist (Twistmax), untwisting rate (mean diastolic untwisting velocity from Twistmax to mitral valve opening), peak diastolic untwisting velocity, and time-to-peak diastolic untwisting velocity were determined by speckle tracking echocardiography.
  
  
  RESULTS
  AS patients had normal basal Rotmax and increased apical Rotmax, resulting in increased Twistmax (13.4±4.0° vs. 11.4±2.7°, P<0.05). Apical Rotmax and Twistmax correlated significantly to echo-Doppler indicators of AS severity. Time-to-peak diastolic untwisting velocity was increased (20±10% vs. 15±9%, P<0.05) and untwisting rate was decreased (-38±21°/s vs. -50±28°/s, P<0.01) in AS patients.
  
  
  CONCLUSIONS
  Twistmax increases proportionally to the severity of AS, which might serve as a compensatory mechanism to maintain systolic LV function. LV diastolic untwisting is delayed and the untwisting rate is reduced in AS.
authors.affiliation: Department of Cardiology, The Thoraxcenter, Erasmus University Medical Center, Rotterdam, The Netherlands.
authors.forename: Bas M
authors.initials: BM
authors.lastname: van Dalen
authors.forename: Apostolos
authors.initials: A
authors.lastname: Tzikas
authors.forename: Osama I I
authors.initials: OI
authors.lastname: Soliman
authors.forename: Floris
authors.initials: F
authors.lastname: Kauer
authors.forename: Helena J
authors.initials: HJ
authors.lastname: Heuvelman
authors.forename: Wim B
authors.initials: WB
authors.lastname: Vletter
authors.forename: Folkert J
authors.initials: FJ
authors.lastname: ten Cate
authors.forename: Marcel L
authors.initials: ML
authors.lastname: Geleijnse
mesh_terms: D000368:Aged; D001024:Aortic Valve Stenosis / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D012399:Rotation; D014463:Ultrasonography; D016277:Ventricular Function, Left / Q000502:physiology*