title: Differences in left ventricular twist related to age: speckle tracking echocardiographic data for healthy volunteers from neonate to age 70 years.
abstract: OBJECTIVE
  To determine normal left ventricular (LV) twist characteristics in different age groups and assess changes between neonates and the elderly.
  
  
  METHODS
  Short-axis left ventricle images at basal and apical levels were acquired in 274 healthy volunteers (aged 15 days to 72 years) by two-dimensional echocardiography, and were analyzed off-line using Speckle tracking echocardiography (STE) software to obtain LV twist measurements. The peak apical rotation (PAr), peak basal rotation (PBr), peak LV twist (Ptw), peak LV twist normalized by LV length (PtwN), peak untwisting velocity (PutwV), and isovolumic untwisting% (Iutw%) were measured.
  
  
  RESULTS
  LV twist values vary with age. Ptw was higher in older volunteers. PtwN varied inconsistently with age. PutwV and Iutw% were lower in the young and old with a peak in mid-age ranges.
  
  
  CONCLUSIONS
  STE is an effective noninvasive method to assess LV twist. Age-related differences in LV twist may reflect maturation and adaptive modulation of LV torsional biomechanics from neonate to the elderly.
authors.affiliation: Department of Ultrasound, the People's Hospital of HuNan province Changsha, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.forename: Qi-chang
authors.initials: QC
authors.lastname: Zhou
authors.forename: Da-rong
authors.initials: DR
authors.lastname: Pu
authors.forename: Lin
authors.initials: L
authors.lastname: Zou
authors.forename: Yi
authors.initials: Y
authors.lastname: Tan
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging; D002648:Child; D002675:Child, Preschool; D054459:Elasticity Imaging Techniques / Q000379:methods; D005260:Female; D006352:Heart Ventricles / Q000002:abnormalities / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D014102:Torsion Abnormality / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D055815:Young Adult