title: Left atrial regional phasic strain, strain rate and velocity by speckle-tracking echocardiography: normal values and effects of aging in a large group of normal subjects.
abstract: BACKGROUND
  Two-dimensional (2D) speckle tracking echocardiography (STE) is a new tool for evaluation of LA function. The aims of this study are to establish the normal range of LA function measured by 2DSTE in different age groups and to evaluate the relations between the parameters of 2DSTE and Doppler echocardiography in evaluating LA and LV diastolic function in healthy adults.
  
  
  METHODS
  A total of 121 healthy volunteers (62 males, aged 47±15) were studied. The LA STE curves were obtained using R-wave onset of the electrocardiogram as a reference point. The LA strain during systolic, early and late diastole (εs, εa and εe = εr - εa); strain rate (SRs, SR, SRe and SRa); velocity (Vs, Ve and Va) were analyzed by commercialized software (EchoPAC). The differences between these parameters were analyzed in different age groups (≤35, 36-55 and ≥55 years) in both genders and compared with the corresponding Doppler echocardiographic indices.
  
  
  RESULTS
  Global LA εs, εe, and εa were 46.8±7.7, 27.3±6.4 and 19.6±4.2%; SRs, SRe, and SRa were 2.4±0.5, -2.4±0.7 and -2.8±0.6 1/s; Vs, Ve and Va were -5.3±0.9, 5.8±1.2 and 5.2±1.1cm/s respectively. The global LA 2DSTE parameters significantly correlated with Doppler echocardiographic indices which represented LA or LV diastolic function. Moreover, the STE LA parameters correlated significantly with age but not gender.
  
  
  CONCLUSIONS
  This study provides the normal range of LA strain, strain rate and velocity in 3 age groups, which are closely correlated with LA and LV function. The detailed assessment of LA phasic mechanics by 2DSTE may prove to be an important tool for future clinical studies.
authors.affiliation: Division of Cardiology, Department of Medicine and Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong; Institute of Vascular Medicine, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong; Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong; S.H. Ho Cardiovascular Disease and Stroke Centre, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong.
authors.forename: Jing Ping
authors.initials: JP
authors.lastname: Sun
authors.forename: Ying
authors.initials: Y
authors.lastname: Yang
authors.forename: Ran
authors.initials: R
authors.lastname: Guo
authors.forename: Dian
authors.initials: D
authors.lastname: Wang
authors.forename: Alex Pui-Wai
authors.initials: AP
authors.lastname: Lee
authors.forename: Xiao Yan
authors.initials: XY
authors.lastname: Wang
authors.forename: Yat-Yin
authors.initials: YY
authors.lastname: Lam
authors.forename: Fang
authors.initials: F
authors.lastname: Fang
authors.forename: Xing Sheng
authors.initials: XS
authors.lastname: Yang
authors.forename: Cheuk-Man
authors.initials: CM
authors.lastname: Yu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D016279:Atrial Function, Left / Q000502:physiology*; D004452:Echocardiography / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006325:Heart Atria / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D055815:Young Adult
keywords: Left atrial function; Reference values; Two-dimensional strain