title: Asynchronous arterial systolic expansion as a marker of vascular aging:  assessment of the carotid artery with velocity vector imaging.
abstract: OBJECTIVE
  Arterial elastic properties change with aging. Measurements of pulse wave velocity and augmentation index are useful for the evaluation of arterial stiffness. However, they likely represent only global characteristics of the arterial tree rather than local vascular alterations. The aim of this study was to evaluate whether local vascular properties assessed by velocity vector imaging differed with aging.
  
  
  METHODS
  Vascular properties of carotid arteries with ages were assessed in 100 healthy volunteers (52 men) ranging from 20 to 68 years using velocity vector imaging. The peak circumferential strain and strain rate of the six segments in left common carotid arteries were analyzed and the standard deviation of the time to peak circumferential strain and strain rate of the six segments, representing the synchronicity of the arterial expansion, were calculated. Central blood pressure, augmentation index and pulse wave velocity were assessed by commercially available radial artery tonometry, the SphygmoCor system (AtCor Medical, West Ryde, Australia). A validated generalized transfer function was used to acquire the central aortic pressures and pressure waveforms.
  
  
  RESULTS
  Pulse wave velocity, augmentation index and velocity vector imaging parameters showed significant changes with age. However, the age-related changes in pulse wave velocity, augmentation index and velocity vector imaging parameters were different. The increase in pulse wave velocity was more prominent in older individuals, whereas the changes in augmentation index and carotid strain and strain rate were evident earlier, at the age of 30 years. Unlike augmentation index, which showed little change in older individuals, the standard deviation of time to peak strain and strain rate showed a steady increase from younger to older individuals.
  
  
  CONCLUSIONS
  Asynchronous arterial expansion could be a useful discriminative marker of vascular aging independent of individual's age.
authors: Cardiology Division, Severance Cardiovascular Hospital, Severance Biomedical Science Institute, Yonsei University College of Medicine, Seodaemun-gu, Seoul, Republic of Korea.
authors: Woo-In
authors: WI
authors: Yang
authors: Chi Y
authors: CY
authors: Shim
authors: Woo D
authors: WD
authors: Bang
authors: Chang M
authors: CM
authors: Oh
authors: Hyuk J
authors: HJ
authors: Chang
authors: Namsik
authors: N
authors: Chung
authors: Jong-Won
authors: JW
authors: Ha
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D001783:Blood Flow Velocity / Q000502:physiology*; D001794:Blood Pressure / Q000502:physiology; D002339:Carotid Arteries / Q000000981:diagnostic imaging / Q000503:physiopathology*; D002340:Carotid Artery Diseases / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000503:physiopathology; D004548:Elasticity / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008365:Manometry; D008875:Middle Aged; D017534:Radial Artery / Q000503:physiopathology; D013599:Systole / Q000502:physiology*; D013997:Time Factors; D014463:Ultrasonography; D014655:Vascular Resistance / Q000502:physiology*; D059289:Vascular Stiffness / Q000502:physiology; D014664:Vasodilation; D055815:Young Adult