title: Pulsed wave Doppler ultrasonography for the assessment of peripheral vasomotor response in an elderly population.
abstract: OBJECTIVE
  To assess sympathetic vasomotor activity and its changes with age, using pulsed wave Doppler ultrasound.
  
  
  METHODS
  We recruited 20 young adults (24-37 years old) and 20 older individuals (60-81 years old). Pulsed wave Doppler ultrasound was applied over the right radial artery to measure blood flow at rest and after a voluntary inspiratory cough eliciting sympathetic activation. The maximal (Vmax), minimal (Vmin), time-averaged (TAMaxV) blood flow velocity, and the pulsatility index (PI) were calculated and compared between groups.
  
  
  RESULTS
  At rest, PI was similar in both groups but Vmax and TAMaxV were higher in the older group (p < 0.05). Vmax, Vmin, and TAMaxV decreased, and PI increased after inspiratory cough in both groups (p ≤ 0.001), but this increase was lower in the older group (p < 0.001). TAMaxV after coughing was higher in the older group (p < 0.05). Heart rate did not differ significantly within or between groups.
  
  
  CONCLUSIONS
  The older group exhibited reduced vasomotor reactivity of the radial artery after sympathetic stimulus. Peripheral vasomotor response should be interpreted with caution in elderly populations.
authors.affiliation: Department of Physical Medicine and Rehabilitation, National Taiwan University Hospital and National Taiwan University College of Medicine, No. 7, Chun-San S. Rd., Taipei, 100, Taiwan, ROC.
authors.forename: Ke-Vin
authors.initials: KV
authors.lastname: Chang
authors.forename: Chueh-Hung
authors.initials: CH
authors.lastname: Wu
authors.forename: Tyng-Guey
authors.initials: TG
authors.lastname: Wang
authors.forename: Ming-Yen
authors.initials: MY
authors.lastname: Hsiao
authors.forename: Tian-Shin
authors.initials: TS
authors.lastname: Yeh
authors.forename: Wen-Shiang
authors.initials: WS
authors.lastname: Chen
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D000704:Analysis of Variance; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016491:Peripheral Vascular Diseases / Q000000981:diagnostic imaging / Q000503:physiopathology; D011673:Pulsatile Flow; D017534:Radial Artery; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric; D018617:Ultrasonography, Doppler, Pulsed; D014666:Vasomotor System / Q000000981:diagnostic imaging* / Q000503:physiopathology; D055815:Young Adult