title: Pulse wave velocity and flow in the carotid artery versus the aortic arch: effects of aging.
abstract: OBJECTIVE
  To explore differences in arterial stiffness of the aorta and carotid artery, assessed by pulse wave velocity (PWV), to evaluate the blood flow volume distribution towards the carotid circulation and to assess the effect of aging on the coupling between aortic and carotid PWV using velocity-encoded magnetic resonance imaging (MRI).
  
  
  METHODS
  Sixteen adult younger volunteers (age <30 years) and 16 older volunteers (age >45 years) underwent 3T MRI examination to assess aortic and carotid flow volumes and PWV using the transit time method.
  
  
  RESULTS
  Aortic versus carotid PWV-ratio was 1.2 for younger volunteers and 0.95 for older volunteers, demonstrating leveling of wall stiffness. Furthermore, flow volume per minute in the internal carotid artery was lower for older versus younger volunteers (mean volume 177 ± 42 mL/min/m(2) vs. 147 ± 32 mL/min/m(2), P = 0.028), whereas aorta and common carotid artery flow volumes were not different. Consequently, the fraction of blood flow volume towards the brain was smaller for older versus younger volunteers (61 ± 9% versus 71 ± 8%, P = 0.002).
  
  
  CONCLUSIONS
  PWV-leveling between aorta and carotid artery at older age is associated with a reduction in blood flow volume towards the brain. Velocity-encoded MRI can be used to evaluate PWV and flow volume distribution in the aortic arch and the carotid circulation.
authors.affiliation: Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands; Interuniversity Cardiology Institute of The Netherlands, Utrecht, The Netherlands.
authors.forename: Eleanore S J
authors.initials: ES
authors.lastname: Kröner
authors.forename: Hildo J
authors.initials: HJ
authors.lastname: Lamb
authors.forename: Hans-Marc J
authors.initials: HM
authors.lastname: Siebelink
authors.forename: Suzanne C
authors.initials: SC
authors.lastname: Cannegieter
authors.forename: Pieter J
authors.initials: PJ
authors.lastname: van den Boogaard
authors.forename: Ernst E
authors.initials: EE
authors.lastname: van der Wall
authors.forename: Albert
authors.initials: A
authors.lastname: de Roos
authors.forename: Jos J M
authors.initials: JJ
authors.lastname: Westenberg
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D001013:Aorta, Thoracic / Q000502:physiology*; D001783:Blood Flow Velocity / Q000502:physiology*; D002339:Carotid Arteries / Q000502:physiology*; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011673:Pulsatile Flow / Q000502:physiology*; D063177:Pulse Wave Analysis / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult
keywords: aging; aorta; carotid artery; flow; pulse wave velocity