title: Analysis of femoral artery intima-media thickness during the cardiac cycle.
abstract: BACKGROUND
  Variations in the intima-media thickness (IMT) of the carotid artery during the cardiac cycle are well established. The change in femoral IMT during the cardiac cycle is largely unknown. This study focuses on the variation of femoral IMT, vessel diameter, and cross-sectional area (CSA) of the IMT during the cardiac cycle.
  
  
  METHODS
  Video clips of the femoral artery were obtained using B-mode ultrasonography in 60 patients between the ages of 18 and 50. IMT and diameter measurements were made using automated software, and CSA was subsequently calculated. Triplicate measurements of each femoral artery were made at three points in the cardiac cycle: the R wave, the T wave, and at the point of maximal vessel diameter falling after the T wave and before the following P wave.
  
  
  RESULTS
  Femoral IMT, diameter, and CSA did not show a statistically significant difference with measurement on the R versus the T wave (P>0.36, P>0.28, and P>0.76, respectively). Interestingly, when comparing measurements on the R or T wave with measurements taken at the maximum vessel diameter, there was a statistically significant difference in vessel diameter (P<0.001) and CSA (P<0.005) but not in femoral IMT (P>0.2).
  
  
  CONCLUSIONS
  Unlike studies of the carotid artery, there were no statistically significant differences between measurements made at the R versus the T wave. There were, however, statistically significant differences noted in diameter and CSA when measurements were taken at a point later in the cardiac cycle. This has ramifications for future studies on vascular remodeling.
authors.affiliation: Division of Vascular Surgery and Endovascular Therapy, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania, USA.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Layne
authors.forename: Ronald M
authors.initials: RM
authors.lastname: Fairman
authors.forename: Benjamin M
authors.initials: BM
authors.lastname: Jackson
authors.forename: Edward Y
authors.initials: EY
authors.lastname: Woo
authors.forename: Julia T
authors.initials: JT
authors.lastname: Davis
authors.forename: Emile R
authors.initials: ER
authors.lastname: Mohler
authors.forename: Grace J
authors.initials: GJ
authors.lastname: Wang
mesh_terms: D000293:Adolescent; D000328:Adult; D005263:Femoral Artery / Q000000981:diagnostic imaging / Q000502:physiology*; D006321:Heart / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D017539:Tunica Intima / Q000000981:diagnostic imaging / Q000502:physiology*; D017540:Tunica Media / Q000000981:diagnostic imaging / Q000502:physiology*; D014463:Ultrasonography; D055815:Young Adult