title: Reduced low-frequency heart rate variability relates to greater intimal-medial thickness of the carotid wall in two samples.
abstract: BACKGROUND
  We investigated the relationship between heart rate variability and preclinical carotid intima-media thickening, a putative index of atherosclerosis.
  
  
  METHODS
  A sample of 350 men and women (mean age 56.8 years) selected for the presence or absence of untreated hypertension was assessed for heart rate variability at rest and separately for carotid intima-media thickness using duplex ultrasonography (Pittsburgh study). Findings from this sample were cross-validated in a subsample of 68 men drawn from the Kuopio Ischemic Heart Disease Risk Factor trial and selected for the presence or absence of angina.
  
  
  RESULTS
  In both samples, regression analyses, controlling for known risk factors, showed a significant negative relationship between mean carotid intima-media thickness and low-frequency (0.05-0.15 Hz) heart rate variability, but not high-frequency variability.
  
  
  CONCLUSIONS
  The mechanism underlying this relationship remains unclear. The absence of difference in high-frequency variation questions any interpretation in terms of vagal function; the difference in low-frequency variation may implicate vessel wall characteristics or decreased sympathetic nervous system influence.
  
  
  CONCLUSIONS
  Decreased amplitude of low-frequency heart rate variability seems associated with a preclinical atherosclerotic index.
authors.affiliation: Department of Psychiatry and Psychology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA.
authors.forename: Clara
authors.initials: C
authors.lastname: Gautier
authors.forename: Lynn
authors.initials: L
authors.lastname: Stine
authors.forename: J Richard
authors.initials: JR
authors.lastname: Jennings
authors.forename: Kim
authors.initials: K
authors.lastname: Sutton-Tyrrell
authors.forename: Matthew B
authors.initials: MB
authors.lastname: Muldoon
authors.forename: Thomas W
authors.initials: TW
authors.lastname: Kamarck
authors.forename: George A
authors.initials: GA
authors.lastname: Kaplan
authors.forename: Jukka
authors.initials: J
authors.lastname: Salonen
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Manuck
mesh_terms: D000328:Adult; D000368:Aged; D001161:Arteriosclerosis / Q000175:diagnosis / Q000453:epidemiology; D002340:Carotid Artery Diseases / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000503:physiopathology; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging*; D005260:Female; D006339:Heart Rate; D006801:Humans; D006973:Hypertension / Q000175:diagnosis / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D017539:Tunica Intima / Q000000981:diagnostic imaging* / Q000503:physiopathology; D017540:Tunica Media / Q000000981:diagnostic imaging* / Q000503:physiopathology; D014463:Ultrasonography