title: Cardiac cycle-dependent changes in aortic area and distensibility are reduced in older patients with isolated diastolic heart failure and correlate with exercise intolerance.
abstract: OBJECTIVE
  The goal of this study was to determine if cardiac cycle-dependent changes in proximal thoracic aortic area and distensibility are associated with exercise intolerance in elderly patients with diastolic heart failure (DHF).
  
  
  BACKGROUND
  Aortic compliance declines substantially with age. We hypothesized that a reduction in cardiac cycle-dependent changes in thoracic aortic area and distensibility (above that which occurs with aging) could be associated with the exercise intolerance that is prominent in elderly diastolic heart failure patients.
  
  
  METHODS
  Thirty subjects (20 healthy individuals [10 < 30 years of age and 10 > 60 years of age] and 10 individuals > the age of 60 years with DHF) underwent a magnetic resonance imaging (MRI) study of the heart and proximal thoracic aorta followed within 48 h by maximal exercise ergometry with expired gas analysis.
  
  
  RESULTS
  The patients with DHF had higher resting brachial pulse and systolic blood pressure, left ventricular mass, aortic wall thickness and mean aortic flow velocity, and, compared with healthy older subjects, they had a significant reduction in MRI-assessed cardiac cycle-dependent change in aortic area and distensibility (p < 0.0001) that correlated with diminished peak exercise oxygen consumption (r = 0.79). After controlling for age and gender in a multivariate analysis, thoracic aortic distensibility was a significant predictor of peak exercise oxygen consumption (p < 0.04).
  
  
  CONCLUSIONS
  Older patients with isolated DHF have reduced cardiac cycle-dependent changes in proximal thoracic aortic area and distensibility (beyond that which occurs with normal aging), and this correlates with and may contribute to their severe exercise intolerance.
authors.affiliation: Department of Internal Medicine, Cardiology Section, the Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157-1045, USA. ghundley@wfubmc.edu
authors.forename: W G
authors.initials: WG
authors.lastname: Hundley
authors.forename: D W
authors.initials: DW
authors.lastname: Kitzman
authors.forename: T M
authors.initials: TM
authors.lastname: Morgan
authors.forename: C A
authors.initials: CA
authors.lastname: Hamilton
authors.forename: S N
authors.initials: SN
authors.lastname: Darty
authors.forename: K P
authors.initials: KP
authors.lastname: Stewart
authors.forename: D M
authors.initials: DM
authors.lastname: Herrington
authors.forename: K M
authors.initials: KM
authors.lastname: Link
authors.forename: W C
authors.initials: WC
authors.lastname: Little
mesh_terms: D000328:Adult; D001013:Aorta, Thoracic / Q000473:pathology*; D004548:Elasticity; D005080:Exercise Test; D017079:Exercise Tolerance; D005260:Female; D006333:Heart Failure / Q000473:pathology* / Q000503:physiopathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D010101:Oxygen Consumption; D018487:Ventricular Dysfunction, Left / Q000473:pathology* / Q000503:physiopathology