title: Evaluating the Hemodynamic Basis of Age-Related Central Blood Pressure Change Using Aortic Flow Triangulation.
abstract: BACKGROUND
  Pulsatile blood pressure rises with age, especially in the aorta. The comparative role of forward and reflected pressure waves (FW and RW, respectively), determined by aortic flow triangulation has not previously been explored in a large clinical cohort. This study aimed to identify the role of FW and RW in the rise in aortic pulse pressure with age.
  
  
  METHODS
  For 879 outpatients, aortic pressure waveforms were generated using a validated generalized transfer function applied to radial pressure waves recorded using applanation tonometry. FW and RW were subsequently determined using aortic flow triangulation. Contributions of FW and RW to rise in aortic pulse pressure with age were determined using multivariate linear regression and product of coefficient mediation analysis, with adjustment for height, weight, heart rate, and mean arterial pressure. Comparisons were made by gender and before and after age 60.
  
  
  RESULTS
  In subjects aged 60 and below, RW was an important contributor to pulsatile pressure elevation with age, but FW was non-contributory in either gender after multivariate correction. In subjects aged above 60, both FW and RW were significant and equal contributors in both genders.
  
  
  CONCLUSIONS
  In a clinical setting, both FW and RW are important to pulsatile aortic blood pressure across the lifespan, but RW appears to have a more pronounced effect across all ages, whereas FW has less effect in younger persons.
authors.affiliation: Department of Cardiology, St. Vincent's Hospital and Clinic, Sydney, Australia; Faculty of Medicine, University of New South Wales, Sydney Australia; Vascular-Ventricular Interactions Laboratory, Cardiac Physiology and Transplantation Division, Victor Chang Cardiac Research Institute, Sydney, Australia;
authors.forename: Mayooran
authors.initials: M
authors.lastname: Namasivayam
authors.affiliation: Department of Cardiology, St. Vincent's Hospital and Clinic, Sydney, Australia; Vascular-Ventricular Interactions Laboratory, Cardiac Physiology and Transplantation Division, Victor Chang Cardiac Research Institute, Sydney, Australia; Australian School of Advanced Medicine, Macquarie University, Sydney, Australia.
authors.forename: Audrey
authors.initials: A
authors.lastname: Adji
authors.affiliation: Department of Cardiology, St. Vincent's Hospital and Clinic, Sydney, Australia; Faculty of Medicine, University of New South Wales, Sydney Australia; Vascular-Ventricular Interactions Laboratory, Cardiac Physiology and Transplantation Division, Victor Chang Cardiac Research Institute, Sydney, Australia; m.orourke@unsw.edu.au.
authors.forename: Michael F
authors.initials: MF
authors.lastname: O'Rourke
mesh_terms: D000375:Aging / Q000502:physiology*; D001794:Blood Pressure; D003430:Cross-Sectional Studies; D003935:Diagnostic Techniques, Cardiovascular; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged
keywords: aging; arterial stiffness; blood pressure; central pressure; hemodynamics; hypertension; wave reflection.