Individualizing the aorto-radial pressure transfer function: feasibility of a model-based approach

Am J Physiol Heart Circ Physiol. 2000 Aug;279(2):H542-9. doi: 10.1152/ajpheart.2000.279.2.H542.

Abstract

We fitted a three-segment transmission line model for the radial-carotid/aorta pressure transfer function (TFF) in 31 controls and 30 patients with coronary artery disease using noninvasively measured (tonometry) radial and carotid artery pressures (P(car)). Except for the distal reflection coefficient (0.85 +/- 0.21 in patients vs. 0.71 +/- 0.25 in controls; P < 0.05), model parameters were not different between patients or controls. Parameters were not related to blood pressure, age, or heart rate. We further assessed a point-to-point averaged TFF (TFF(avg)) as well as upper (TFF(max)) and lower (TFF(min)) enveloping TFF. Pulse pressure (PP) and augmentation index (AIx) were derived on original and reconstructed P(car) (P(car,r)). TFF(avg) yielded closest morphological agreement between P(car) and P(car,r) (root mean square = 4.3 +/- 2.3 mmHg), and TTF(avg) best predicted PP (41.5 +/- 11.8 vs. 41.1 +/- 10.0 mmHg measured) and AIx (-0.02 +/- 0.19 vs. 0.01 +/- 0.19). PP and AIx, calculated from P(car) or P(car,r), were higher in patients than in controls, irrespectively of the TFF used. We conclude that 1) averaged TFF yield significant discrepancies between reconstructed and measured pressure waveforms and subsequent derived AIx; and 2) different TFFs seem to preserve the information in the pressure wave that discriminates between controls and patients.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aorta / physiology*
  • Aorta / physiopathology
  • Blood Pressure / physiology*
  • Carotid Arteries / physiology*
  • Carotid Arteries / physiopathology
  • Coronary Disease / physiopathology*
  • Diastole
  • Heart Rate
  • Humans
  • Middle Aged
  • Models, Cardiovascular*
  • Muscle Tonus
  • Muscle, Smooth, Vascular / physiology
  • Muscle, Smooth, Vascular / physiopathology
  • Pulse
  • Radial Artery / physiology*
  • Radial Artery / physiopathology
  • Reference Values
  • Systole