Development and Validation of a Noninvasive Method to Determine Arterial Pressure and Vascular Compliance

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Abstract

The ability not only to record automated systolic and diastolic pressure, but also to derive measurements of the rate of pressure change during the cardiac cycle, would have great potential clinical value. A new method has been developed to obtain pressure measurements at 20-ms intervals by oscillometric cuff signal pattern recognition. Derivation of noninvasive pressure measurements is based on a T tube aorta and straight tube brachial artery, and assumes that the systolic phase of the suprasystolic cuff signal and the diastolic phase of the subdiastolic cuff signal most closely approximate systolic and diastolic aortic pressures, respectively. Arterial pressures obtained by this method were compared with simultaneous invasive measurements from the thoracic aorta in 36 patients. Good agreement was observed between noninvasive and invasive methods for systolic (146 ± 4 vs 145 ± 5 mm Hg), diastolic (80 ± 2 vs 77 ± 2 mm Hg), and mean (100 ± 3 vs 100 ± 3 mm Hg) arterial pressures, and correlation coefficients were r = 0.94, 0.91, and 0.95, respectively. To assess the validity of measurements of the rate of pressure change, oscillometric cuff signals from a subgroup of 14 patients were analyzed in detail for the peak positive pressure derivative (dP/dtMax), peak negative pressure derivative (dP/dtMin), and time interval between peak positive and peak negative pressure derivatives [tpp]. Results (mean ± SEM) were:

Empty CelldP/dtMaxdP/dtMintpp
Noninvasive600 ± 41−466 ± 360.25 ± 0.01
Invasive508 ± 37−377 ± 270.25 ± 0.01
r (linear regression)0.870.680.85
The incorporation of measurements of the rate of pressure change into a physical model of the brachial artery was used to derive vascular compliance. A significant correlation was observed between vascular compliance derived from the oscillometric signal and determinations by either thermodilution or Fick methods and noninvasive pressures (n = 20, r = 0.83, p <0.001). Day-to-day variability for blood pressure and vascular compliance derived by the noninvasive method did not differ by >4%, representing a reproducible measure of vascular structure and function. We conclude that the measurement of absolute pressure and rate of pressure change show good correlation with catheter data and that vascular compliance can be reliably assessed by this new method. The technology should provide a valuable noninvasive tool for the assessment of both cardiac function and vascular properties.

Section snippets

Study Group

The Study Group Consisted of 56 Patients Undergoing Diagnostic Evaluation For Cardiovascular Disease at Ucsd Medical Center. the First Group Consisted of 36 Patients Undergoing only Left-Sided Cardiac Catheterization Who Were Used To Validate the accuracy of Systolic, Diastolic, and Mean arterial Pressure (map) Measurements. Detailed analysis Was also Performed in 14 of these Patients To Establish Measurement accuracy For the Rate of Pressure Change Derived From the Oscillometric Signal. an

Results

To assess the ability of this new method to provide accurate measurements, simultaneous pressures were obtained noninvasively and by intraarterial cannulation. Table 1 lists values for systolic, diastolic, pulse, and MAPs for both methods. A strong correlation was observed for invasive and noninvasive systolic (r = 0.94), diastolic (r = 0.91), and MAP (r = 0.95). Linear regression analysis of noninvasively and invasively derived pressures was performed for both systolic and diastolic pressures

Discussion

Examination of not only the level of arterial pressure but also the rate of pressure change are important in evaluating cardiovascular function.[12] Until recently, direct catheterization was the only technique used to evaluate pressure dynamics. However, invasive measurements may be time-consuming and expensive, are associated with potential patient risk and discomfort, and are thereby of limited use for many clinical applications. This study describes a new noninvasive technology that

Acknowledgements

We would like to thank the University of California, San Diego Medical Center catheterization laboratory staff for assistance in data collection during the catheterization procedures. In addition, we acknowledge the staff at the Hypertension Research Center, San Diego Veterans Administration Hospital, and Pulse Metric, Inc.

This study was supported by Pulse Metric, Incorporated, San Diego, California.

References (26)

  • GM Drzewiecki et al.

    Arterial tonometry: review and analysis

    J Biomech

    (1983)
  • MF O’Rourke

    The arterial pulse in health and disease

    Am Heart J

    (1991)
  • RD Latham et al.

    Regional wave travel and reflections along the human aorta: a study with six simultaneous micromanomeric pressures

    Circulation

    (1985)
  • MF O’Rourke

    Pulsatile arterial hemodynamics in hypertension

    Aust N Z J Med

    (1976)
  • MJ Kern et al.

    Interpretation of cardiac pathophysiology from pressure waveform analysis: III. Intraventricular pressure gradients

    Cathet Cardiovasc Diagn

    (1991)
  • MJ Kern et al.

    Interpretation of cardiac pathophysiology from pressure waveform analysis: I. The stenotic aortic valve

    Cathet Cardiovasc Diagn

    (1990)
  • GE McVeigh et al.

    Reduced vascular compliance as a marker for essential hypertension

    Am J Hypertens

    (1991)
  • RM Goldwyn et al.

    Arterial pressure contour analysis via a mathematical model for the clinical qualification of human vascular properties

    IEEE Trans Biomed Eng

    (1967)
  • TB Watt et al.

    Arterial pressure contour analysis for estimating human vascular properties

    J Appl Physiol

    (1976)
  • Z Liu et al.

    Estimation of total arterial compliance: an improved method and evaluation of current methods

    Am J Phisiol

    (1986)
  • GM London et al.

    Brachial artery diameter changes associated with cardiopulmonary baroreflex activation in humans

    Am J Physiol

    (1990)
  • Levenson et al.

    Pulsed Doppler: determination of diameter, blood flow velocity, and volumetric flow of brachial artery in man

    Cardiovasc Res

    (1981)
  • JW Hurst et al.

    Examination of the Arteries and their Pulsation

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