Abstract
Simultaneous measurements of aortic and radial artery pressures are reviewed, and a model of the cardiovascular system is presented. The model is based on resonant networks for the aorta and axillo-brachial-radial arterial system. The model chosen is a simple one, in order to make interpretation of the observed relationships clear. Despite its simplicity, the model produces realistic aortic and radial artery pressure waveforms. It demonstrates that the resonant properties of the arterial wall significantly alter the pressure waveform as it is propagated from the aorta to the radial artery. Although the mean and end-diastolic radial pressures are usually accurate estimates of the corresponding aortic pressures, the systolic pressure at the radial artery is often much higher than that of the aorta due to overshoot caused by the resonant behavior of the radial artery. The radial artery dicrotic notch is predominantly dependent on the axillo-brachial-radial arterial wall properties, rather than on the aortic valve or peripheral resistance. Hence the use of the radial artery dicrotic notch as an estimate of end systole is unreliable. The rate of systolic upstroke, dP/dt, of the radial artery waveform is a function of many factors, making it difficult to interpret. The radial artery waveform usually provides accurate estimates for mean and diastolic aortic pressures; for all other measurements it is an inadequate substitute for the aortic pressure waveform. In the presence of low forearm peripheral resistance the mean radial artery pressure may significantly underestimate the mean aortic pressure, as explained by a voltage divider model.
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Slogoff S, Keats AS, Arlund C. On the safety of radial artery cannulation. Anesthesiology 1983;59:42–47
Prys-Roberts C. Invasive monitoring of the circulation. In: Saidman LJ, Smith NT, eds. Monitoring in anesthesia. 2nd ed. Boston: Butterworth, 1984:82–83
Starmer CF, McHale PA, Cobb FR, Greenfield JC, Jr. Evaluation of several methods for computing stroke volume from central aortic pressure. Circ Res 1973;23:139–148
Remington JW. Volume quantification of the aortic pressure pulse. Fed Proc 1952;2:750–761
Wesseling KH, Smith NT, Nichols WW, et al. Beat to beat cardiac output from the arterial pressure pulse contour. In: Spierdijk J, Feldman SA, Cliffe P, eds. Measurement in anaesthesia. Baltimore: Williams & Wilkins, 1973: 150–164
Sarnoff SJ, Braunwald E, Welch GH, et al. Hemodynamic determinants of oxygen consumption of the heart with special reference to tension time index. Am J Physiol 1958;192:148–156
Buckberg GD, Towers B, Paglia DE, et al. Subendocardial ischemia after cardiopulmonary bypass. J Thorac Cardiovasc Surg 1972;64:669–680
Hamilton WF. The patterns of the arterial pressure pulse. Am J Physiol 1944;141:235–241
Defares JG, Van Der Wall HJ. A method for the determination of systemic arterial compliance in man. Acta Physiol Pharmacol Neerl 1969;15:329–343
Gerber MJ, Carp B, Hines R, Barash PG. Arterial waveforms and systemic vascular resistance. Is there a correlation? Anesthesiology 1985;63:A70
Reitan JA, Martucci RW, Levine NA. A computer evaluation of the ratio of the diastolic pressure-time index to the time-tension index from three arterial sites in dogs. J Clin Monit 1986;2:95–99
Wesseling KH, de Wit B, Weber JAP, Smith NT. A simple device for the continuous measurement of cardiac output. Advances in Cardiovascular Physics 1983;5(2):16–53
Snyder MF, Rideout VC, Hillestad RJ. Computer modelling of the human arterial tree. J Biomech 1968;1:341–353
Noordergraaf A. Development of an analog computer for the human systemic circulatory system. In: Noordergraaf A, Jager GN, Westerhof N, eds. Circulatory analog computers. Amsterdam: North-Holland, 1963:29–44
Suga H, Sagawa K, Shoukas AA. Load independence of the instantaneous pressure-volume ratio of the canine left ventricle and the effects of epinephrine and heart rate on the ratio. Circ Res 1973;32:314–322
Bellhouse BJ. The fluid mechanics of heart valves. In: Bergel DH, ed. Cardiovascular fluid dynamics. London: Academic Press, 1972:261–285
Wesseling KH, Weber H, de Wit B. Estimated five component viscoelastic model parameters for human arterial walls. J Biomech 1973;6:13–24
Wesseling KH, Weber H, de Wit B. Variable heart rate electronic simulator for some haemodynamic signals. Med Biol Eng 1973;11:214–216
Wesseling KH, de Wit B, Beneken JEW. Arterial haemodynamic parameters derived from noninvasively recorded pulsewaves, using parameter estimation. Med Biol Eng 1973;11:724–731
Gardner RM, Warner HR, Toronton AF, Gaisford WD. Catheter-flush system for continuous monitoring of central arterial pulse waveform. J Appl Physiol 1970;29:911–913
Gardner RM. Direct blood pressure measurement: dynamic response requirements. Anesthesiology 1981;54: 227–236
Stern DH, Gerson JI, Allen FB, Parker FB. Can we trust the direct radial artery pressure immediately following cardiopulmonary bypass? Anesthesiology 1985;62:557–561
Frank O. Die Gundform des Arteriellen Pulses; le Abhandlung: Mathematische Analyse. Z Biol 1899;37: 483–526
Frank O. Der Puls in den Arterien. Z Biol 1905;46:441–553
Warner HR. A study of the mechanism of pressure wave distortion by arterial walls using an electrical analog. Circ Res 1957;5:79–84
O’Rouke MF. Arterial function in health and disease. Edinburgh: Churchill Livingstone, 1982:137–144
Murgo JP, Westerhof N. Arterial reflections and pressure waveforms in humans. In: Yin FCP, ed. Ventricular/ vascular coupling. New York: Springer-Verlag, 1986: 140–158
Remington JW, Wood EH. Formation of peripheral pulse contour in man. J Appl Physiol 1956;9:433–442
Kroeker EJ, Wood EH. Beat-to-beat alterations in relationship of simultaneously recorded central and peripheral arterial pressure pulses during Valsalva maneuver and prolonged expiration in man. J Appl Physiol 1956;8:483–494
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The authors thank Patricia Dorsa for her secretarial assistance in the preparation of this manuscript.
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Schwid, H.A., Taylor, L.A. & Smith, N.T. Computer Model Analysis of the Radial Artery Pressure Waveform. J Clin Monitor Comput 3, 220–228 (1987). https://doi.org/10.1007/BF03337375
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DOI: https://doi.org/10.1007/BF03337375