Continuous Blood Pressure Monitoring Methods
Saturday, Dec 22 2007
Unfortunately, both auscultatory and oscillometric methods of blood pressure assessment are intermittent measures in that a single blood pressure determination can take almost an entire minute to obtain.
Additionally, a brief rest period is recommended between measures of blood pressure that require use of an occluding cuff to allow circulation in the limb to return to normal. Therefore, if an investigator is interested in measuring immediate and short-lived alterations in blood pressure, intermittent blood pressure measures would not be a good choice. Two noninvasive approaches for measuring blood pressure continuously have been developed, pulse transit time (or pulse wave velocity) and the vascular unloading method.
Pulse Transit Time
Pulse transit time reflects the time it takes the pulse wave to travel from the heart to a site in the peripheral circulation, typically the finger or earlobe. It is commonly assessed by measuring the duration of time (in ms) between the initiation of the cardiac contraction from the electrocardiogram (ECG) and the arrival of the pulse wave at the peripheral site, typically measured using photoplethysmography.
Presumably, as arterial pressure increases, the pulse wave travels more quickly to the peripheral site (lower pulse transit time); conversely, as arterial pressure declines, pulse transit time lengthens (Gribbin, Steptoe, and Sleight, 1976). Although studies comparing changes in pulse transit time with blood pressure change have yielded significant inverse correlations, these correlations have been more commonly observed between measures of pulse transit time and SBP than between pulse transit time and DBP (Newlin, 1981; Obrist et al., 1979).
Furthermore, researchers who employed measures of pulse transit time have disagreed as to whether the continuous temporal parameter actually represented an index of blood pressure, as there was considerable evidence suggesting it was more strongly linked to beta-adrenergic cardiac activity than to blood pressure (Newlin, 1981; Obrist et al., 1979). Because of these equivocal findings linking changes in pulse transit time to alterations in blood pressure, this method has not been recommended as a surrogate measure of blood pressure (Shapiro et al., 1996).
Semenchuk, E. M., and Larkin, K. T.
Published with assistance from the foundation established in memory of Amasa Stone Mather of the Class of 1907, Yale College.
- Abel, J. A., and Larkin, K. T. (1991). Assessment of cardiovascular reactivity across laboratory and natural settings. Journal of Psychosomatic Research, 35, 365 - 373.
- Achmon, J., Granek, M., Golomb, M., and Hart, J. (1989). Behavioral treatment of essential hypertension: A comparison between cognitive therapy and biofeedback of heart rate. Psychosomatic Medicine, 51, 152 - 164.
- Agras, W. S., Horne, M., and Taylor, C. B. (1982). Expectation and the blood-pressure-lowering effects of relaxation. Psychosomatic Medicine, 44, 389 - 395.
- Agras, W. S., Taylor, C. B., Kraemer, H. C., Southam, M. A., and Schneider, J. A. (1987). Relaxation training for essential hypertension at the worksite: II. The poorly controlled hypertensive. Psychosomatic Medicine, 49, 264 - 273.
- Aivazyan, T. A., Zaitsev, V. P., Khramelashvili, V. V., Golenov, E. V., and Kichkin, V. I. (1988). Psychophysiological interrelations and reactivity characteristics in hypertensives. Health Psychology, 7, 137 - 144.
- al'Absi, M., and Wittmers, L. E. (2003). Enhanced adrenocortical responses to stress in hypertension-prone men and women. Annals of Behavioral Medicine, 25, 52 - 33.
- Albright, C. L., Winkleby, M. A., Ragland, D. R., Fisher, J., and Syme, S. L. (1992). Job strain and prevalence of hypertension in a biracial population of urban bus drivers. American Journal of Public Health, 82, 984 - 989.
- Davidyan, A. (1989). Emotional factors in essential hypertension. Psychosomatic Medicine, 55, 505 - 517.
- Alfredsson, L., Davidyan, A., Fransson, E., de Faire, U., Hallqvist, J., Knutsson, A., et al. (2002). Job strain and major risk factors for coronary heart disease among employed males and females in a Swedish study on work, lipids, and fibrinogen. Scandinavian Journal of Work, Environment and Health, 28, 238 - 248.
Last revised: by Dr. Loren Hooper, M.D.
Provided by Armina Hypertension Association
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