The Effect of Blood Pressure Alteration on the Pulse Wave Velocity

Abstract

Determinations of the pulse wave velocity (PWV) in living subjects have shown that higher values are found with increasing age (Rahier, 1961;Simonson and Nakagawa, 1960) and in the presence of hypertension, with or without presumed atherosclerosis, but more so in the former case (Miasnikov, 1960). Woolam et al. (1962) have also shown higher values in diabetics with presumed atherosclerosis, compared with normal subjects.Comparison of PWV values obtained by different workers is difficult because of the variable techniques employed and different criteria used in estimating the length of the vessel over which the recordings were made; in addition not all workers have used the same vessels for their measurements, or the same events in the cardiac cycle for timing purposes. It may be assumed further that recordings are usually carried out with the patient in the supine position but this is not always specified.Attention to these points is essential in considering what importance to attach to differences in figures given by various authors in reported PWV measurements. It is noted for example that the "normal" values quoted by Miasnikov are lower than those of Rahier's series by almost two metres. per second for subjects in their third decade. The values of PWV measured in peripheral vessels are higher than corresponding measurements in the aorta. This is consistent with the Moens-Korteweg equation (Moens, 1878; Korteweg, 1878), which is as follows:PWV=g where E is the transverse elasticity coefficient, h is the thickness of vessel wall, r is the radius of the vessel and p' is the density of fluid. In terms of this equation, and other values being constant, PWV is inversely proportional to the square root of the vessel radius.With the present recording methods accurate measurement of the very small delays between the arrival of the pulse wave at different points along a short vessel is not easy, even if the complicating effects of wave reflections from arterial branchings are ignored (McDonald, 1960).Hitherto little or no documentation concernilig the effect of induced blood pressure alterations in the living subject on the PWV has appeared although it is generally agreed that the PWV is directlyproportional to the level of blood pressure, albeit in terms of a non-linear relation: the experimental studies on living dogs and isolated aorta from these animals by Hamilton, Remington, and Dow (1945) support this view.The above considerations prompted this study into the magnitude of the contribution to the PWV made by the blood pressure in living subjects.

Analysis of vascular function using the cardio–ankle vascular index (CAVI)

“…Blood pressure will decrease as a result. In addition, brachial-ankle pulse wave velocity will thus decrease because pulse wave velocity depends on blood pressure at the time of the measurement, as reported by Nye et al [2][3][4]6 Under these conditions, a decrease in CAVI might be due to the relaxation of smooth muscle cells induced by general anesthesia itself and by administration of propofol. The report by Kim described two important features of CAVI: (1) CAVI expression changes over a short period of time, depending on the circulatory condition; and (2) CAVI expression reflects the state of smooth muscle cell contraction.…”

Cuff-Less and Continuous Blood Pressure Monitoring: A Methodological Review

“…The underlying principle of these devices is based on the relation of the time it takes for a volume of blood (in the form of a pulse) to travel from the heart to a peripheral organ, which could be in the form of pulse transit time (PTT) or pulse arrival time (PAT) [22][23][24]. Algorithms and mathematical models have been proposed and developed to optimize the regression process and calibration of the traveling/delay time ("Time Delay") and BP [25][26][27].…”

Acute Decrease of Cardio-Ankle Vascular Index with the Administration of Beraprost Sodium

“…2, A, B, C, D, the differences in arterial stiffness parameters (Δ) between before and after BPS administration in each hour were calculated Correlations between ΔbaPWV and ΔBlood pressures during 3 hour after Beraprost sodium administration however, it was reported that baPWV includes two components: blood pressure and arterial stiffness 12) . On the other hand, CAVI is independent of blood pressure 11) , so sensitivity in the acute phase for smooth muscle contraction was induced by BPS administration in a small group of middle-aged healthy subjects.…”

“…Pulse wave velocity (PWV) has been proposed and is used currently [3][4][5] , and many valuable data have been reported [6][7][8][9] ; however, a problem of PWV in clinical use is that PWV itself essentially depends on blood pressure. Hasegawa and coworkers 10) identified PWV variability depending on diastolic pressure from studies using the human aorta, and developed a monograph compensating for PWV by diastolic pressure; however, PWV itself is an indirect method reflecting arterial wall stiffness at the measuring time 11,12) . Recently, the cardio-ankle vascular index (CAVI) was proposed, which essentially represents the stiffness parameter of the aorta, femoral artery and tibial artery.…”