Pulse Wave Velocity and Blood Pressure Change: Calibration and Applications

Abstract

An adaptation of the technique for measuring pulse wave velocity is described in which the interval between the R wave of the ECG and the radial pressure pulse is monitored. The resulting transit time (TT) is suitable for use as an indirect measure of blood pressure change. The reliability of the measure was assessed in 5 subjects who volunteered for arterial cannulation on 2 occasions. Simultaneous recordings of intra‐arterial pressure and TT were taken during a variety of maneouvres, including mental arithmetic, isometric exercise, and amyl nitrite inhalation. The dependence of changes in TT on arterial pressure was confirmed for all procedures except amyl nitrite inhalation. Linear correlations between TT and mean arterial pressure were high, varying between −.913 and −.98. The regression coefficients were reproducible and similar in all individuals. The reasons for the anomalous amyl nitrite response are discussed, together with the limits of application of the measure.

Pulse transit time: Relationship to blood pressure

“…Both DBP and PTT are subject to several influences that can be independent, thus making the procedure of using PTT to index variations of DBP of dubious value unless these influences are known (see Obrist et al, Note I for a further discussion of this issue). The results of this study are similar to those reported by Gribbin et al (1976) and Steptoe et al (1976). Because the Steptoe et al study is more similar in procedural matters, some comparison of results is justified.…”

“…It is difficult to judge, even in light of the pronounced relationship they observed how sensitive transit time will be to natural variations in arterial distensibility and pressure. In the study by Steptoe et al (1976), as in the present study, the PTT was triggered from the R wave of the EKG, so the Steptoe data sheds no light on this issue.…”

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

“…Cold Pressure Placement of ice wrapped in wet cloth on subject's forehead for 2 min. Hand in 4 • C water for 1 min [102,103] Mental Arithmetic Counting backwards from 500 in intervals of 7, Continuous addition of 3 digit numbers for 2 min [104] Relaxation Slow breathing/Meditative music [105,106] Amyl Nitrate Inhalation of vasodilator [107] Anesthesia Dental anesthesia [84,108] Isometric Exercise Raising legs/arms against pressure [109] Sustained Handgrip Clenching one's fist forcefully [110,111] Technologies 2017, 5, 21 10 of 19 inaccuracy of existing algorithms using PAT in tracking Low-Frequency (LF) variations in BP was one of the main reasons for inaccurate results [90,113]. In order to improve the accuracy, they introduced a factor termed "photoplethysmogram intensity ratio" (PIR), which could be determined by the ratio of the peak (Ip) and the foot (If) PPG values (Figure 3c).…”

Arterial pulse transit time and ECG-initiated transit time: The form of the conditioned responses

“…As a function of changes in the duration of the preejection period component, ECG-TT has been shown to reflect changes in beta-adrenergic influences on the myocardium (Keller & Rodbard, 1971;Obrist, Light, McCubbin, Hutcheson, & Hoffer, 1979). ECG-TT has also been shown to correlate highly with systolic blood pressure (Allen, Schneider, Davidson, Winchester, & Barr-Taylor, 1981) and with mean arterial pressure (Steptoe, Smulyan, & Gribbin, 1976). During the presentation of the CS+ in the experiments described here, the changes in ECG-TT appear to reflect an initial decrease in beta-adrenergic influence on the myocardium and in systolic blood pressure, followed by an increase in these aspects of cardiovascular activity prior to UCS onset.…”