Wave intensity analysis from the common carotid artery: a new noninvasive index of cerebral vasomotor tone

The study of wave propagation at different points in the arterial circulation may provide useful information regarding ventriculoarterial interactions. We describe a number of hemodynamic parameters in the carotid, brachial, and radial arteries of normal subjects by using noninvasive techniques and wave-intensity analysis (WIA). Twenty-one normal adult subjects (14 men and 7 women, mean age 44 ± 6 yr) underwent applanation tonometry and pulsed-wave Doppler studies of the right common carotid, brachial, and radial arteries. After ensemble averaging of the pressure and flow-velocity data, local hydraulic work was determined and a pressure-flow velocity loop was used to determine local wave speed. WIA was then applied to determine the magnitude, timings, and energies of individual waves. At all sites, forward-traveling (S) and backward-traveling (R) compression waves were observed in early systole. In mid- and late systole, forward-traveling expansion waves (X and D) were also seen. Wave speed was significantly higher in the brachial (6.97 ± 0.58 m/s) and radial (6.78 ± 0.62 m/s) arteries compared with the carotid artery (5.40 ± 0.34 m/s; P < 0.05). S-wave energy was greatest in the brachial artery (993.5 ± 87.8 mJ/m2), but R-wave energy was greatest in the radial artery (176.9 ± 19.9 mJ/m2). X-wave energy was significantly higher in the brachial and radial arteries (176.4 ± 32.7 and 163.2 ± 30.5 mJ/m2, respectively) compared with the carotid artery (41.0 ± 9.4 mJ/m2; P < 0.001). WIA illustrates important differences in wave patterns between peripheral arteries and may provide a method for understanding ventriculo-arterial interactions in the time domain.

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Noninvasive assessment of the common carotid artery hemodynamics with increasing exercise work rate using wave intensity analysis

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00667.2017 ◽

2018 ◽

Vol 315 (2) ◽

pp. H233-H241 ◽

Cited By ~ 3

Author(s):

N. Pomella ◽

E. N. Wilhelm ◽

C. Kolyva ◽

J. González-Alonso ◽

M. Rakobowchuk ◽

...

Keyword(s):

Blood Flow ◽

Carotid Artery ◽

Common Carotid Artery ◽

Wave Speed ◽

Work Rate ◽

Incremental Exercise ◽

Wave Intensity ◽

Ventricular Contractility ◽

Flow Deceleration ◽

The Common

Noninvasively determined local wave speed ( c) and wave intensity (WI) parameters provide insights into arterial stiffness and cardiac-vascular interactions in response to physiological perturbations. However, the effects of incremental exercise and subsequent recovery on c and WI have not been fully established. We examined the changes in c and WI parameters in the common carotid artery (CCA) during exercise and recovery in eight young, healthy male athletes. Ultrasound measurements of CCA diameter and blood flow velocity were acquired at rest, during five stages of incremental exercise (up to 70% maximum work rate), and throughout 1 h of recovery, and noninvasive WI analysis [diameter-velocity ( DU) approach] was performed. During exercise, c increased (+136%), showing increased stiffness with work rate. All peak and area of forward compression, backward compression, and forward expansion waves increased during exercise (+452%, +700%, and +900%, respectively). However, WI reflection indexes and CCA resistance did not significantly change from rest to exercise. Furthermore, wave speed and the magnitude of all waves returned to baseline within 5 min of recovery, suggesting that the effects of exercise in the investigated parameters of young, healthy individuals were transient. In conclusion, incremental exercise was associated with an increase in local CCA stiffness and increases in all wave parameters, indicative of enhanced ventricular contractility and improved late-systolic blood flow deceleration. NEW & NOTEWORTHY We examined hemodynamics of the common carotid artery using noninvasive application of wave intensity analysis during exercise and recovery. The hemodynamic adjustments to exercise were associated with increases in local common carotid artery stiffness and all waves’ parameters, with the latter indicating enhanced ventricular contractility and improved late systolic blood flow deceleration.

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P8.12 CAROTID ARTERY WAVE INTENSITY ANALYSIS IN HEALTHY HUMANS DURING EXERCISE

Artery Research ◽

10.1016/j.artres.2015.10.334 ◽

2015 ◽

Vol 12 (C) ◽

pp. 37

Author(s):

Nicola Pomella* ◽

Eurico Wilhelm Neto ◽

Christina Kolyva ◽

Mark Rakobowchuk ◽

Jose Gonzalez-Alonso ◽

...

Keyword(s):

Carotid Artery ◽

Wave Intensity ◽

Intensity Analysis ◽

Wave Intensity Analysis ◽

Healthy Humans

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Carotid artery wave intensity in mid- to late-life predicts cognitive decline: the Whitehall II study

European Heart Journal ◽

10.1093/eurheartj/ehz189 ◽

2019 ◽

Vol 40 (28) ◽

pp. 2300-2309 ◽

Cited By ~ 18

Author(s):

Scott T Chiesa ◽

Stefano Masi ◽

Martin J Shipley ◽

Elizabeth A Ellins ◽

Alan G Fraser ◽

...

Keyword(s):

Risk Factors ◽

Cognitive Function ◽

Carotid Artery ◽

Cognitive Decline ◽

Common Carotid Artery ◽

Late Life ◽

Wave Intensity ◽

Cognitive Score ◽

The Common

Abstract Aims Excessive arterial pulsatility may contribute to cognitive decline and risk of dementia via damage to the fragile cerebral microcirculation. We hypothesized that the intensity of downstream-travelling pulsatile waves measured by wave intensity analysis in the common carotid artery during mid- to late-life would be associated with subsequent cognitive decline. Methods and results Duplex Doppler ultrasound was used to calculate peak forward-travelling compression wave intensity (FCWI) within the common carotid artery in 3191 individuals [mean ± standard deviation (SD), age = 61 ± 6 years; 75% male] assessed as part of the Whitehall II study in 2003–05. Serial measures of cognitive function were taken between 2002–04 and 2015–16. The relationship between FCWI and cognitive decline was adjusted for sociodemographic variables, genetic and health-related risk factors, and health behaviours. Mean (SD) 10-year change in standardized global cognitive score was -0.39 (0.18). Higher FCWI at baseline was associated with accelerated cognitive decline during follow-up [difference in 10-year change of global cognitive score per 1 SD higher FCWI = −0.02 (95% confidence interval −0.04 to −0.00); P = 0.03]. This association was largely driven by cognitive changes in individuals with the highest FCWI [Q4 vs. Q1–Q3 = −0.05 (−0.09 to −0.01), P = 0.01], equivalent to an age effect of 1.9 years. Compared to other participants, this group was ∼50% more likely to exhibit cognitive decline (defined as the top 15% most rapid reductions in cognitive function during follow-up) even after adjustments for multiple potential confounding factors [odds ratio 1.49 (1.17–1.88)]. Conclusion Elevated carotid artery wave intensity in mid- to late-life predicts faster cognitive decline in long-term follow-up independent of other cardiovascular risk factors.

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