Carotid Artery Pulse Wave Research Articles

Chronic SIRT1 supplementation in diabetic mice improves endothelial function by suppressing oxidative stress.

Enhancing SIRT1 activity exerts beneficial cardiovascular effects. In diabetes, plasma SIRT1 levels are reduced. We aimed to investigate the therapeutic potential of chronic recombinant murine SIRT1 (rmSIRT1) supplementation to alleviate endothelial and vascular dysfunction in diabetic mice (db/db). Left internal mammary arteries obtained from patients undergoing coronary artery bypass grafting with or without a diagnosis of diabetes were assayed for SIRT1 protein levels. Twelve-week-old male db/db mice and db/+ controls were treated with vehicle or rmSIRT1 intraperitoneally for 4 weeks, after which carotid artery pulse wave velocity (PWV) and energy expenditure/activity were assessed by ultrasound and metabolic cages, respectively. Aorta, carotid, and mesenteric arteries were isolated to determine endothelial and vascular function using the myograph system.Arteries obtained from diabetic patients had significantly lower levels of SIRT1 relative to non-diabetics. In line, aortic SIRT1 levels were reduced in db/db mice compared to db/+ mice, while rmSIRT1 supplementation restored SIRT1 levels. Mice receiving rmSIRT1 supplementation displayed increased physical activity and improved vascular compliance as reflected by reduced PWV and attenuated collagen deposition. Aorta of rmSIRT1-treated mice exhibited increased endothelial nitric oxide (eNOS) activity, while endothelium-dependent contractions of their carotid arteries were significantly decreased, with mesenteric resistance arteries showing preserved hyperpolarization. Ex vivo incubation with reactive oxygen species (ROS) scavenger Tiron and NADPH oxidase inhibitor apocynin revealed that rmSIRT1 leads to preserved vascular function by suppressing NADPH oxidase (NOX)-related ROS synthesis. Chronic rmSIRT1 treatment resulted in reduced expression of both NOX1 and NOX4, in line with a reduction in aortic protein carbonylation and plasma nitrotyrosine levels. In diabetic conditions, arterial SIRT1 levels are significantly reduced. Chronic rmSIRT1 supplementation improves endothelial function and vascular compliance by enhancing eNOS activity and suppressing NOX-related oxidative stress. Thus, SIRT1 supplementation may represent novel therapeutic strategy to prevent diabetic vascular disease.

Evaluation of the carotid artery using wavelet-based analysis of the pulse wave signal

<p>The use of pulse wave analysis may assist cardiologists in diagnosing patients with vascular diseases. However, it is not common in clinical practice to interpret and analyze pulse wave data and utilize them to detect the abnormalities of the signal. This paper presents a novel approach to the clinical application of pulse waveform analysis using the wavelet technique by decomposing the normal and pathology signal into many levels. The discrete wavelet transform (DWT) decomposes the carotid arterial pulse wave (CAPW) signal, and the continuous wavelet transform (CWT) creates images of the decomposed signal. The wavelet analysis technique in this work aims to strengthen the medical benefits of the pulse wave. The obtained results show a clear difference between the signal and the images of the arterial pathologies in comparison with normal ones. The certain distinct that were achieved are promising but further improvement may be required in the future.</p>

Photometric recorder of the carotid artery pulse wave with a system for stabilizing the clamping force

Preventive monitoring, which increases the possibility of diagnosing and curing a disease at an early stage, is interesting and relevant in medical diagnostics. Recently, both minimally invasive and non-invasive diagnostic techniques have become widespread. They include the areas of cardiographic, encephalographic and myographic analyzers designed to study the state of the heart, the brain and striated muscles. The study of the functioning of the smooth muscles of the gastrointestinal tract is carried out using gastro-enterography methods. To obtain an integral assessment of the effectiveness of the circulatory system, the plethysmography method can be successfully applied, which allows modeling vascular tone and blood flow using models of hydrodynamics and the theory of elasticity. The present article analyzes the range of static (or dynamic) informative hemo-parameters that allow diagnosing at the initial stage arterial hypertension, aortic insufficiency or stenosis, atherosclerosis, diabetes mellitus and some other diseases. The photometric reflex absorption in the infrared range, followed by an assessment of blood flow in the aortas and arteries with recording of the shape of pulse waves were used as methods in our research work. The result of the work is a method and a system of computer control of the rod current acting on biological tissues (using the Bluetooth protocol, LabView environment, virtual digital filters and biomedical data archives) that allows non-invasively recording of the parameters of the carotid artery pulse wave.

Masked hypertension risk as condition of arterial stiffness in cardiovascular risk patients: a pilot single-stage screening observational study

Background. Masked arterial hypertension (MAH) is associated with asymptomatic injury of both heart and kidneys. Links between MAH and arterial stiffness are unclear, with debates ongoing on their mutual causative relation. Research into the arterial stiffness contribution to MAH development is a perspective area of cardiology.Objectives. The MAH risk assessment as a condition of arterial stiffness in patients at cardiovascular risk (CVR) without a verified cardiovascular disease (CVD).Methods. A single-stage screening observational study included a total of 92 CVR patients without a verified cardiovascular disease. The trial conducted general clinical examination, daily blood pressure monitoring (DBPM), volumetric sphygmoplethysmography with reading cardio-ankle vascular index (CAVI1), aortic and carotid artery pulse wave velocity (PWV), carotid-femoral PWV (CFV) and augmentation index.Results. Patients were assigned in two cohorts by MAH presence, the primary MAH (58; 63.0%) and normal BP in DBPM (34; 37.0% patients) cohorts. The cohorts did not discord by age, major CVR factors, comorbidity or clinical profile. Men prevailed over women in the MAH cohort (p = 0.028). The cohorts had similar CFV, aortic PWV and augmentation index. Carotid PWV was higher in the MAH cohort both in mean values and elevation rate (p = 0.002 and p = 0.035, respectively). OR and HR were 3.29 and 2.35 (95% CI for OR 1.08–10.49, HR 1.05– 6.02), respectively. MAH was associated with increased CAVI1 for mean values and CAVI1 > 8 incidence rate (p = 0.010 and 0.049, respectively); OR 3.29 (95% CI 1.00–11.41), HR 2.46 (95% CI 1.00–7.10). Correlation analysis revealed a moderate direct dependence between the MAH presence and elevation rate of C-PWV (Q = 0.53) and CAVI1 > 8 (Q = 0.53).Conclusion. The risk of MAH development in CVR patients is both gender and arterial stiffness-dependent. MAH development is associated with increased CAVI1 and carotid PWV.

Ultrasonic evaluation of carotid artery elasticity in People Living with HIV

Objective To evaluate the quantitative parameters of carotid elasticity in healthy people and People Living With HIV(PLWH) by ultrasonic vascular elasticity quantitative technique, and to explore the feasibility of this technique in non-invasive evaluation of preclinical arterial elasticity in patients with PLWH atherosclerosis. Methods Subjects with carotid intima-media thickness (IMT) < 1.5mm were divided into three groups: healthy control group (n = 60), HIV baseline group (n = 291) and HAART group (n = 67) with HIV infection who had received highly active antiretroviral therapy ((HAART) for more than 5 years. Quantitative analysis of ultrasonic vascular elasticity was performed in all subjects, and the software automatically quantified carotid artery IMT, artery internal diameter, motion amplitude, vascular hardness coefficient and carotid artery pulse wave velocity,( caPWV), and thean to compare the ultrasonic parameters and blood lipids of each group. In HAART group, the correlation between brachial-ankle pulse wave velocity (baPWV) measured by traditional pressure wave method and caPWV was analyzed. Results Total Cholesterol (TC), triglyceride (TG) and high-density lipoprotein cholesterol (HDL-C) in HAART group were higher than those in baseline group (P < 0.017). Hardness coefficient and caPWV of bilateral carotid arteries in HAART group were higher than those in baseline group (P < 0.017), but the movement amplitude was lower than that in baseline group. In the healthy group, there was no significant difference between the left and right carotid arteries (P > 0.05). In HAART group, baPWV was linearly correlated with caPWV, with the left side correlation coefficient of 0.60 and the right side correlation coefficient of 0.57. Conclusion There is a decrease in preclinical elasticity of carotid artery in patients with PLWH who take antiviral therapy for a long time, and ultrasound vascular elasticity quantitative technique is helpful to identify this change.

Arterial Stiffness Assessment by Shear Wave Elastography and Ultrafast Pulse Wave Imaging: Comparison with Reference Techniques in Normotensives and Hypertensives

Shear wave elastography and ultrafast imaging of the carotid artery pulse wave were performed in 27 normotensive participants and 29 age- and sex-matched patients with essential hypertension, and compared with reference techniques: carotid–femoral pulse wave velocity (cfPWV) determined via arterial tonometry and carotid stiffness (carPWV) determined via echotracking. Shear wave speed in the carotid anterior (a–SWS) and posterior (p-SWS) walls were assessed throughout the cardiac cycle. Ultrafast PWV was measured in early systole (ufPWV–FW) and in end-systole (dicrotic notch, ufPWV-DN). Shear wave speed in the carotid anterior appeared to be the best candidate to evaluate arterial stiffness from ultrafast imaging. In univariate analysis, a-SWS was associated with carPWV (r = 0.56, p = 0.003) and carotid-to-femoral PWV (r = 0.66, p < 0.001). In multivariate analysis, a–SWS was independently associated with age (R² = 0.14, p = 0.02) and blood pressure (R² = 0.21, p = 0.004). Moreover, a–SWS increased with blood pressure throughout the cardiac cycle and did not differ between normotensive participants and patients with essential hypertension when compared at similar blood pressures.

Abstract 729: Ultrasound Ultrafast Imaging of the Carotid Artery Pulse Wave Velocity: is the Surrogate of Regional Artery Stiffness?

Aims: Cardiovascular diseases (CVDs) are the leading causes of death among the worldwide. Increased Arterial stiffness could be a robust predictor for coronary heart disease and stroke. Pulsed wave velocity(PWV) is “the most hallowed and still probably the best” measure of arterial stiffness and closely related to the processing of arteriosclerosis. A new ultrasound-based technique, Ultrasound Ultrafast imaging system own a high frame rate over than 2000 frames per second, and could quickly obtain the PWV propagate along the carotid artery wall. The objective of this paper is to detect the carotid artery PWV of elder subjects in vivo, to determine the feasibility and accuracy to assess artery stiffness by Ultrasound Ultrafast imaging. Methods: Ultrasound Ultrafast imaging was performed to obtain the velocity propagate along the left common carotid arteries of fifty-nine (n = 59) healthy volunteers. Including the PWV at the beginning of the systole and at the ending of the systole( BS PWV, ES PWV), the mean PWV( mPWV) were calculated. E-Tracking technology in measuring artery elasticity modulus (PWVβ)and cardio-ankle vascular index(CAVI) were calculated in all subjects. The correlation between parameters from Ultrafast imaging and elastic modulus from e-tracking, CAVI were analyzed. Indicate artery elasticity and the impact of modifying factors such as BMI, age and hypertension. Results: (1) The success rate of the BS PWV, ES PWV were 94.2% and 90.8%,which required a median overall duration of 73s. (2) BMI, age and hypertension were also positively correlated with mPWV ; mPWV were significant positively correlated with PWVβ and CAVI(r=0.68,P&lt;0.01,r=0.48,P&lt;0.05) (3) The mPWV have a good repeatability and conformity. Interobserver and intraobserver variabilities were 4.2% and 3.6 % respectively. Conclusion: The elasticity of carotid artery is the important components of the global arterial elasticity. The decreased elasticity of carotid artery occurs with the ageing and global artery stiffness increased. The Ultrasound Ultrafast imaging is a reliable method to assess the carotid artery stiffness. The technique provides a new, convenient, accurate method for early detection of local artery elasticity.

Regional assessment of carotid artery pulse wave velocity using compressed sensing accelerated high temporal resolution 2D CINE phase contrast cardiovascular magnetic resonance

BackgroundCardiovascular magnetic resonance (CMR) allows for non-invasive assessment of arterial stiffness by means of measuring pulse wave velocity (PWV). PWV can be calculated from the time shift between two time-resolved flow curves acquired at two locations within an arterial segment. These flow curves can be derived from two-dimensional CINE phase contrast CMR (2D CINE PC CMR). While CMR-derived PWV measurements have proven to be accurate for the aorta, this is more challenging for smaller arteries such as the carotids due to the need for both high spatial and temporal resolution. In this work, we present a novel method that combines retrospectively gated 2D CINE PC CMR, high temporal binning of data and compressed sensing (CS) reconstruction to accomplish a temporal resolution of 4 ms. This enables accurate flow measurements and assessment of PWV in regional carotid artery segments.MethodsRetrospectively gated 2D CINE PC CMR data acquired in the carotid artery was binned into cardiac frames of 4 ms length, resulting in an incoherently undersampled ky-t-space with a mean undersampling factor of 5. The images were reconstructed by a non-linear CS reconstruction using total variation over time as a sparsifying transform. PWV values were calculated from flow curves by using foot-to-foot and cross-correlation methods. Our method was validated against ultrasound measurements in a flow phantom setup representing the carotid artery. Additionally, PWV values of two groups of 23 young (30 ± 3 years, 12 [52%] women) and 10 elderly (62 ± 10 years, 5 [50%] women) healthy subjects were compared using the Wilcoxon rank-sum test.ResultsOur proposed method produced very similar flow curves as those measured using ultrasound at 1 ms temporal resolution. Reliable PWV estimation proved possible for transit times down to 7.5 ms. Furthermore, significant differences in PWV values between healthy young and elderly subjects were found (4.7 ± 1.0 m/s and 7.9 ± 2.4 m/s, respectively; p < 0.001) in accordance with literature.ConclusionsRetrospectively gated 2D CINE PC CMR with CS allows for high spatiotemporal resolution flow measurements and accurate regional carotid artery PWV calculations. We foresee this technique will be valuable in protocols investigating early development of carotid atherosclerosis.

Impaired endothelial function and arterial stiffness in patients with type 2 diabetes — The effect of a very low-dose combination of fluvastatin and valsartan

AimPatients with type 2 diabetes are at increased cardiovascular risk. The aim was to explore whether the impaired arterial wall characteristics typical of these patients could be improved by the unique beneficial effects of a very low-dose combination of fluvastatin and valsartan (low-flu/val). MethodsForty middle-aged males (50.4±6.1years) with type 2 diabetes were recruited to a double-blind, randomized study. Patients (N=20) received low-flu/val (10/20mg) or placebo (N=20) over 30days in addition to their regular therapy. Brachial artery flow mediated dilation (FMD), common carotid artery pulse wave velocity (PWV) and β-stiffness were assessed before and after treatment, and 3 and 6months after treatment discontinuation. The treatment was then repeated. ResultsArterial wall characteristics significantly improved. After 30days of intervention, FMD increased from 2.4±0.3 to 4.2±0.3 (p<0.001), PWV decreased from 6.4±0.1 to 5.8±0.2 (p<0.001) and β stiffness decreased from 7.8±0.4 to 6.7±0.4 (p<0.001). Lipids and arterial pressure did not change. After treatment discontinuation, the beneficial effects decreased over the following months. The repetition of treatment completely regained the initial benefits. No changes were observed in the placebo group. ConclusionsLow-flu/val added on-top of optimal therapy substantially improves arterial wall characteristics in patients with type 2 diabetes.

On-line visual feedback of parallel diameter waveforms improves quality of local carotid artery pulse wave velocity measurement

On-line visual feedback of parallel diameter waveforms improves quality of local carotid artery pulse wave velocity measurement

Local carotid artery pulse wave velocity: foot to foot or dicrotic notch?

Local carotid artery pulse wave velocity: foot to foot or dicrotic notch?

Carotid artery pulse wave time characteristics to quantify ventriculoarterial responses to orthostatic challenge

Central blood pressure waveforms contain specific features related to cardiac and arterial function. We investigated posture-related changes in ventriculoarterial hemodynamics by means of carotid artery (CA) pulse wave analysis. ECG, brachial cuff pressure, and common CA diameter waveforms (by M-mode ultrasound) were obtained in 21 healthy volunteers (19-30 yr of age, 10 men and 11 women) in supine and sitting positions. Pulse wave analysis was based on a timing extraction algorithm that automatically detects acceleration maxima in the second derivative of the CA pulse waveform. The algorithm enabled determination of isovolumic contraction period (ICP) and ejection period (EP): ICP=43+/-8 (SD) ms (4-ms precision), and EP=302+/-16 (SD) ms (5-ms precision). Compared with the supine position, in the sitting position diastolic blood pressure (DBP) increased by 7+/-4 mmHg (P<0.001) and R-R interval decreased by 49+/-82 ms (P=0.013), reflecting normal baroreflex response, whereas EP decreased to 267+/-19 ms (P<0.001). Shortening of EP was significantly correlated to earlier arrival of the lower body peripheral reflection wave (r2=0.46, P<0.001). ICP increased by 7+/-7 ms (P<0.001), the ICP-to-EP ratio increased from 14+/-3% (supine) to 19+/-3% (P<0.001) and the DBP-to-ICP ratio decreased by 7% (P=0.023). These results suggest that orthostasis decreases left ventricular output as a result of arterial wave reflections and, presumably, reduced cardiac preload. We conclude that CA ultrasound and pulse wave analysis enable noninvasive quantification of ventriculoarterial responses to changes in posture.

The effects of nisoldipine on carotid artery stiffness and left ventricular functions.

Doppler echocardiographic determination, left ventricular (LV) fractional shortening (FS), cardiac output (CO), diastolic function parameter (E/A ratio) and carotid artery pulse wave velocity and stiffness were evaluated in 36 patients with essential hypertension before and after nisoldipine treatment. Blood pressure decreased significantly, and carotid artery width and fractional shortening increased significantly following nisoldipine administration (p < 0.0001). Carotid artery pulse wave peak velocity did not change following the treatment period (p > 0.05). In conclusion, short term nisoldipine administration improved blood pressure and LV systolic function, whereas LV diastolic function and carotid artery stiffness did not change. Nisoldipine did not alter serum biochemical parameters, including cholesterol, triglyceride, HDL-cholesterol, and LDL-cholesterol (p > 0.05). Only one patient manifested symptoms of hypotension as an adverse effect of the drug.

Timing of the Carotid Arterial Sounds in Normal Adult Men: Measurement of Left Ventricular Ejection, Pre-Ejection Period and Pulse Transmission Time

The first and second carotid arterial sounds (CaS1 and CaS2) were recorded simultaneously with the aortic valve echocardiogram, carotid pulse wave contour, heart sounds, and electrocardiogram in 27 healthy, normal subjects. The mean intervals between the onset of the QRS complex and the onsets of the first and second major components of the carotid arterial sounds were Q-CaS1 = 131 +/- 15 ms and Q-CaS2 = 412 +/- 36 ms, respectively. The mean delay of CaS1 after aortic valve opening was 43 +/- 6 ms, while the delay of CaS2 after aortic valve closure was 43 +/- 7 ms. The onset of CaS1 and CaS2 are exactly coincident with the upstroke and with the dicrotic notch of the carotid pulse wave contour. The recording of the carotid arterial sounds, heart sounds, and ECG has enabled us to measure systolic time intervals including the pre-ejection period, left ventricular ejection time, and pulse transmission time more easily than using the conventional method involving the carotid arterial pulse wave contour. The new approach provides accuracy and precision comparable to that of the previous methods.

Structural pattern recognition of Carotid pulse waves using a general waveform parsing system

A general waveform parsing system with application to structural pattern recognition of carotid pulse waves is described. The carotid arterial pulse wave is of medical importance because of variation in its structure induced by arterial aging and cardiovascular disease. The syntax-driven waveform analysis system has been applied with good results to these pulse waves to detect and measure structural variations. The waveform parsing system is modeled on a compiler-compiler system and allows the user to enter application specific information as data. It is thus general enough to be applicable to other waveforms.

Long-term effect of corticosteroids on cardiac function.

QA2 interval, preejection period and ejection time were calculated from the data of simultaneously recorded ECG, PCG, and external carotid arterial pulse wave in patients with adrenocortical overfunction, namely, Cushing's syndrome and primary aldosteronism, and in patients with nephrotic syndrome or collagen disease under longterm treatments with large doses of glucocorticoids.PEP/ET ratio, which is considered inversely related to the maximal dp/dt of the left ventricle, was markedly increased in the patients with Cushing's syndrome, and in those who were treated with large doses of glucocorticoids for prolonged periods. The PEP/ET ratio in the patients with primary aldosteronism was also increased but not so marked. These results suggest that longterm use of large doses of glucocorticoids impairs the myocardial contractility.

True Venous Pulse Wave

THE classical jugular phlebogram (JP) is a composite record of arterial and venous pulsations. Mackenzie1 noted that if the carotid arterial pulse wave could be subtracted from the JP we would have what he called “the true venous pulse wave”. He was, however, unable to obtain such a record experimentally.