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Biomedical subjects

A P Hoeks

Publications and source records attributed to A P Hoeks.

At least 19 recordsLinked to original sources
PubMed1996

Enhanced cellular proliferation in intact stenotic lesions derived from human arteriovenous fistulas and peripheral bypass grafts. Does it correlate with flow parameters?

BACKGROUND: Vascular interventions are often complicated by the development of intimal thickening, leading to stenosis. Cellular proliferation is a key event in stenosis formation in animals, but the role of cell proliferation in intimal thickening in humans is still unclear. Furthermore, the relation between proliferation in human stenotic lesions and flow parameters has not been established. METHODS AND RESULTS: We studied the proliferation patterns of 35 anatomically intact human stenotic lesions derived from either peripheral bypasses (normal flow) or hemodialysis AV fistulas (high flow) with the use of Ki-67, a cell proliferation marker. Local flow parameters were assessed with ultrasound. Proliferation patterns were similar in AV fistula and bypass stenoses. In the intima, proliferation was highest in the area just below the endothelium (AV fistulas, 3.6%; bypasses, 3.5%; P = NS). In adjacent nonstenotic vessel segments that were used as controls, proliferation rate in the intima was 0.3%. Double-labeling studies revealed that subendothelial-intimal proliferation consisted mainly (90%) of vascular smooth muscle cells, whereas proliferation in the other layers of the vessel wall also consisted of endothelial cells and macrophages. Blood flow velocity was negatively correlated with subendothelial-intimal proliferation (r = -.61, P < .05). The endothelial cell coverage of the lumen was positively correlated with proliferation (r = .85, P < .01). CONCLUSIONS: These data suggest enhanced cellular proliferation in human stenotic tissue derived from AV fistulas and peripheral bypass grafts. Furthermore, high proliferation rates seem to be associated with endothelial cell coverage of the lumen and low local flow velocities.

Adult↗
PubMed1996

A noninvasive method to estimate arterial impedance by means of assessment of local diameter change and the local center-line blood flow velocity using ultrasound.

Vascular impedance is defined as the ratio between the frequency components of the local blood pressure waveform and those of the local blood volume flow waveform. Assessment of vascular impedance is, for example, important to study heart load and distal vascular bed vasomotricity. However, only a few studies on vascular impedance have been performed in humans because pulsatile pressure and volume flow waveforms, simultaneously recorded at the same location, are difficult to obtain noninvasively. The noninvasive assessment of arterial impedance as described in this study is based on the replacement of the pressure waveform by the distension (change in diameter) waveform and the volume flow waveform by the center-line blood flow velocity waveform. Both waveforms can simultaneously and accurately be assessed by means of pulsed ultrasound. It will be shown that, depending on the Womersley number, the volume flow waveform may be replaced by the center-line blood flow velocity waveform for a given frequency range and that the pressure waveform may be replaced by the distension waveform for a wide frequency range. The validation of the proposed ultrasound method was performed through an in vitro study in a flow model with a distensible tube terminated with a hydraulic load (modified windkessel model). It is shown that, in vitro, the proposed method gives the same results as the local spectral pressure-flow relationship.

Arteries↗
PubMed1996

A technique to assess aortic distensibility and compliance in anesthetized and awake rats.

A noninvasive ultrasonic technique, based on tracking arterial wall displacements with a vessel wall-tracking device attached to a conventional B-mode imager, to assess end-diastolic aortic diameter (d) and aortic diameter changes during the cardiac cycle (delta d) in anesthetized and awake rats is presented. From these parameters and invasively measured aortic pulse pressure (delta P), aortic distensibility and compliance, the relative and absolute increases in lumen cross-sectional area for a given increase in delta P, respectively, can be calculated. d, delta d, and delta P could be determined with good intra-session (variations per day) and inter-session (variations between days) coefficients of variation (CV). The CVs for delta d were smaller in awake (4.6-6.0%) than in anesthetized rats (7.9-11.0%), probably due to variations in delta P during anesthesia (CV: 9.0-12.3%). The CVs for d in awake (3.3-6.5%) and anesthetized rats (2.6-5.0%) were comparable. In awake rats the CV for delta d, but not for d, increased after implantation of the aortic catheter. It is concluded that d, delta d, and delta P of the aorta can be reliably measured noninvasively in anesthetized and awake rats, allowing the in vivo assessment of aortic distensibility and compliance. The technique is sensitive enough to detect effects of agents on aortic wall properties.

Adrenergic alpha-Agonists↗
PubMed1996

Prosthetic arteriovenous fistulas and venous anastomotic stenosis: influence of a high flow velocity on the development of intimal hyperplasia.

Stenotic intimal thickening at the venous end of prosthetic arteriovenous (AV) fistulas for hemodialysis has been associated with perianastomotic mismatch in elastic properties between prosthesis and vein and high flow velocities. In a prospective study, we investigated the role of flow velocity on the occurrence of intimal hyperplasia in prosthetic AV fistulas in hemodialysis patients. In 24 patients, the flow velocities were assessed in the distal graft and the outflow vein postoperatively, with the use of vessel wall Doppler tracking, a noninvasive ultrasound technique. The initial velocity in the venous anastomoses was correlated with the occurrence of stenoses during follow-up (2 years). The detection of a stenosis was performed with both Duplex ultrasound and angiography. In 4 cases a stenosis developed in the venous anastomosis, in 8 cases in the venous outflow segment, and in 4 cases at both sites. Higher flow velocities around the venous anastomosis was observed in fistulas developing a stenosis at this site as compared with the nonstenotic fistulas (p < 0.05). The occurrence of stenoses in prosthetic AV fistulas in or adjacent to the venous anastomosis is not associated with a mismatch in elastic properties, but with high flow velocity.

Anastomosis, Surgical↗
PubMed1996

Reduced distensibility of the common carotid artery in patients treated with ergotamine.

To investigate the effect of vascular smooth muscle contraction on mechanical vessel wall properties of proximal "elastic" arteries, we investigated the effect of the vasoconstrictor ergotamine on the distensibility of the common carotid artery in 10 migraine patients with ergotamine intake, in 10 control patients with migraine headache but no prior ergotamine intake, and in 10 healthy control subjects. The patients and control subjects were matched for age, blood pressure, and sex. In the ergotamine group, 2.2 +/- 1.4 mg ergotamine tartrate (0.25 to 6 mg) was taken within 12 hours before investigation. Differences in mean 24-hour blood pressure between the study groups were excluded by 24-hour blood pressure recording and differences in arterial wall thickness by high-resolution and differences in arterial wall thickness by high-resolution B-mode ultrasound. A multigate Doppler system was used for measurement of vessel wall movements by M-mode Doppler analysis. Blood pressure was determined by sphygmomanometry. The end-diastolic diameter of the common carotid artery was insignificantly reduced in the ergotamine group compared with the healthy control subjects and control patients (healthy control subjects, 6.6 +/- 0.4 mm; control patients, 6.7 +/- 0.5 mm; patients with ergotamine intake, 6.3 +/- 0.4 mm; P = NS). Arterial distensibility was significantly lower in the patients with ergotamine intake (17.4 +/- 4.0 10(-3)/kPa) than in the healthy control subjects (22.3 +/- 5.1 10(-3)/kPa) and control patients (22.8 +/- 3.6 10(-3)/kPa) (one-way ANOVA, P = .014). The results show that ergotamine reduces the distensibility of the common carotid artery. The data suggest that vascular smooth muscle contraction can modulate the buffering function of the arterial system independently of blood pressure changes.

Adult↗
PubMed1995

Biophysical principles of vascular diagnosis.

Visual inspection of the spectral composition of the Doppler signal as a function of time (sonogram) has been very helpful in detecting the presence of stenoses with substantial lumen narrowing causing abnormal flow patterns. Attempts to grade a stenosis based on the spectral width at peak systole were less successful because of the obscuring effects of the ultrasound beam width with respect to lumen diameter, dimensions of the sample volume, angle of observation, and spectral broadening due to vessel branching and bends. The introduction of color flow imaging has put emphasis on the width of the velocity distribution and the consistency of flow patterns within the region of interest. This technique requires a high resolution in space, velocity, and time necessitating the development of new velocity estimation algorithms. The observed flow patterns can be related to the echogenicity and local wall thickness of peripheral vessels. In addition, the displacement behavior of arterial walls over time provides information about the elasticity of the wall. Knowing the instantaneous velocity of arterial walls, it becomes possible to suppress selectively and adaptively the arterial wall contribution, allowing for the assessment of low blood flow velocities close to the wall and, hence, of wall shear rate. The latter development enables the study of the interaction of blood velocities and the metabolism and structure of the walls, providing possible clues for atherogenesis.

Algorithms↗
PubMed1995

Acute and subacute effects of nicorandil and isosorbide dinitrate on vessel wall properties of large arteries and hemodynamics in healthy volunteers.

Nicorandil (N) and isosorbide dinitrate (ISDN) are vasodilator drugs used in patients with angina. In 24 healthy male volunteers (18-32 years), the acute effect of a single oral dose (20 mg) of N and ISDN on arterial diameter (D), distensibility, and compliance of the elastic common carotid artery (CCA) and the muscular femoral (FA) and brachial (BA) arteries were investigated. The effects on systolic and diastolic blood pressure (SBP, DBP), heart rate (HR), cardiac index (CI), systemic vascular resistance index (SVRI), and venous hemodynamics were also assessed. In addition, the subacute effects after 8 days of treatment with N (2 x 20 mg/day) and ISDN (3 x 20 mg/day) on these parameters were evaluated. After a 20 mg single oral dose, blood pressure decreased significantly more with ISDN (SBP: 6%; DBP: 14%) than with N (SBP: 2%; DBP: 6%), but after 8 days this decrease in blood pressure was not statistically different between ISDN and N. The diameter of CCA increased more with ISDN (11%) than N (5%) acutely as well as subacutely (ISDN: 12%; N: 9%). Heart rate increased only with ISDN (7% acutely, 3% subacutely). No differences between ISDN and nicorandil were found for acute and subacute effects on SVRI, venous hemodynamics, diameter of muscular arteries (FA, BA), and the distensibility and compliance of elastic (CCA) and muscular (FA, BA) arteries.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1995

Arterial distensibility and compliance in hypertension.

Under normal circumstances arteries, especially the larger elastic ones, distend during systole, and hence are able to store volume energy during this phase of the cardiac cycle. In this way the increase in blood pressure during systole will be leveled off. The amount of energy that can be stored depends not only on the degree of distension (distensibility), but also on the initial diameter of the vessel--two parameters actually determining the compliance of an artery. In both established and borderline hypertension distensibility and compliance of the larger elastic arteries are reduced, as compared with normotensives, but not of the radial artery, at least in patients with established hypertension. In these patients this artery shows a pronounced increase in intima-media thickness. The elastic modulus of the radial artery is not different in hypertensive and normotensive subjects. In the present state of the art, it cannot be concluded whether the loss of artery wall distensibility is caused solely by the increase in blood pressure or that also structural wall changes are involved. In borderline hypertensive patients distensibility and compliance of the elastic arteries are diminished as compared with normotensive subjects. The loss of distensibility already occurs in the fourth age decade and is not homogeneous along the carotid artery bifurcation. The distensibility is significantly lower at all levels in the carotid artery bulb than in the common carotid artery, the proximal part of the bulb, where the baroreceptors are predominantly located, being most affected. This pattern is similar to that observed in normotensive subjects in the sixth age decade, indicating that the carotid arteries age faster in borderline hypertensive than in normotensive subjects.

Adult↗
PubMed1995

The effect of echo suppression on the mean velocity estimation range of the RF cross-correlation model estimator.

Ultrasound systems are widely used to visualize in real-time internal structures and blood flow velocity distributions. The latter are estimated from the received ultrasound radio frequency (RF) signals using a mean frequency estimator, capable of estimating the temporal and spatial mean frequency within a given depth and time window (estimation window). Since ultrasound RF-signals are composed of three major signal components (reflections, scattering and noise) it is necessary to suppress the power of the reflections or reverberations (stationary echo removal) to estimate the temporal mean frequency of the signal component induced by scattering originating from red blood cells. However, the stationary echo removal filter in front of the mean frequency estimator will restrict the temporal mean frequency estimation range because the power of the signal component induced by the slowly moving blood is suppressed as well. This article describes a stationary echo removal filter, acting in the RF-domain and adaptive to the temporal mean frequency of the signal component induced by stationary or slowly moving reflections and reverberations. Furthermore, a comparison in performance of this adaptive stationary echo removal filter and several static stationary echo removal filters is presented. For direct comparison of these filter algorithms as far as the effect on the temporal mean frequency estimation range is concerned, the same signal conditions in combination with the same RF-domain mean frequency estimator were used in this comparison. It could be demonstrated that the adaptive echo removal filter, in combination with the RF-domain mean frequency estimator used, exhibits the best performance.

Blood Flow Velocity↗
PubMed1995

A noninvasive method to estimate wall shear rate using ultrasound.

Wall shear stress (blood viscosity x wall shear rate), imposed by the flowing blood, and blood pressure are the main mechanical forces acting on a blood vessel wall. Accurate measurement of wall shear stress is important when investigating the development of vascular disease, since both high and low wall shear stresses have been cited as factors leading to vessel wall anomalies. Furthermore, in vitro studies have shown that endothelial cells, which play a key role in the function of the underlying arterial wall, undergo a variety of structural and functional changes in response to imposed shear stress. However, there is practically no knowledge about the influence of wall shear stress on the arterial wall in vivo because of the difficulty in measuring this stress in terms of magnitude and time variation. The method presented in this article to measure the time-dependent wall shear rate in the main arteries is based on the evaluation of velocity profiles determined by means of ultrasound, using off-line signal processing. Pulsed ultrasound is well suited for this application since it is noninvasive. The processing performed in the radio-frequency (RF) domain consists of a mean frequency estimator preceded by an adaptive vessel wall filter. In a pilot study (30 measurements in the carotid artery of five healthy volunteers) we investigated the reproducibility of our method to estimate wall shear rate as compared with the reproducibility of the measurement of blood flow velocity in the middle of the vessel. The coefficient of variation was on the order of 9% for blood flow velocity estimation, and for wall shear rate estimation on the order of 5%.

Adolescent↗
PubMed1995

The influence of perindopril and the diuretic combination amiloride+hydrochlorothiazide on the vessel wall properties of large arteries in hypertensive patients.

OBJECTIVE: To compare the cardiovascular effects of 6 months of treatment with the angiotensin converting enzyme inhibitor perindopril and with the diuretic combination amiloride+hydrochlorothiazide, and to study possible persistence of observed treatment effects after discontinuation of antihypertensive therapy. DESIGN: A placebo run-in period preceded a 6-month active-treatment phase in 41 patients with essential hypertension, according to a double-blind, randomized, parallel-group design. Patients received either 4 mg perindopril or 2.5/25 mg amiloride+hydrochlorothiazide once a day. Patients were then studied for a 3-month single-blind placebo run-out period. RESULTS: After 6 months of treatment, systolic blood pressure was reduced significantly by perindopril (supine by 11%, sitting by 10%) and by amiloride+hydrochlorothiazide (supine by 8%, sitting by 12%). Diastolic blood pressure was also decreased significantly by perindopril (supine by 8%, sitting by 11%) and by amiloride+hydrochlorothiazide (supine by 4%, sitting by 9%). Mean arterial pressure decreased significantly during treatment with perindopril (by 9%) and with amiloride+hydrochlorothiazide (by 6%). Cardiac index increased with perindopril (by 6%), because of an increased stroke index (by 5%), but amiloride+hydrochlorothiazide did not change cardiac function. Systemic vascular resistance index decreased significantly more with perindopril (by 14%) than with amiloride+hydrochlorothiazide (by 8%). The distensibility of the common carotid artery was significantly enhanced by perindopril (by 16%), but not changed by amiloride+hydrochlorothiazide (1% difference). The difference between perindopril and amiloride+hydrochlorothiazide for carotid distensibility was statistically significant. The compliance of the common carotid artery tended to be increased more by perindopril (by 7%) than by amiloride+hydrochlorothiazide, which induced a 5% decrease in carotid compliance. After withdrawal of therapy, for both drugs, all treatment-induced changes were reversed to pretreatment values within 7 weeks. CONCLUSION: The distensibility of the elastic common carotid artery was increased by perindopril, but not by amiloride+hydrochlorothiazide. Large-artery properties of the muscular arteries and systemic vascular resistance improved with both drugs, but in general the changes were more pronounced with perindopril than with amiloride+hydrochlorothiazide. The present results indicate a more pronounced effect of perindopril at both macro- and microcirculatory levels, which will consequently lead to a larger decrease in cardiac afterload. After discontinuation of therapy all parameters returned to baseline values within 7 weeks.

Adult↗
PubMed1995

Noninvasive determination of shear-rate distribution across the arterial lumen.

In vitro experiments have shown that the shear stress exerted by flowing blood on the endothelial surface affects the morphology of the vascular wall and the release of vasoactive substances and growth factors by that wall. It is believed that the caliber of a vessel adjusts to the local shear stress to maintain a specific value of the shear stress. The local shear stress follows from local shear rate by multiplying shear rate by the local blood viscosity. The present article describes a method in which ultrasound techniques are used to assess transcutaneously the time-dependent wall shear rate in vivo in arteries. This method is applied to the assessment of wall shear rate in the common carotid artery of volunteers, presumed to be healthy, in two age categories (young age group, 20 to 30 years old, n = 8; old age group, 60 to 70 years old, n = 6). Although the peak shear rate in the young age group is markedly higher than in the old age group, the mean shear rate averaged over a cardiac cycle has the same value of 210 s-1 for both groups, corroborating earlier observations that mean shear rate and, hence, mean shear stress are maintained at a particular value. Conversion of the observed shear rates to shear stresses, assuming a blood viscosity of 3.5 mPa.s for both age groups, gives shear stresses of approximately 0.7 Pa. This is a factor of two lower than the shear stresses estimated from the relation between volume flow and artery caliber (1.5 Pa).

Adult↗
PubMed1995

Aortic wall properties in normotensive and hypertensive rats of various ages in vivo.

The distensibility of the arterial system, which is partly determined by arterial wall structure, smooth muscle tone, and actual pressure level, decreases with aging and hypertension. Our aim was to compare aortic wall properties in 3- and 6-month-old normotensive Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR) at comparable blood pressures in vivo. During ketamine/xylazine anesthesia in rats we performed ultrasound arterial wall tracking and invasive pressure measurements to determine, at the level of the thoracic aorta, diastolic pressure, diastolic lumen area, changes in pressure and lumen area during the cardiac cycle, and indexes of compliance and distensibility. These observations were combined with histological measurements for determination of media cross-sectional area and thickness and the incremental elastic modulus under conditions as expected in situ. Anesthesia abolished the difference in diastolic pressure between SHR and WKY. Between 3 and 6 months of age in WKY, diastolic area and incremental elastic modulus increased significantly, distensibility decreased, and all other recorded variables were not modified. Between 3 and 6 months of age in SHR, diastolic area and incremental elastic modulus increased, distensibility of the aortic wall decreased, and all other mechanical and structural properties did not change significantly. At both ages, diastolic area and compliance were significantly smaller in SHR than WKY. The other mechanical and structural properties measured or calculated at comparable pressure did not differ between strains. Differences between the aorta of 3- and 6-month-old rats and between strains observed in vivo at comparable pressures can largely be attributed to differences in lumen caliber.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1995

Improved lesion detection by level-dependent spatial summation.

A novel signal postprocessing method has been developed for application in lesion detection. A signal distribution, directly related to the 2-dimensional envelope distribution comprising a B-mode image, is convolved with a block shaped kernel of which both base area (i.e. window size) and height are modulated by the local signal level. A theoretical analysis shows that the output includes information regarding the local mean brightness in the original image. This information can be displayed as a gray scale image. The predicted behavior agrees with experimental observations. On the basis of twenty simulated lesion images, it is demonstrated that the present algorithm is superior to the conventional L2-mean filter in lesion detection problems, whereby the performance is quantified by the area AROC under the Receiver Operating Characteristic. An improvement in the median value of AROC of the order of 0.1 was observed. Two parameters are used for adjustment. The total number of summations involved in the processing of a frame is comparable to the number required by the arithmetic mean filter, allowing real-time implementation.

Algorithms↗
PubMed1995

Anastomotic intimal hyperplasia in prosthetic arteriovenous fistulas for hemodialysis is associated with initial high flow velocity and not with mismatch in elastic properties.

Stenotic intimal thickening at the venous end of prosthetic arteriovenous (AV) fistulas for hemodialysis has been associated with perianastomotic mismatch in elastic properties, and low shear rates. In a prospective way, the role of these factors on the occurrence of intimal hyperplasia in prosthetic AV fistulas in hemodialysis patients was investigated. In 24 hemodialysis patients, the elastic properties were assessed in the distal graft segment and the outflow vein postoperatively with the use of Vessel Wall Doppler Tracking (VWDT), a noninvasive ultrasound technique. In addition, normalized peak systolic velocity (nPSV) was calculated from diameter (VWDT) and peak systolic velocity. The initial mismatch around the venous anastomoses and local nPSV were correlated with the occurrence of stenoses during follow-up (2 yr). The detection of a stenosis was performed with both Duplex ultrasound and angiography. In four cases, a stenosis developed in the venous anastomosis; in eight cases, a stenosis developed in the venous outflow segment; and in four cases, stenoses developed at both sites. A better initial match in elastic properties around the venous anastomosis was observed in the fistulas developing a stenosis at this site as compared with the nonstenotic fistulas (P < 0.05). The initial local nPSV values at the site of the later stenosis were higher in the fistulas developing a stenosis as compared with the nonstenotic fistulas (P < 0.05). It was concluded that the occurrence of stenoses in prosthetic AV fistulas for hemodialysis in or adjacent to the venous anastomoses is associated with a high initial flow velocity but not with a mismatch in elastic properties.

Adult↗
PubMed1995

Vessel wall properties of large arteries in uncomplicated IDDM.

OBJECTIVE: Patients with insulin-dependent diabetes mellitus (IDDM) are at high risk for cardiovascular disease. Arterial distensibility and compliance are vessel wall properties of large arteries. Altered large artery wall properties can be an early feature of vascular dysfunction. This study investigates vessel wall properties in 30 patients with uncomplicated IDDM and 30 matched healthy control subjects. RESEARCH DESIGN AND METHODS: Vessel wall properties of the elastic common carotid (CCA) and the muscular femoral (FA) and brachial arteries (BA) were measured with a vessel wall movement detector system. Blood pressure and heart rate were recorded simultaneously with a semiautomated device. Aortic pulse wave velocity was estimated from the carotido-femoral transit time. RESULTS: Blood pressure (IDDM patients: 118 +/- 10/69 +/- 5 mmHg), pulse pressure (IDDM patients: 49 +/- 8 mmHg), and heart rate (IDDM patients: 65 +/- 9 beats/min) were similar in IDDM patients and control subjects. No statistically significant changes between IDDM patients and control subjects were found for diameter, distensibility, and compliance of the elastic CCA and the muscular BA. Distensibility (IDDM patients: 16.9 +/- 6.4 10(-3)/kPa; control subjects: 22.4 +/- 11.8 10(-3)/kPa) of the muscular FA was decreased in IDDM (P < 0.05). However, FA compliance (IDDM patients: 0.80 +/- 0.23 mm2/kPa; control subjects: 0.94 +/- 0.41 mm2/kPa) and FA diameter (IDDM patients: 7.87 +/- 1.10 mm; control subjects: 7.57 +/- 1.11 mm) did not differ statistically between IDDM patients and control subjects. Aortic pulse wave velocity was the same in IDDM patients and control subjects (IDDM patients: 5.1 +/- 0.6 m/s). No relation was found between vessel wall properties and duration of disease, actual glucose level, and HbA1c for all three arteries (CCA, BA, and FA). But the groups might have been too small to draw conclusions. CONCLUSIONS: The results of the present study show that in this group of patients with uncomplicated IDDM, vessel wall properties of elastic and muscular large arteries were not obviously reduced when compared with healthy control subjects. However, distensibility of the FA was lower in IDDM patients. Early atherosclerotic changes in IDDM frequently occur at this site. A difference related to the duration of diabetes could not be excluded.

Adolescent↗
PubMed1995

Different effects of hypertension, atherosclerosis and hyperlipidaemia on arterial distensibility.

OBJECTIVE: To investigate the different effects of hypertension, hyperlipidaemia and atherosclerosis on the visco-elastic properties of large arteries. DESIGN: Vessel wall properties were determined in patients who had been subjected for the first time to coronary arteriography. Normotensive patients with no coronary disease (n = 15), one-vessel disease (n = 15) or two- or three-vessel disease (n = 15), 15 treated hypertensive patients (mean +/- SEM duration of hypertension 9.6 +/- 1.7 years) with no coronary disease and normocholesterolaemia and 15 healthy controls were matched for blood pressure, age and sex. METHODS: Arterial distension of the common carotid artery was determined by using a multigate Doppler system. The blood pressure curve was recorded by finger plethysmography. RESULTS: The end-diastolic diameter was significantly higher in the hypertensives (P<0.05) but not significantly different in the normotensives compared with the controls. Arterial distensibility was significantly lower in the hypertensive group [(13.3 +/- 0.8) x 10(-3)/kPa] than in the controls [(19.1 +/- 1.5) x 10(-3)/kP; P<0.01), in the group with no coronary disease [(18.8 +/- 1.3) x 10(-3)/kPa; P<0.01] and in those with one-vessel disease [(17.7 +/- 1.4) x 10(-3)/kPa; P<0.05]. Arterial distensibility was not significantly lower in the hypertensives than in the group with two- or three-vessel disease [(15.0 +/- 1.0) x 10(-3)/kPa; NS). No significant correlation was found between cholesterol or lipoprotein(a) levels and arterial distensibility in the normotensive patients. CONCLUSIONS: Hypertension is the predominant factor affecting the visco-elastic properties of large arteries. Arterial compliance is significantly altered only in extensive atherosclerosis.

Arteriosclerosis↗