Biomedical subjects

B Pannier

Publications and source records attributed to B Pannier.

At least 55 records · Page 3Linked to original sources

PubMed1992

Acute changes in forearm haemodynamics produced by cigarette smoking in healthy normotensive non-smokers are not influenced by propranolol or pindolol.

The aim of the present study was to examine the effect of cigarette smoking in healthy non-smokers on blood pressure and forearm haemodynamics after acute oral administration of non-selective beta-adrenoceptor blockers with and without intrinsic sympathomimetic activity, viz. pindolol 15 mg and propranolol 80 mg. A preliminary study was done to compare cigarette smoking and sham smoking to evaluate the time-course of the haemodynamic effects of cigarette smoking. The second experiment was then carried out in the same six volunteers, according to a double-blind randomized placebo-controlled crossover design, to evaluate the possible effect of pre-treatment with beta-adrenoceptor blockers on blood pressure, heart rate and forearm haemodynamics (forearm blood flow, brachial artery diameter and brachio-radial pulse-wave velocity) measured at baseline, during smoking and every five minutes up to 1 h afterwards. No major difference from placebo in blood pressure or forearm haemodynamics was found and pre-treatment with beta-blockers did not prevent the acute vascular effects of cigarette smoking.

Adult↗

PubMed1992

Increased systolic pressure in chronic uremia. Role of arterial wave reflections.

To assess the role of arterial wave reflections in the mechanism of systolic hypertension and altered pulsatile arterial dynamics in patients with end-stage renal disease (ESRD), 79 ESRD patients were compared with 73 age-matched control subjects with normal renal function and similar mean blood pressure. Wave reflections were investigated from the carotid pulse contour recorded by applanation tonometry using a Millar micromanometer-tipped probe. Wave reflections were quantified as the ratio (augmentation index, %) of the height of the late systolic peak to the total height of carotid pulse wave. Travel time of the reflected wave was timed from the foot of the pressure wave to the foot of the late systolic peak. Systolic and pulse pressure were increased in ESRD patients (p less than 0.001) and was not attributable to differences in left ventricular ejection pattern. The augmentation index was increased in ESRD patients (23.2 +/- 15.0 versus 9.8 +/- 15.6%; p less than 0.001) in association with a shorter travel time of reflected wave (109 +/- 24 versus 131 +/- 30 msec; p less than 0.001). Multiple regression analysis showed two principal factors associated (p less than 0.001) with the increase in augmentation index and shortened travel time of reflected wave: increased aortic pulse wave velocity and smaller stature with shorter body height in ESRD patients. The study points to the role of arterial wave reflections in the mechanisms producing alterations in pulsatile arterial dynamics in ESRD and is the first, through the mechanisms of early wave reflections, to show in humans that the increase in systolic and pulse pressures is associated with lesser body size.

Adult↗

PubMed1992

[Nitrate derivatives and compliance of large arteries].

Nitrate derivatives are useful drugs because of their direct vasodilating properties even in the presence of abnormal endothelial function. This is particularly true of the great arteries, explaining the improvement in arterial compliance regularly observed. The corollary of this effect is an improvement in systolic blood pressure and arterial pulsatility with little change in mean arterial pressure. The improved systolic but unchanged mean blood pressures reduce myocardial systolic stress and ensure relative preservation of coronary perfusion pressure which is particularly important in the treatment of systolic hypertension of the elderly.

Blood Pressure↗

PubMed1992

[Non-invasive methods in the study of the elastic properties of the thoracic aorta. Effect of isosorbide dinitrate].

The role of the great arteries is to distribute and stock blood. Pulsatile discontinuous flow is transformed to a continuous flow system. The elastic properties of the aorta play a major role in these functions. It is generally agreed that changes in these elastic properties may lead to the development of left ventricular hypertrophy. The evaluation of the aorta has, until recently, depended on invasive hemodynamic and angiographic techniques. In addition, the measurement of pulse wave velocity, though useful, is a global and only an approximate method. Transoesophageal echocardiography (TEE) enables accurate measurement of the aortic diameter and its systolo-diastolic variations. The accuracy of these measurements has been validated in vitro and the reproducibility is much better than with previously used techniques. Previous studies have shown an improvement of the elastic properties of the great arteries with nitrate derivatives. In recent studies using TEE, isosorbide dinitrate caused dilatation of the descending thoracic aorta and thereby improved its elastic properties. The development of tonometry techniques in our department has resulted in the finding of excellent correlations between carotid and aortic pulse pressures measured non-invasively. The association of TEE and tonometry thereby provides a direct approach to the evaluation of aortic compliance. It has then become possible to study the effects of nitrate derivatives on the aortic compliance of elderly patients in whom it is the most reduced.

Aorta, Thoracic↗

PubMed1991

Arterial distensibility and left ventricular hypertrophy in patients with sustained essential hypertension.

Reduced aortic distensibility and compliance may participate in the genesis of cardiac hypertrophy in patients with hypertension. In these patients the increase in end-systolic stress, a determinant factor contributing to the development of cardiac hypertrophy, is influenced not only by the geometric properties of the ventricle but also by the level of systolic pressure. In patients with sustained essential hypertension, the degree of cardiac hypertrophy correlates significantly with the increase in aortic rigidity, which is assessed by the calculation of the characteristic impedance, by the measurement of carotid-femoral pulse-wave velocity, or by the calculation of the Peterson elastic modulus at the level of the aortic arch. Dihydralazine-like substances are unable to modify arterial stiffness, whereas calcium-entry blockers and converting-enzyme inhibitors improve arterial stiffness when achieving the same degree of blood pressure reduction. Modifications in the stiffness of the aorta and other large arteries must be considered to understand reversion of cardiac hypertrophy as a result of antihypertensive treatment.

Antihypertensive Agents↗

PubMed1990

Flow-dependent vasodilation of brachial artery in essential hypertension.

Brachial artery hemodynamics including brachial artery diameter (D) and local blood flow velocity (V) was studied in 15 normotensive subjects (NT) and 19 age-matched hypertensive patients (HT) at rest using a bidimensional pulsed Doppler system during a 2-min period of distal circulatory occlusion and during reactive hyperemia. Kinetics of changes in V and D were determined during successive and reproducible maneuvers. V and D decreased significantly during distal circulatory occlusion in both groups. During reactive hyperemia, V reached similar maximum values in both groups, and D increased significantly in NT and HT. Changes in D during reactive hyperemia were positively and significantly correlated with changes in V recorded at the same level. No significant difference was found between the two groups. These results demonstrate noninvasively that there are velocity-dependent variations in the diameter of a large artery in humans and suggest that velocity-dependent vasodilation of the brachial artery is not impaired in essential hypertension.

Adult↗

PubMed1990

[Methods for studying vasodilator agents in arterial hypertension].

The concept of vasodilatation has evolved with regards to the treatment of hypertension. Large multicentre trials have shown that decreasing mean arterial pressure alone does not reduce coronary morbidity and mortality related to hypertension. The authors suggest that the haemodynamic abnormalities related to hypertensive disease were not totally reversed by the antihypertensive agents used in these trials. Regression of structural arterial changes, regression of LVH without altering systolic function, reduction of the variability of blood pressure and maintenance of regional blood flow should all be objectives of any antihypertensive vasodilator therapy. Methods of studying vasodilators are described and the effects of the main classes of antihypertensive drugs on these parameters are analysed.

Antihypertensive Agents↗

PubMed1990

Haemodynamic effects of perindopril in essential hypertension.

Blood pressure, forearm arterial haemodynamics and echocardiographic parameters were studied in patients with sustained essential hypertension before and after administration of the ACE inhibitor, perindopril. In a single blind study versus placebo, perindopril significantly reduced BP and at the same time increased brachial artery diameter, blood flow and compliance. As part of the haemodynamic investigation, a 5 minute wrist occlusion was performed. During this period, blood flow velocity and arterial diameter decreased but the reduction in diameter was smaller with perindopril after one year's treatment showing an increase in brachial artery diameter. This result indicates that the increase in brachial arterial diameter following perindopril could not be explained solely on the basis of a flow dependent dilation. When perindopril was withdrawn after three months of treatment and replaced by placebo for four weeks, BP and forearm arterial haemodynamics returned towards baseline values. However, cardiac mass which was significantly decreased after perindopril remained decreased four weeks after cessation of treatment. In the seven normalised patients, perindopril was continued for one year; arterial compliance remained increased and cardia mass diminished. The study showed that the arterial changes caused by perindopril involved a drug-related relaxation of arterial smooth muscle and that there was a differential response in cardiac and arterial changes following long term treatment.

Adult↗

PubMed1990

[Magnetic resonance imaging in the diagnosis of pheochromocytoma].

The diagnosis of pheochromocytoma is biological. If ultrasound enables the visualization of certain adrenal tumours or hepatic metastasis, in fact two tests enable the topographic diagnosis, the screening of ectopic localizations and metastasis. They are IMBG scintigraphy and tomographic scanning. The place of magnetic resonance imaging is not yet specified. However, it has many advantages: absence of irradiations, good anatomic precision, meticulous screening of ectopic forms, of metastases and of adenopathies, study of the tissue characterization, good definition of the tumour relation with the vascular pedicles and the neighbouring structures.

Adrenal Gland Neoplasms↗

PubMed1989

Vascular changes in hemodialysis patients in response to recombinant human erythropoietin.

The partial correction of anemia with recombinant human erythropoietin (rHuEpo) is frequently associated with an increase in arterial pressure and could oppose the beneficial effect of anemia correction on myocardial function. In order to analyze the influence of rHuEpo therapy on the vessels and the heart, we performed systemic and regional hemodynamics studies in 11 hemodialysis patients before and 10 to 35 weeks after initiation of rHuEpo therapy, when hemoglobin concentration was 6.8 +/- 0.9 and 10.6 +/- 0.66 g/dl (mean +/- SD), respectively. The mean arterial pressure remained unchanged during this period (88 +/- 21 vs. 88 +/- 15 mm Hg). Echocardiographic study showed that rHuEpo treatment led to a decrease in left ventricular end-diastolic diameter (4.9 +/- 0.5 vs. 5.1 +/- 0.6 cm; P less than 0.03), left atrial diameter (3.22 +/- 0.30 vs. 3.43 +/- 0.33; P less than 0.03), and left ventricular mass index (109.8 +/- 30.6 vs. 133 +/- 30.8 g/m2; P less than 0.05). Left ventricular ejection volume decreased from 86 +/- 24 to 75 +/- 19 ml (P less than 0.03) and heart rate from 76 +/- 9 to 70 +/- 10 beats/min (P less than 0.05). Cardiac index decreased from 4715 +/- 700 to 3635 +/- 444 ml/min/m2 (P less than 0.01) and peripheral resistances rose from 1480 +/- 162 to 1943 +/- 250 dynes.sec.cm-5.m2 (P less than 0.01). Fractional ejection and mean circumferential fiber shortening remained unchanged. The treatment with rHuEpo did not change the aortic diameters.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1989

Effects of twenty-four hours of bed rest with head-down tilt on cardiopulmonary baroreflex control: preliminary study.

The cardiopulmonary baroreflex response was studied before and after 24 h bed rest with head-down tilt (-5 degrees) in six normal male subjects, through lower body negative pressure (-5, -10, -15 mmHg) and passive leg raising. The reflex response was assessed (using plethysmography) by changes in forearm vascular resistance. During the lower body negative pressure and leg raising, forearm vasoconstriction and vasodilation were similar before and after head-down tilt. The study shows that orthostatic intolerance following head-down tilt is not explained by an abnormality in the response of low pressure baroreceptors.

Adult↗

PubMed1989

Calcium-entry blockers and arterial compliance in hypertension.

Calcium-entry blockers dilate small arteries as well as large arteries, particularly in the brachial and the carotid circulations. This dilating effect is associated with an increase in systemic and brachial arterial compliance, which is poorly related to the level in blood pressure. Calcium-entry blockers are able to reverse the reduced arterial compliance observed in patients with essential hypertension, with important consequences to the structure and function of the heart and large vessels.

Arteries↗

PubMed1989

[Venous tone of the limbs. Methods and comparison of 2 areas].

The limb venous tone, index of local venous compliance, was studied with mercury strain gauge plethysmography on 28 male normal subjects (40 +/- 17 years, +/- SD) simultaneously on upper and lower limbs. Measurements were done after 20 mn rest in supine position. Venous tone (VT) equals the slope of the pressure-volume curve established by simultaneous recording of the forearm and calf relative volumes for successive steps of pressure lower than or equal to 30 mmHg. Limb venous capacitance was expressed by means of the maximal limb relative volume (V30) reached for a pressure of 30 mmHg applied through cuffs in standardized conditions. The upper limb venous tone was greater than the lower limb venous tone: 24.3 +/- 8.2 mmHg/ml/100 vs 17.5 +/- 7.9 mmHg/ml/100, p = 0.001. V30 was greater in lower limb than in upper limb: 1.5 +/- 0.5 ml/100 vs 1.1 +/- 0.4 ml/100, p = 0.001. In conclusion, it appears that upper and lower limbs venous distensibility and capacitance are different. They are greater in the lower limb in baseline conditions. Thus simultaneous studies of both these limb venous systems seems important for physiological experiments because of their baseline differences.

Adult↗

PubMed1989

[Effects of rilmenidine on arterial parameters in essential arterial hypertension].

Rilmenidine (RIL) is a new antihypertensive agent which lowers sympathetic tone, so reducing systemic peripheral resistance. The effects of a single dose of RIL (1 mg) on arterial function were the object of a preliminary randomised double-blind versus placebo trial in 14 patients with hypertension after a one month washout period on placebo. The following parameters were recorded before (T0) and 4 hours after administration (T4): blood pressure, heart rate (automatic recordings), diameter of the humeral artery (D), mean blood flow velocity (Vm) by an 8 MHz duplex pulsed Doppler system, local forearm resistances (LR = mean BP/D2 Vm/4), carotid-femoral pulse wave velocity (PWV) and humeral arterial wall tension (mean BP.D/2). The two groups were compared by statistical analysis of variance with two crossed factors. RIL significantly lowered systolic BP (p less than 0.02), diastolic BP (p less than 0.05) and mean BP (p less than 0.01) without changing the heart rate. The D and PWV were unchanged in the RIL group. There was a significant improvement in arterial wall tension (-6.7% vs + 1.1%; p = 0.02) associated with a tendency to increase the PWV (45% vs 4%; p = 0.097) and to decrease LR (46% vs 10%; p = 0.062) although those changes were not statistically significant compared with those observed with placebo. These initial results indicate that the hypotensive effect of RIL is accompanied by a reduction in humeral arterial wall tension which occurs without any change in arterial diameter. This also reflects a change in the pressure-volume relationship with RIL.(ABSTRACT TRUNCATED AT 250 WORDS)

Antihypertensive Agents↗

PubMed1989

Pulse pressure and echocardiographic findings in essential hypertension.

Blood pressure, carotid-femoral pulse wave velocity and cardiac mass as judged on echocardiography were evaluated in 11 normal subjects and 36 patients with sustained essential hypertension of similar age. The hypertensive patients were divided into two groups of similar age, weight, height and mean arterial pressure: patients in the first group (Group I) had a pulse pressure inferior to 60 mmHg and in the second group (Group II) had a pulse pressure equal or superior to this value. Group II patients had significant higher values for cardiac mass (148.8 +/- 44.3 vs 116.3 +/- 19.8 g/m2; P less than 0.01) (+/- 1 s.d.) than Group I, while mean arterial pressure and pulse wave velocity were similar in the two groups. Stroke volume was significantly higher in Group II than in normal subjects (99.5 +/- 17.1 versus 82.7 +/- 16.9 ml; P less than 0.05). The study findings suggested that the increased pulse pressure in hypertensive patients might influence the development of cardiac hypertrophy independently of mean arterial pressure and aortic distensibility. The increased pulse pressure could reflect a disturbance between ventricular ejection and impedance affecting the ventricle with a resulting increase in pulsatile energy losses and further increase in cardiac mass.

Adult↗

PubMed1989

[Spontaneous dissection of the renal artery].

In this paper we describe a case involving spontaneous dissection of the renal artery (DRA) successfully treated with an aorto-renal venous graft. DRA is a rare disorder which strikes men especially. Hypertension is the most frequent sign of its presence, which is usually of sudden onset, and with major adverse impact on the eye and brain. Arteriography is the key diagnostic examination. The most typical image is that of "cuffing". Treatment is surgical in nearly 50% of cases and should be as conservative as possible since these lesions may be bilateral.

Aortic Dissection↗

PubMed1988

Dose and concentration-effect relations for rilmenidine.

The dose-effect and concentration-effect relations of rilmenidine, a new alpha 2 agonist, were evaluated for the hemodynamic and side-effect responses to single oral doses. Two studies were performed in a double-blind manner: study I in 8 healthy subjects and study II in 10 hypertensive patients. In the course of five 24-hour periods, each separated by at least 1 week, the following 5 treatments were administered in a random order: placebo, rilmenidine (0.5, 1, 2 and 3 mg). Blood pressure was measured with a Roche arteriosonde (study I) or a sphygmomanometer (study II). Sedation was measured using a visual analog scale. Dry mouth was assessed by measuring the salivary flow (study I) or by visual analog scale (study II). Plasma concentration of rilmenidine was assayed by gas chromatography linked with mass spectrometry. The antihypertensive and sedative effects (area under curve) were directly related to the dose and to the log of the plasma concentration of rilmenidine. In contrast to the 2- and 3-mg doses, rilmenidine (0.5 and 1 mg) did not induce orthostatic hypotension, a significant decrease in heart rate or a significant dryness of mouth. At doses of 0.5 and 1 mg, the effects of rilmenidine on sedation were not consistent in both studies: sedation was significant in study I but did not differ from placebo in study II. These studies show that rilmenidine, in common with other alpha 2 agonists, decreases blood pressure in a dose-dependent manner, in normotensive as well as in hypertensive subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗

PubMed1988

Sodium and large arteries in hypertension. Effects of indapamide.

Epidemiologic studies evaluating arterial pulse wave velocity together with blood pressure indicate that: (1) salt intake has an independent effect on arteriolar tone and arterial wall properties, with the former indirectly and the latter directly contributing to increased arterial stiffness with age; and (2) normotensive adult subjects who follow a low sodium diet have reduced arterial stiffness and this effect is independent of blood pressure. Conversely, in elderly persons with isolated systolic hypertension, isotonic saline infusion causes a predominant increase in systolic pressure due to an increase in the stiffness of the arterial wall. The diuretic indapamide produces a decrease in blood pressure without significant change in brachial artery diameter. The result indicates a shift of the pressure-diameter curve, reflecting for the first time in humans a pharmacologic effect of the drug on arterial vessel. Furthermore, diuretic drugs may increase arterial distensibility and compliance in hypertensive patients, but this effect seems to be more pronounced in older than in younger subjects. In the latter, either activation of the sympathetic nervous system or potassium depletion, or both, might counteract the improvement in arterial distensibility caused by blood pressure reduction and sodium depletion. Based on epidemiologic, clinical, and pharmacologic studies, this critical review suggests that, in patients with essential hypertension, changes of sodium intake in diet or administration of diuretics, or both, affect the status of large arteries independently of blood pressure changes.

Aging↗