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Biomedical subjects

R Asmar

Publications and source records attributed to R Asmar.

105 records · Page 6Linked to original sources
PubMed1988

Converting enzyme inhibition and the common carotid circulation in older patients with sustained essential hypertension.

Arterial diameter, blood flow and vascular resistance of the common carotid artery were studied using a pulsed Doppler system in patients with uncomplicated sustained essential hypertension and compared with age-matched normal subjects. In hypertensive patients below the age of 45 years, arterial diameter and blood flow remained within the normal range, while vascular resistance was increased. In hypertensive patients over 45 years of age, arterial diameter was also normal, but blood flow was reduced and vascular resistance markedly increased. Thus, both small and large arteries were altered in the common carotid circulation of patients with sustained essential hypertension. Acute oral administration of converting enzyme inhibitor produced dilatation of both small (vascular resistance) and large (arterial diameter) arteries in the carotid circulation. In addition, in older patients, blood flow significantly increased and vascular resistance markedly decreased both in acute and long-term situations. Thus converting enzyme inhibition was able to reverse the abnormalities of the common carotid circulation of older subjects with sustained essential hypertension.

Adult↗
PubMed1988

[Non-invasive ambulatory blood pressure measurement over 24 hours: effects of labetalol on the rise of blood pressure in the early morning].

Three french specialist centers have included 19 hypertensive patients in an open cooperative study of the effect of labetalol (L = 200 to 400 mg b.i.d.) on the 24 hour blood pressure (24 h - B.P.) recording by a non invasive method (Spacelabs - Squibb Medical Systems), with a particular assessment of the early morning rise of BP. Each patient was subjected to 2 assessments at the end of a 14 days' placebo period and of a 28 days' treatment period. At the end of the study, the systolic (SBP) and diastolic (DBP). B.P. were significantly decreased at rest (p less than 0.001) and on the 24 hours recording (p less than 0.001). The reduction of B.P. was also significant on day period from 7 a.m. to 22 p.m. (p less than 0.001) and night period from 22 a.m. to 7 a.m. (p less than 0.05) as well as on the early morning period, 3 hours before and after waking (p less than 0.001). The heart rate was significantly reduced during the day (p less than 0.05) and was not on the night. The slope of the early morning rise of B.P. was marked after placebo and significantly decreased after labetalol with a reduction of 52% for SBP and 49% for DBP (p less than 0.001). These results show that labetalol has an antihypertensive effect over 24 hours with a marked effect on the early morning rise of B.P.

Adult↗
PubMed1988

[Pulse wave velocity and ambulatory blood pressure in essential arterial hypertension].

Cardiovascular morbidity and mortality of hypertensive patients is mainly related to lesions of large arteries. Arterial distensibility estimated by carotid-femoral pulse wave velocity (PWV) was evaluated in 22 patients with sustained essential hypertension, together with three different methods of blood pressure (BP) measurement: mercury sphygmomanometer, semi-automatic BP recording using the Dinamap apparatus and 24 H ambulatory BP monitoring using the Spacelabs Monitor (5200). Table shows that, while PWV was not correlated with BP measured by mercury sphygmomanometer, it was strongly and positively correlated with BP measured by the other procedures. The best correlation coefficient was noted for the systolic BP measured in the Day Time (7 h-22 h) by the ambulatory method. This study shows that BP Monitoring correlates more strongly than clinic or casual BP with indices of target organ damage. (Table: see text).

Adult↗
PubMed1988

[Pulse pressure and echocardiographic parameters in essential arterial hypertension].

UNLABELLED: We measured systolic, diastolic, mean (MAP) and pulsed (PP) arterial pressures (Dinamap 845 XT), carotid femoral pulse wave velocity (PWV) and cardiac parameters (echocardiography) to evaluate myocardiac mass and indexed cardiac mass to body surface area (IM) in 47 subjects (11 normotensives and 36 with sustained essential hypertension). Hypertensives were allocated between two groups with same age, weight and height, same mean arterial pressure (119.8 +/- 9.1 mmHg, 119.7 +/- 11.9 mmHg, NS) and PWV (11.90 +/- 2.20 m/s, 12.51 +/- 1.83 m/s, NS): group I (22 subjects) with pulsed pressure less than 60 mmHg, group II (14 subjects) with pulsed pressure greater than or equal to 60 mmHg. (Table: see text). Newman-Keuls between group I and group II: p less than 0.01 for cardiac mass and IM, p less than 0.001 for PP. Cardiac mass (p less than 0.01) and indexed mass to body surface area (p less than 0.01) were greater in group II (with pp greater than or equal to 60 mmHg) than in group I. CONCLUSION: arterial hypertension is linked with left ventricular hypertrophy which is increased when pulsed pressure is enhanced. This fact could give evidence of importance of pulsatory work in cardiac consequence of hypertension.

Adult↗
PubMed1987

Duration of action of bisoprolol after cessation of a 4 week treatment and its influence on pulse wave velocity and aortic diameter: a pilot study in hypertensive patients.

A pilot study was performed in hypertensive patients (a) to investigate the duration of blood pressure reduction produced by the new beta blocker bisoprolol (10 mg o.d.) after cessation of a 4 week treatment using non-invasive 24 hour ambulatory blood pressure measurements, (b) to study the effects of the drug on large arteries using non-invasive brachio-radial pulse wave velocity and aortic abdominal diameter measurements 3 hours after the last dose of a 4 week treatment. In comparison with the results obtained before treatment a significant reduction of blood pressure and heart rate was observed up to the 40th hour after treatment was terminated. The finding may be relevant for further evaluation of withdrawal phenomena produced by beta-blocking agents. The antihypertensive effect of bisoprolol was associated with significant decreases in brachio-radial pulse wave velocity (from 10.4 +/- 0.4 to 8.6 +/- 0.4 m s-1) and in aortic abdominal diameter (from 18.2 +/- 1.0 to 17.5 +/- 1.3 mm) indicating an increase in arterial distensibility. Further studies are needed to substantiate these observations and to reveal their mechanisms of action.

Adrenergic beta-Antagonists↗
PubMed1987

[Index of arterial and venous compliance and echocardiographic parameters in essential permanent arterial hypertension].

Forearm venous tone (FVT), carotido-femoral pulse wave velocity (PWV), and left ventricular end diastolic diameter (LVD), left ventricular posterior wall thickness (LVPWT), myocardiac mass (MM), measured by echography were evaluated on 25 subjects with sustained essential hypertension and 30 normotensive subjects with same age and same sex. For the overall population, FVT is positively correlated with LVD (r = 0.45, p less than 0.001), with LVPWT (r = 0.37, p less than 0.01) and with MM (r = 0.55, p less than 0.001). PWV is not correlated with LVD but is positively correlated with LVPWT (r = 0.48, p less than 0.001) and with MM (r = 0.40, p less than 0.01). Stroke volume is positively correlated with FVT (r = 0.42, p less than 0.01), but not with PWV. This study shows that in a population of normals and sustained essential hypertensive subjects: i) indexes of venous compliance are correlated with myocardial thickness, myocardiac mass, left ventricular diameter and stroke volume, while ii) indexes of arterial compliance are only correlated with myocardial thickness. Thus, the modifications of arterial and venous compliance observed in sustained essential hypertension influence cardiac structure and function.

Adult↗
PubMed1987

[Comparison between the ambulatory and occasional determination of the blood pressure].

In this study, we have attempted to determine the link between the occasional measurement of the blood pressure with an Hg sphygmomanometer and the ambulatory pressure, considering different recording periods during the nyctemer. The mean values of the period 8-10 A.M. and more generally of the diurnal period (7 am-10 pm) are close to the values occasionally observed, contrary to the night values and the values of the entire 24 hours. The heart frequency is always well correlated to the mean ambulatory frequency, for the entire period studied. The systolic and mean arterial pressure are also well correlated. On the contrary, there is no meaning when the diurnal period (7 am-10 pm) is reduced to the period of diurnal activity (7 am-7 pm). There is a very strong correlation between the values of the systolic, diastolic, and mean pressures observed during 24 hours and the morning period (8-10 am), giving the impression that this period could be a good reflection of the ambulatory blood pressure of the 24 h.

Adult↗
PubMed1986

Extracellular and interstitial fluid volume in obesity with and without associated systemic hypertension.

Fluid volumes and cardiac and renal hemodynamics were investigated in 44 obese men, 22 with normal blood pressure and 22 with sustained essential hypertension. For the same degree of obesity hypertensive patients had a higher value in extracellular (p less than 0.05) and interstitial fluid (p less than 0.01) volumes than normotensive subjects, while plasma volume, total body water, body cellular water, cardiac output, renal blood flow and glomerular filtration rate were similar. For the same level of blood pressure, the expansion of extracellular and interstitial fluid volume paralleled the degree of obesity. Thus, obese patients with hypertension have an absolute increase in extracellular and interstitial fluid volumes. The increase was related both to the degree of overweight and to the mechanisms of hypertension.

Adult↗
PubMed1985

[The renin-angiotensin system and large arteries in the hypertensive patient].

The large arteries are impaired in uncomplicated, permanent, essential arterial hypertension. The peripheral arteries such as the humeral artery or the common carotid artery have a normal or increased diameter, reduced blood flow and, especially, reduced compliance. Reduction of the arterial compliance reflects an impairment peculiar to the large blood vessels, independent of the pressure. Antihypertensive medicines, for a given drop in pressure, may increase, diminish or not change arterial compliance. This is an important point to be taken into account in relation to cardiovascular morbidity and mortality of treated hypertensives. It has been particularly well studied in the context of inhibitors of the renin-angiotensin system.

Angiotensin-Converting Enzyme Inhibitors↗
PubMedDate not supplied

Influence of gender on the level of pulse pressure: the role of large conduit arteries.

The blood pressure curve may be divided into two components: a steady component represented by the mean arterial pressure, and a pulsatile component represented by the purse pressure. Whether the contribution of either these two components may be different in men and women was not yet investigated. The present study used 24 hours ambulatory brachial blood pressure monitoring and determination of casual carotid and radial pulse pressure by applanation tonometry to investigate 320 subjects (199 men and 121 women) with normal or elevated blood pressure. With ambulatory blood pressure monitoring, there was no gender influence on the mean values of mean and diastolic blood pressure, but men were characterized by a significantly higher systolic and pulse pressure (P < 0.001). In women, pulse pressure was strongly and positively correlated with systolic (and not diastolic) blood pressure. In men, pulse pressure was positively correlated with systolic blood pressure and negatively with diastolic blood pressure (P < 0.001). In the overall population (men plus women), brachial ambulatory pulse pressure was positively correlated with body height and mean arterial pressure (P < 0.001) but the latter correlation was stronger in women. Applanation tonometry indicated that, whereas carotid pulse pressure was identical in men and women, men had a significantly higher radial systolic blood pressure, indicating a gender difference in pressure wave transmission. The study provides evidence that men and women did not differ in terms of mean arterial pressure, but rather in terms of pulse pressure and pressure wave transmission, indicating that large (and not only small) arteries modulate the gender difference in the level of blood pressure. This finding may have important implications for the diagnosis and the clinical management of subjects with hypertension.

Adolescent↗
PubMedDate not supplied

[Comparison of central pulse pressure estimated from pulse wave propagation velocity and carotid pulse pressure measured by applantation tonometry].

BACKGROUND: Pulse pressure (PP) corresponds to the difference between arterial systolic blood pressure and diastolic blood pressure. Central PP seems to be a stronger coronary risk marker than brachial PP. Central PP can be estimated by aortic PP measured non invasively by aplanation tonometry of the carotid artery. The aim of this study was to compare 2 methods of estimation of aortic PP: estimation from Pulse Wave Velocities (PWV) and by aplanation tonometry of the carotid artery. Estimation from PWV is based on the non uniform transmission of the PP i.e. the amplification of PP from the aorta to brachial artery, through arteries of increasing impedance. METHODS: One hundred and fifty one subjects were included, 111 hemodialysis patients and 40 subjects free of cardiovascular treatment or cardiovascular organ damage, recruited in a preventive medicine setting. Central PP was measured by aplanation tonometry of the carotid artery. The following formula was used for the relationship between PP and PWV in the two arterial segments considered for pulse wave travel (waterhammer formula): [formula: see text] Where measurement of brachial PP (PPBr) and PWV at aortic (PWVAo) and brachial (PWVBr) gives an estimation of aortic PP (PPAo estimated). Carotid-femoral PWV was used for PWVAo and carotid-radial PWV was used for PWVBr. The two methods were compared by t-test and according to Bland and Altman's method. RESULTS: In the hemodialysis group (73 males, 44 +/- 12 years old), brachial PP was 56 +/- 15 mm Hg and central PP as measured at the carotid level was 47 +/- 15 mmHg. In the healthy group (29 males, 46 +/- 11 years old), these values were 46 +/- 10 mmHg and 35 +/- 10 mmHg respectively. Compared to carotid artery aplanation tonometry, PPAo estimated was larger than central PP by 2.9 +/- 6.3 mmHg in hemodialysis patients and by 5.4 +/- 6.6 mmHg in the healthy group. The difference was significantly larger in healthy subjects than in hemodialysis patients (p = 0.031). CONCLUSION: The PWV estimated PP is larger than the central PP measured at the carotid level by aplanation tonometry. The difference is larger in cardiovascular event free subjects than in patients on hemodialysis.

Adult↗
PubMedDate not supplied

[Green study: quality of blood pressure measurement by general practitioners].

BACKGROUND: Diagnosis and management of hypertension is based on blood pressure (BP), as measured by auscultatory method. However, the devices are rarely checked making the quality of the measures doubtful. OBJECTIVE: To compare BP measured according to the WHO recommendations using 2 different devices: the mercury or aneroid sphygmomanometer used by the physician and a SECURUS manometer that has been calibrated just before the implementation of the study. METHOD: This is a randomised study performed with 1,336 French general practitioners (GP). Each GP received a calibrated SECURUS before the start of the study and was asked to include 2 treated hypertensive patients and one newly diagnosed patient. BP was measured 3 times with each device at 2 different visits. The devices were used in a random order: the order, at the 1st visit, was always the same for all the patients for a given GP. At the second visit the order of the devices was reversed. Patients were classified as normal (BP < 140/90 mm Hg) or high BP with each device at each visit. RESULTS: 3,992 patients were included in the study (2,751 treated hypertensive patients). SECURUS BP measures were rounded up to 0 or 5 by 69% of the GPs and BPs with their own device by 77% of the GPs. A difference between the 2 devices > 5 mmHg was observed in nearly 10% of the GPs for SBP and 4% of the GPs for DBP. At the second visit, 13% of the treated hypertensive patients and 12% of the newly diagnosed patients and in whom no antihypertensive drug treatment has been introduced were not classified as having normal or high BP value in the same way by the 2 devices. CONCLUSIONS: This study confirms the results of a previous pilot study and emphasises the need of BP measurements respecting the guidelines in clinical practice, because of the possible impact on patient care and related costs.

Aged↗
PubMedDate not supplied

[Antihypertensive efficacy of the combination of captopril 50mg and hydrochlorothiazide 25mg evaluated by ambulatory blood pressure measurement].

The anti-hypertensive effects of the captopril-hydrochlorothiazide combination administered during three months as one single morning dose were evaluated in 51 patients with moderate essential hypertension by means of ambulatory blood pressure recording. At the end of the study, the mean values of arterial blood pressure recorded over 24 hours were significantly lowered: systolic pressure was reduced from 145 +/- 11 to 131 +/- 10 mmHg (P less than 0.001), and diastolic pressure from 88 +/- 5 mmHg to 81 +/- 4 mmHg (P less than 0.001). The same results were recorded during the day (07.00 to 22.00 hours) and during the night (23.00 to 06.00 hours). No change in heart rate was observed.

Adult↗
PubMedDate not supplied

[Comparison between the effects of angiotensin-converting enzyme inhibitors and angiotensin II antagonists].

The renin-angiotensin-aldosterone system (RAAS) plays an important role in blood pressure regulation and fluid and electrolyte homeostasis. Angiotensin converting enzyme inhibitors (ACEI) were the first of the RAAS blocking agents to be widely used in the treatment of hypertension and congestive heart failure. Angiotensin II receptor antagonists, another class of pharmacological blockers of the RAAS, have more recently been shown to be safe and useful in hypertension and perhaps also in heart failure. This review deals with the similarities and differences between these two classes of drugs with particular emphasis on the effects of the drugs on the heart, the blood vessels, the kidney (role of the drugs as nephroprotective), the brain, the hormonal profile and finally the potential adverse effects. The place of angiotensin II antagonists in congestive heart failure remains to be more precisely defined.

Angiotensin II↗