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Biomedical subjects

B Chamontin

Publications and source records attributed to B Chamontin.

At least 55 records · Page 3Linked to original sources

[Course of ischemic risk in treated atheromatous hypertensive patients. The PRIHAM study].

Hypertension is one of the major cardiovascular risk factors. However seldom occurs alone in a patient and the antihypertensive treatment should be taken into account when assessing global cardiovascular status. The PRIHAM study was an open study which enrolled 3,216 hypertensive atheromatous patients who already has had a clinical ischaemic accident. Patients were followed-up for 3 years. The lowering effect on cardiovascular risk, starting from the fifteenth month was confirmed to the end of 36-month study. The effect on blood pressure was observed from the third month. Stabilized blood pressure observed within the first year persisted throughout the three years without tachyphylaxis. It was effective on SBP (-14.4%) and on DBP (-15%) while maintaining a stable heart rate both in the supine position or immediately upon standing or after 3 minutes in the standing position. Amongst diabetic and dyslipidemic patients, an absence of deleterious metabolic effects was noticed, parallel with the effectiveness. Tolerance was globally judged as good or very good by the investigating practitioners and the patients expressed an improvement in their feeling of well-being. In conclusion, from the level of effectiveness obtained and the low incidence of adverse effects, urapidil appears well adapted and easy to manage in a population with a particularly high cardiovascular risk.

Adult↗

Non-invasive ambulatory blood pressure variability and cardiac baroreflex sensitivity.

AIM: The objective of this study was to evaluate the relationship between non-invasive ambulatory blood pressure variability and cardiac baroreflex sensitivity in hypertensive patients. SUBJECTS AND METHODS: Ambulatory blood pressure measurements (15-min intervals for 24 h) and continuous blood pressure measurements (Finapres, 20 min at rest after a 10-min resting period) were performed in 123 untreated hypertensives (resting diastolic blood pressure > or = 90 mmHg; 80 males, 43 females; mean +/- SD age 49 +/- 12 years, range 19-73). Fourier series were used to model 24-h blood pressure profiles (four harmonics). Ambulatory blood pressure variability was assessed by determination of the residuals in each 24-h blood pressure profile (measured minus predicted pressures). Resting blood pressure variability was defined as the SD of the mean Finapres value. Baroreflex sensitivity was evaluated by automatic detection of blood pressure and pulse interval sequences of > or = 3 beats when systolic blood pressure and pulse interval sequences changed in the same direction (increase or decrease: 1 mmHg for systolic blood pressure and 4 ms for RR interval), and was assessed as the slope of the regression line for each sequence. RESULTS: Ambulatory systolic blood pressure variability increased with age (r = 0.28*) and systolic pressure (r = 0.44**). Baroreflex sensitivity (increasing systolic pressure/pulse interval) decreased significantly with age (r = -0.48**) and systolic pressure (r = -0.23**), and was significantly related to increased ambulatory blood pressure variability (r = -0.33**). In a multivariate stepwise analysis the relationship between ambulatory blood pressure variability and baroreflex sensitivity (increasing systolic pressure/pulse interval) was statistically independent of age and systolic pressure (R = 0.55, P<0.001); this relationship was not observed with the corresponding decreasing sequence. CONCLUSIONS: This study shows that in uncomplicated hypertension, ambulatory blood pressure variability is related to baroreflex sensitivity independently of the blood pressure level. This finding has prognostic implications for this non-invasive measurement, which needs to be confirmed by large longitudinal studies.

Adult↗

Renal artery stent placement: long-term results with the Wallstent endoprosthesis.

PURPOSE: To evaluate clinical success and long-term patency of a Wallstent in the renal artery. MATERIALS AND METHODS: Twenty-five Wallstents were placed in 21 patients to treat delayed restenosis after previous balloon angioplasty (n = 13) or inadequate immediate postangioplasty response (n = 8). Indications for angioplasty were hypertension in all patients and renal preservation in seven. Stenosis was atheromatous in 15 patients, involving ostium in seven. RESULTS: Stent placement was successful in all patients. At follow-up angiography (range, 12-60 months), four patients (20%) had stent restenosis. Of these, three had undergone treatment for restenosis after angioplasty and three had ostial lesions. Cumulative primary patency rate was 95%, 85%, and 77% at 7, 9, and 15 months, respectively. Hypertension was cured in three patients and improved in 18. CONCLUSION: Arterial stent placement has good clinical results and high long-term patency rates after conventional renal angiography or delayed restenosis, especially in ostial lesions.

Adult↗

[Arterial blood pressure changes, circadian rhythm and arterial elasticity in hemodialysed patients].

An increased blood pressure variability (BVP) and a loss of nocturnal decline in BP could enhance cardiovascular disease. Peripheral resistances and arterial compliance determine systolic BP. BVP could depend on arterial stiffness. We tested this hypothesis in patients with end-stage renal disease (ERSD) who have arterial elasticity impairment. Twenty one ESRD patients (49.9 +/- 16.7 years) 12 mean and 9 women, undergoing maintenance hemodialysis were studied; 19 had treated hypertension. Ambulatory (ABP) monitoring was performed in all patients: BP was measured every 15 minutes in day-time and every 30 minutes at night. Systolic diurnal variation coefficient was calculated as the ratio between standard deviation and the mean of systolic diurnal BP. Nycthemeral BP pattern was evaluated as the ratio between mean diurnal and nocturnal systolic BP (N/D). Pulse wave velocity (PVW), an index of arterial stiffness, was determined between carotid and femoral sites (11.6 +/- 4.22 m/s). These investigations were performed after the midweek dialysis session. We found a positive correlation between PVW and systolic diurnal BPV (stepwise regression F = 12.9, p < 0.01). This correlation was independent of hypertension, antihypertensive treatment, duration of hemodialysis, and erythropoientin. We also found a positive correlation between N/D and PWV (stepwise regression: F = 8.9 p < 0.05). Our study shows that arterial distensibility links BPV and N/D. It is suggested that an arterial distensibility impairment could enhance BPV and modify nycthemeral BP pattern.

Adult↗

[Ambulatory measurement of blood pressure and plasma catecholamines in the study of orthostatic hypotension].

The purpose of the study was to investigate the interest of ambulatory blood pressure (BP) monitoring (ABPM) and plasma catecholamines in the management of orthostatic hypotension (OH). Fifteen patients, 4 men, 11 females, 53.3 +/- 21.1 years old, with OH were included in the study: 7 with dysautonomia (G1) = multiple systemic atrophy, pure autonomic failure, OH in elderly people; 8 with OH from other origin (G2) = hypovolemia, neurodystonia, vaso-vagal syncope. ABPM and plasma catecholamines assays (HPLC) in lying then in standing position were carried out in all patients. BP was 131.2 +/- 31.9/78.1 +/- 12.0 mmHg in lying and 112.1 +/- 25.3/75.4 +/- 15.8 in standing position (n = 15). The systolic (S) standing-induced (delta) decrease in BP after 1 min and 10 min (delta SBP) correlated with standard-deviation and variation coefficient of mean SBP (r = 0.78, p < 0.01; r = 0.82, p < 0.01 for delta sBP 1 min and r = 0.80, p < 0.01; r = 0.81, p < 0.01 for delta sBP 10 min), but not with norepinephrine (NorE) or epinephrine levels. There was a significant correlation between diastolic nycthemeral BP variability expressed by mean night-time DBP/mean day-time DBP ratio/diastolic N/D) and standing-induced decrease in DBP after 1 min (r = 0.59, p < 0.05). delta SBP 1 min and 10 min, delta DBP 1 min (p = 0.02, p = 0.05, p = 0.01) and systolic and diastolic N/D (p = 0.02; p < 0.01) were significantly different in G1 and G2.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Blood pressure measurements and left ventricular mass in young adults with arterial hypertension screened at high school check-up.

The aim of this study was to determine which BP measurement is the best related to target organ damage. There were 49 young adults with a history of childhood hypertension (school check-up) and to increase the prevalence of hypertension in the study group, 25 males 24 females, aged 20.1 +/- 2.2 years old were included in the study. All patients had a diurnal ambulatory BP monitoring and office BP measurements taken with a sphygmomanometer and with an oscillometric device during a 15 minute period monitoring (Dinamap BP). Echocardiography and blood samples (cholesterol and triglycerides) were performed in all patients. In contrast with office BP, a mean ambulatory SBP and mean Dinamap SBP significantly correlated to left ventricular mass index (LVMI) (P < 0.01). There was also a correlation between triglycerides and mean Dinamap SBP (P < 0.01) which could suggest an early insulin resistance. In this selected population, a short period BP monitoring, as well as ambulatory BP, is more closely related to LVMI than office BP.

Adolescent↗

[Rheumatologic aspects of toxocariasis (visceral Larva migrans). Apropos of 2 cases].

Visceral Larva migrans is a human infection by the larvae of dog ascarids or, more rarely, ascarids of other animal species. It is endemic in France. Two cases which respectively manifested as acute oligoarthritis and inflammatory myalgia with increased muscle enzyme levels are reported. Manifestations of the minor forms of this infestation are reviewed.

Adult↗

[Ambulatory monitoring of blood pressure in orthostatic hypotension of Parkinson disease].

Ambulatory recordings of blood pressure (BP) and heart rate were performed using a Spacelabs device during day and night periods in parkinsonian patients with (n = 19) or without (n = 19) orthostatic hypotension. In patients with orthostatic hypotension, the average blood pressure during the night (systolic BP: 137 +/- 5 mmHg; diastolic BP: 80 +/- 3 mmHg) was higher (p < 0.05) than during the diurnal period (systolic BP: 121 +/- 3 mmHg; diastolic BP: 76 +/- 2 mmHg). In parkinsonian patients without orthostatic hypotension, a physiological decrease in BP was recorded during the nocturnal period. In patients with orthostatic hypotension, BP variability was higher (p < 0.05) during the day (systolic BP: 14.6 +/- 1.3%, diastolic BP: 16.5 +/- 1.0%) than during the night (systolic BP: 9.1 +/- 0.8%, diastolic BP: 10.8 +/- 1.1%). The blood pressure load (% of BP values above 140/90 mmHg) during the night was significantly higher (p < 0.05) than during the day for both systolic (41.2 +/- 8.1 vs 19.6 +/- 4.7%) and diastolic BP (24.9 +/- 6.9 vs 16.3 +/- 4.9%). A normal decrease in heart rate was found in both groups during the night. A fall of at least 25 mmHg in systolic BP after meals occurred in 10 patients with orthostatic hypotension and in 1 without orthostatic hypotension. These results indicate that orthostatic hypotension in Parkinson's disease is associated with specific modifications of ambulatory blood pressure including loss of circadian rhythm of BP, increased diurnal BP variability and often post-prandial hypotension.

Aged↗

[For which hypertensive patient should angiotensin-converting enzyme inhibitor be prescribed or forbidden?].

Angiotensin-converting enzyme (ACE) inhibitors act by lowering the level of angiotensin II. The therapeutic benefits of these drugs and their potential side-effects therefore result from suppression of the physiological effects of angiotensin II. It is rational to prescribe an ACE inhibitor when the renin-angiotensin system is activated, as in renin-dependent essential hypertension, malignant hypertension and hypertension associated with heart failure. The beneficial effects of ACE inhibitor must be weighed against the special risks of renovascular hypertension: risk of renal artery thrombosis in case of unilateral stenosis and risk of renal failure if the stenosis is bilateral or affects a solitary kidney. In some situations the renin-angiotensin system is not directly involved in hypertension but may play a local haemodynamic role, as in some cases of primary or diabetic nephropathy. In such case the ACE inhibitors are thought to exert a protective effect. ACE inhibitors were reputed to be less effective in the elderly than in younger patients, but we now know that they can be prescribed with equal success in both instances to reduce peripheral resistance and improve regional blood flow as well as arterial compliance. Finally, ACE inhibitors can be prescribed, albeit with limited effectiveness, when the renin-angiotensin system is not activated, as in low renin hypertension and idiopathic hyperaldosteronism due to adrenal hyperplasia. They are ineffective in case of Conn's adenoma and contra-indicated in pregnant women.

Angiotensin-Converting Enzyme Inhibitors↗

Ambulatory blood pressure in patients with Parkinson's disease without and with orthostatic hypotension.

Non-invasive ambulatory recordings of blood pressure and heart rate were performed using a Spacelabs device during day and night periods in patients with Parkinson's disease with (n = 19) or without orthostatic hypotension (n = 19). In patients with orthostatic hypotension, the average systolic and diastolic blood pressure during the night (137 +/- 5/80 +/- 3 mmHg) was higher (p less than 0.05) than during the day period (121 +/- 3/76 +/- 2 mmHg). In patients without orthostatic hypotension, a decrease in blood pressure was recorded during the nocturnal period. In patients with orthostatic hypotension, the blood pressure variability was higher (p less than 0.05) during the day (systolic: 14.6 +/- 1.3%; diastolic: 16.5 +/- 1.0%) than during the night (systolic: 9.1 +/- 0.8%; diastolic: 10.8 +/- 1.1%). The blood pressure load (percentage of values above 140/90 mmHg) during the night was significantly higher than during the day for both systolic (41.2 +/- 8.1 vs. 19.6 +/- 4.7%) and diastolic blood pressure (24.9 +/- 6.9 vs. 16.3 +/- 4.9%). There was a decrease in heart rate in both groups during the night. A fall of 25 mmHg or more in systolic blood pressure after meals occurred in ten patients with orthostatic hypotension and in one patient without orthostatic hypotension. These results indicate that orthostatic hypotension in Parkinson's disease is associated with specific modifications of ambulatory blood pressure including loss of circadian rhythm of blood pressure, increased diurnal blood pressure variability and post-prandial hypotension.

Aged↗

[Value of nocturnal blood pressure in treated non-insulin-dependent hypertensive patients].

The purpose of the study was to evaluate the loss of nocturnal (N) decline in blood pressure (BP) in type II treated hypertensive diabetics. The study concerned 36 hypertensive diabetics 59 +/- 10 years old, 20 men and 16 women, with poor metabolic control (HbA1C: 9.6 +/- 3%), without dysautonomia; 14 had macroproteinuria and/or microalbuminuria (mu alb) (< 30 micrograms/min). An ambulatory BP monitoring (Spacelabs 90207) was performed in all patients. Left ventricular mass index (LVMI) and E/A were determined by Doppler-echocardiography. Two groups (G) were individualized: G1 (n = 17), with a normal circadian rhythm (diurnal and N.BP significantly different); G2 (n = 19) with a loss of N decline in systolic (S) and diastolic (D) BP or both; and compared to non diabetic treated hypertensive controls (G3). There was no difference neither in LVMI (125 +/- 43 g/m2), E/A (0.7), 24 h-mean (M) BP in the three groups, nor in HbA1C levels and mu alb occurrence in G1 and G2. Mean N.SBP and mean N.DBP were more closely related to LVMI in G2 than in G1 and G3. [table: see text] Half of these hypertensive diabetics, with bad metabolic control, have an altered circadian BP pattern; the prognostic value of nocturnal BP, related to LVMI despite the antihypertensive treatment, is suggested.

Aged↗

[Value of the study of electrocardiographic P wave in pheochromocytoma].

The diagnostic value of electrocardiographic P wave analysis in the frontal plane was assessed with respect to previously reported abnormalities: right atrial hypertrophy-dilatation; an enlarged, crenalleted summit without criteria of right atrial hypertrophy. Two observers studied the ECG recordings of 20 hypertensive patients with pheochromocytomas: 10 men and 10 women, aged 45.5 +/- 16 years, and in 30 patients with essential hypertension, 15 men and 15 women, aged 48.9 +/- 9 years (NS). The duration of hypertension was 2.6 +/- 2 years versus 4.7 +/- 4 years (p = 0.02). Right atrial hypertrophy-dilatation was observed in 5 patients in the pheochromocytoma group and in none of the essential hypertensive patients: an isolated abnormality of the summit of the P wave was observed in 5 other cases of pheochromocytoma and by 1 observer in 1 of the essential hypertension. These abnormalities disappeared after ablation of the tumour. These changes were not recorded in 3 patients who had predominant noradrenaline hypersecretion; nevertheless, comparison of the urinary adrenaline, noradrenaline, normeta- and metanephrine levels were inconclusive. No relationship was established between these concentrations, global urinary catecholamines and meta block, the duration of hypertension, the frequency and level of hypertensive crises, or the presence of "ischaemic" ST-T wave changes. P wave changes are thought to be related to high plasma catecholamine levels irrespective of the clinical impact; the sensitivity of these changes is modest (10/20) but the specificity is better within a group of hypertensive patients. An experienced observer can orient the diagnostic investigations to the search for a pheochromocytoma or to a secondary recurrence of the tumour from the surface ECG. The role of marker of a very high noradrenaline or adrenaline secretion cannot be confirmed from a series limited in separated plasma concentration measurements.

Adrenal Gland Neoplasms↗

[Results of the evaluation of platelet sodium-proton exchange in the young hypertensive subject].

In order to assess the relationships between increased cellular sodium-proton (Na+/H+) exchange and cardiovascular abnormalities in essential hypertension (EH), 21 young subjects as part of an ongoing longitudinal study were tested for the platelets Na+/H+ exchange using the amiloride sensitive sodium dependent component of platelet volume change under cytoplasmic acidification induced by a sodium propionate medium; cell volumes were determined by electronic cell sizing (Livne et al., Lancet 1987; i: 533-6). 24 normal subjects with normotension and without familial history of hypertension were taken as controls. Data of ambulatory blood pressure recording (ABPR) defined 2 groups according to the presence of normotension (group I, n = 10), or of hypertension (group II, n = 11): established (n = 2) or borderline (n = 9) hypertension. Hypertensive subjects (group II) had increased values of Na+/H+ exchange (k coefficient, mean (SEM): 0.287 (0.07) vs 0.228 (0.05) in control group (p less than 0.01). Na+/H+ rates were significantly related to ABPR data (r = 0.46, p less than 0.02 with diastolic charge during ABPR), but not to left ventricular mass index in g/m2 by echocardiography. Increased rates of platelets Na+/H+ exchange which were related to diastolic blood pressure levels by ABPR, and perhaps to the level of peripheric vascular resistances, may play a significant role in the development of EH in the early stages.

Adolescent↗