[Antihypertensive agents used as first line agents: beta-blockers under pressure].
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Biomedical subjects
Publications and source records attributed to B Waeber.
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The diagnosis and the treatment of hypertension are based on blood pressure readings traditionally taken at the level of the brachial artery. It is currently possible to determine central blood pressure using the aplanation tonometry technique and applying a transfer function to calculate the impact of reflecting waves on pressure prevailing in thoracic aorta. The reflected waves which reach the thoracic aorta in systole are more marked when the stiffness of the arterial wall is increased, leading to augmentation of central systolic blood pressure. Recent clinical trials have shown that, for the same decrease in peripheral blood pressure, different therapeutic strategies do not necessarily impact identically on central blood pressure. This fact might influence their ability to prevent cardiovascular complications.
Aldosterone plays a pivotal role in sodium and water homeostasis, in particular in patients with heart failure or high blood pressure. These medications, when used on top of a standard therapy, improve the outcome of patients with heart failure and are also effective in lowering blood pressure of hypertensive patients. The major risk associated with the use of these antagonists is hyperkalemia, which can be prevented in avoiding their prescription in patients with impaired renal function. Eplerenone has the advantage, compared with spironolactone, to be better tolerated in terms of "hormonal" adverse effects.
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The Raynaud's phenomenon seems to be well known among the health care workers. It has been identified a long time ago, as Maurice Raynaud described the phenomenon which bears his name in 1862. However its true definition is often forgotten. Moreover the Raynaud's phenomenon is easily confounded with other entities like acrocyanosis... The topic of this review has firstly been chosen in order to precise the criteria of the Raynaud's phenomenon, secondly to mention the new pathogenic aspects recently described and the new therapeutic interventions developed in this field.
There is no doubt today that hypertensive therapy is effective in preventing cardiovascular complications. Having blood pressures 140/190 mmHg repeatedly at the doctor's office is associated with an increased cardiovascular risk and requires drug treatment if non-pharmacological measures do not allow blood pressure normalization. Antihypertensive therapy might already be required in patients exhibiting simultaneously blood pressure > or = 130/180 mmHg and diabetes and/or renal disease.
The following is a brief statement of the 2003 European Society of Hypertension (ESH)-European Society of Cardiology (ESC) guidelines for the management of arterial hypertension. The continuous relationship between the level of blood pressure and cardiovascular risk makes the definition of hypertension arbitrary. Since risk factors cluster in hypertensive individuals, risk stratification should be made and decision about the management should not be based on blood pressure alone, but also according to the presence or absence of other risk factors, target organ damage, diabetes, and cardiovascular or renal damage, as well as on other aspects of the patient's personal, medical and social situation. Blood pressure values measured in the doctor's office or the clinic should commonly be used as reference. Ambulatory blood pressure monitoring may have clinical value, when considerable variability of office blood pressure is found over the same or different visits, high office blood pressure is measured in subjects otherwise at low global cardiovascular risk, there is marked discrepancy between blood pressure values measured in the office and at home, resistance to drug treatment is suspected, or research is involved. Secondary hypertension should always be investigated. The primary goal of treatment of patient with high blood pressure is to achieve the maximum reduction in long-term total risk of cardiovascular morbidity and mortality. This requires treatment of all the reversible factors identified, including smoking, dislipidemia, or diabetes, and the appropriate management of associated clinical conditions, as well as treatment of the raised blood pressure per se. On the basis of current evidence from trials, it can be recommended that blood pressure, both systolic and diastolic, be intensively lowered at least below 140/90 mmHg and to definitely lower values, if tolerated, in all hypertensive patients, and below 130/80 mmHg in diabetics. Lifestyle measures should be instituted whenever appropriate in all patients, including subjects with high normal blood pressure and patients who require drug treatment. The purpose is to lower blood pressure and to control other risk factors and clinical conditions present. In most, if not all, hypertensive patients, therapy should be started gradually, and target blood pressure achieved progressively through several weeks. To reach target blood pressure, it is likely that a large proportion of patients will require combination therapy with more than one agent. The main benefits of antihypertensive therapy are due to lowering of blood pressure per se. There is also evidence that specific drug classes may differ in some effect or in special groups of patients. The choice of drugs will be influenced by many factors, including previous experience of the patient with antihypertensive agents, cost of drugs, risk profile, presence or absence of target organ damage, clinical cardiovascular or renal disease or diabetes, patient's preference.
INTRODUCTION: The aim of this study was to assess the blood flow in the feet before and after lower limb revascularization using laser Doppler imaging (LDI). METHODS: Ten patients with critical lower limb ischemia were prospectively enrolled from June to October 2004. All patients underwent successful unilateral surgical interventions including above-knee bypass, distal bypass and endarterectomy. Skin blood flow (SBF) over the plantar surface of both forefeet and heels was measured by LDI 24h before and 10 days after revascularization, expressed in perfusion units (PU), and reported as mean+/-SD. RESULTS: Measurements in the forefoot and heel were similar. Before revascularization mean SBF was significantly lower in the ischemic foot (130+/-71 PU) compared to the contralateral foot (212+/-68 PU), p<0.05. After revascularization a significant increase of the SBF in the forefoot (from 135+/-67 to 202+/-86 PU, p=0.001) and hindfoot (from 148+/-58 to 203+/-83, p=0.001) was observed on the treatment side. However, a large decrease of the SBF was seen in forefoot and hindfoot on the untreated side (from 250+/-123 PU to 176+/-83 and from 208+/-116 to 133+/-40, p=0.001, respectively). CONCLUSION: This study confirms the benefits of revascularization in patients with nonhealing foot lesions due to critical limb ischemia. A significant increase of the SBF was observed on the treatment side. However, an unexpected decrease was observed on the untreated side.
In approximately 10% of adults, ambulatory blood pressures recorded during everyday activities or selfmeasured blood pressures are abnormally elevated whereas office blood pressures are in a normal range. This type of blood pressure behavior, known as masked hypertension, is associated with an increased cardiovascular risk. It may be pertinent to search for the presence of masked hypertension in individuals having sometimes elevated, sometimes normal office blood pressures, as well as in very high risk patients and in patients requiring an optimal blood pressure control, such as for instance in those with diabetes or nephropathy.
Blood pressure is abnormally elevated in acute stroke in most patients. This blood pressure increase is usually transient and associated with a poor prognosis. Lowering blood pressure too importantly during this period may worsen the outcome of the patient. Antihypertensive therapy is therefore required only when blood pressure is severely increased, especially in the presence of intracerebral haemorrhage. Initiating treatment before admission to the hospital is not recommended. The medications to be preferred are the blockers of the renin-angiotensin system, the beta-blocker labetalol (which possesses also alpha-blocking properties) and NO donors.
Peroxynitrite is a potent oxidant and nitrating species proposed as a direct effector of myocardial damage in a wide range of cardiac diseases. Whether peroxynitrite also acts indirectly, by modulating cell signal transduction pathways in the myocardium, has not been investigated. Here, we examined the ability of peroxynitrite to activate extracellular signal-related kinase (ERK), a MAP kinase which has been linked with hypertrophic and anti-apoptotic responses in the heart, in cultured H9C2 cardiomyocytes. Peroxynitrite elicited a concentration- and time-dependent activation of ERK, secondary to the upstream activation of MEK 1 (ERK kinase). Activation of MEK-ERK by peroxynitrite was related to the upstream activation of Raf-1 kinase, as ERK and MEK phosphorylation were prevented by the Raf-1 inhibitor BAY43-9006. These effects of peroxynitrite were not associated with the activation of p21(Ras), known as a common signaling target of cellular oxidative stress. In contrast to ERK activation mediated by the epidermal growth factor (EGF), ERK activation by peroxynitrite was not prevented by AG1478 (EGF receptor inhibitor). Peroxynitrite acted through oxidative, but not nitrative chemistry, as ERK remained activated while nitration was prevented by the flavanol epicatechin. In addition to ERK, peroxynitrite also potently activated two additional members of the MAP kinase family of signaling proteins, JNK and p38. Thus, peroxynitrite activates ERK in cardiomyocytes through an unusual signaling cascade involving Raf-1 and MEK 1, independently from EGFR and P21(Ras), and also acts as a potent activator of JNK and p38. These results provide the novel concept that peroxynitrite may represent a previously unrecognized signaling molecule in various cardiac pathologies.
AIMS: The plasma levels of either brain natriuretic peptide (BNP) or the N-terminal fragment of the prohormone (NT-proBNP) have recently gained extreme importance as markers of myocardial dysfunction. Patients with type 2 diabetes are at high risk of developing cardiovascular complications. This study was aimed to assess whether plasma NT-proBNP levels are at similar levels in type 2 diabetics with or without overt cardiovascular diseases. METHODS: We assayed plasma NT-proBNP in 54 type 2 diabetics, 27 of whom had no overt macro- and/or microvascular complications, while the remaining ones had either or both. The same assay was carried out in 38 healthy control subjects age and sex matched as a group with the diabetics. RESULTS: Plasma NT-proBNP was higher in diabetics (median 121 pg/ml, interquartile range 50-240 pg/ml, ) than in those without complications (37 pg/ml, 21-54 pg/ml, P<0.01). Compared with the controls (55 pg/ml, 40-79 pg/ml), only diabetics with vascular complications had significantly increased plasma NT-proBNP levels (P<0.001). In the diabetics, coronary heart disease and nephropathy (defined according to urinary excretion of albumin) were each independently associated with elevated values of plasma NT-proBNP. CONCLUSIONS: In type 2 diabetes mellitus, patients with macro- and/or micro-vascular complications exhibit an elevation of plasma NT-proBNP levels compared to corresponding patients with no evidence of vascular disease. The excessive secretion of this peptide is independently associated with coronary artery disease and overt nephropathy. The measurement of circulating NT-proBNP concentration may therefore be useful to screen for the presence of macro- and/or microvascular disease.
Effective treatment of hypertension is essential to reduce the risk of renal and cardiovascular (CV) morbidity. The risks associated with hypertension are modulated by the presence of other factors. This has prompted the quest for agents that have benefits beyond blood pressure (BP) lowering. The angiotensin II receptor blocker (ARB) class of antihypertensive agents represents an important addition to the therapeutic options for elevated BP. Their ability to control BP is equivalent to existing therapies and there is a considerable and mounting evidence-base for their ability to reduce hypertension-associated target organ damage and comorbidities. Studies show that ARBs have clinical benefits across the spectrum of disease severity. In particular, recent large studies have demonstrated that these benefits extend to patients with conditions predisposing to CV events, such as diabetes, left ventricular hypertrophy and microalbuminuria, and where risk factors coexist. Data from these studies suggest that the CV protective effects of ARBs are at least, in part, independent from the BP lowering action. In addition, ARBs are extremely well tolerated, and strong evidence suggests that compliance with therapy--a key factor in achieving adequate BP control--with ARBs is higher than with other antihypertensive agents. Furthermore, flexible dosing and good tolerability profile mean that, where necessary, ARBs can be combined with other classes of antihypertensive agents to achieve adequate BP control and reduce the risk of hypertension-associated morbidity.
Treatment of hypertension remains a difficult task despite the availability of different types of medications lowering blood pressure by different mechanisms. In order to reach the target blood pressures recommended today combination therapy is required in most patients. The co-administration of two drugs with different impacts on the cardiovascular system markedly increases the antihypertensive effectiveness without altering adversely tolerability. Fixed low-dose combinations are becoming a valuable option not only as second-line, but also as first-line therapy. In this respect the co-administration of thiazide diuretic with an AT(1)-receptor blocker is particularly appealing. The diuretic-induced decrease in total body sodium activates the renin-angiotensin system, thus rendering blood pressure maintenance angiotensin II-dependent. During blockade of the renin-angiotensin system low doses of thiazides generally suffice, allowing the prevention of undesirable metabolic effects. Also, blockade of the AT(1)-receptor, particularly when angiotensin II production is enhanced in response to diuretic therapy, is expected to be beneficial, since angiotensin II seems to contribute importantly to the pathogenesis of cardiovascular and renal complications of hypertension.
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During their first two years at the medical faculty of the University of Lausanne, selection of medical students is based on their performance in tests in basic sciences. However, this carries the risk that scientifically talented students who perhaps do not necessarily possess the personal skills to make them a good doctor are given preferential admission to the clinical semesters. This study followed a student cohort (n = 115), which had passed the first part of their state examination at the end of the third year course. The examination included an oral examination in psychosocial medicine (PSM) that tested the student's skills with regard to patient-physician communication. The PSM grade is compared with the grade achieved in the written tests in physics and physiology taken at the end of the first year of study. The findings showed that the performance achieved in the basic science examination had no predicative value for the student's future performance in the PSM test. Moreover, it was found that the type of pre-graduate degree had no major influence on the student's progress in their preclinical years of medical school.
OBJECTIVE: The present study was undertaken to assess in pre- and postmenopausal women whether obesity influences cutaneous reactive hyperemia in the forearm. DESIGN: Cross-sectional study. SUBJECTS AND METHODS: Eight lean premenopausal (age 24.6+/-3.5 y, BMI=21.9+/-1.5 kg/m(2), mean+/-1 s.d.), eight obese premenopausal (age 27.8+/-5.1 y, BMI=35.3+/-5.8 kg/m(2)), eight lean postmenopausal (age 56.1+/-8.3 y, BMI=20.2+/-2.2 kg/m(2)) and eight obese postmenopausal women (age 57.4+/-6.1 y, BMI=32.8+/-3 kg/m(2)) were included. Plasma glucose, insulin and lipid profile were determined in fasting state, and a glucose tolerance test was performed. The skin blood flow response to transient occlusion of the forearm circulation (reactive hyperemia, RH) was measured using a laser-Doppler imaging system. RESULTS: Obese women had hyperinsulinemia, suggesting that they were insulin-resistant. The magnitude of the RH was similar in postmenopausal compared to premenopausal women. Obesity did not influence this microvascular response. CONCLUSION: Obesity, which is known to be associated with impaired endothelial-dependent vasodilation in the skeletal musculature, has no effect on the RH of the forearm skin microcirculation.
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