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Query: UMLS:C0085580 (essential hypertension)
 14,686 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Over the last decade, a great body of evidence has pointed towards the role of kidneys in the genesis and maintenance of a hypertensive state. There exists a relationship between a rise in the blood pressure and a proportionate increase in the urinary excretion of sodium and water called the pressure-natriuresis curve. Chronic renal diseases are the most common causes of secondary hypertension accounting for 2-5% of all cases of secondary hypertension. The prevalence rate of renovascular hypertension based upon referral patterns range from 0.2% to 10% of hypertensive population. The data provided by the International Registries on end-stage renal disease have suggested that essential hypertension is an important cause of progressive renal damage. The pathological lesion observed in malignant hypertension is fibrinoid necrosis of the small arteries and arterioles. Amongst the armamentarium of antihypertensive drugs calcium channel antagonists and the angiotensin converting enzyme inhibitors have a role in limiting glomerular hypertension. The best modality to prevent and treat renal dysfunction in the presence of hypertension is an adequate and effective control of high blood pressure.
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PMID:Hypertension and the kidneys--inter-relationship and therapeutic approach. 1065 8

Sera from patients with malignant essential hypertension (n = 14), malignant secondary hypertension mainly attributable to renovascular diseases (n = 12) and renovascular diseases without malignant hypertension (n = 11) and from normotensive healthy blood donors (n = 35) were studied for the presence of autoantibodies against G-protein-coupled cardiovascular receptors. Autoantibodies against the angiotensin II receptor (AT1) were detected in 14, 33, 18 and 14% of patients with malignant essential hypertension, malignant secondary hypertension, renovascular diseases and control patients, respectively. Sensitivity of the enzyme immunoassay was assessed as 5 microg/ml IgG. Patients did not show antibodies against bradykinin (B2) or angiotensin II subtype 2 (AT2) receptors. Autoantibodies affinity-purified from positive patients localized AT receptors in Chinese hamster ovary transfected cells, and displayed a positive chronotropic effect on cultured neonatal rat cardiomyocytes. These results demonstrate the existence of autoantibodies against a functional extracellular domain of human AT1 receptors in patients with malignant hypertension, and suggest that these autoantibodies might be involved in the pathogenesis of malignant hypertension.
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PMID:Autoantibodies against the angiotensin receptor (AT1) in patients with hypertension. 1093 Jan 93

This article discusses the pathophysiologic features, diagnosis, treatment, and management of patients with renovascular hypertension. Timely diagnosis is important as the disease can carry a more serious prognosis than essential hypertension and is less amenable to drug treatment. Renovascular hypertension also carries a greater risk of progression to accelerated or malignant hypertension and may result in irreversible ischemic failure of the affected kidney. Various treatments are available including medical management, angioplasty and/or stenting, and revascularization. Regardless of treatment approach, nursing care is an integral part of the patient's management, especially continuing follow-up of blood pressure.
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PMID:Renovascular hypertension. 1141 67

To investigate the hypothesis that abnormalities of thrombogenesis and endothelial damage/dysfunction are greater in malignant hypertension (MHT) compared with uncomplicated nonmalignant essential hypertension (EHT) > 160/90 mm Hg), we measured markers of endothelial function (von Willebrand factor) platelet activation (soluble P-selectin) and fibrinogen in 18 consecutive patients with MHT, 50 patients with untreated EHT, and 34 healthy control subjects. We also investigated whether there was any diurnal variation in the measured indices, as well as the effects of good blood pressure (BP) control after 6-month follow-up. Mean plasma fibrinogen and von Willebrand factor levels were both highest in the MHT group, intermediate in the nonmalignant hypertension group and lowest in the normotensive control subjects (P < .001). Similarly, mean soluble P-selectin levels were higher in both hypertensive groups compared to normotensive control subjects (P = .033). There was no significant diurnal variation in plasma fibrinogen, soluble P-selectin, and von Willebrand factor levels over the 24-h study period among the MHT patients. At 6-month follow-up and a reduction in mean BP, there was no significant change in mean plasma fibrinogen levels (P = .25), but both soluble P-selectin (P < .001) and von Willebrand factor (P = .0025) were significantly reduced. In conclusion, malignant hypertension is associated with abnormal endothelial damage (elevated von Willebrand factor), platelet activation (soluble P-selectin), and fibrinogen levels, which may be related to the pathogenesis of this condition, as well as the development of complications. These abnormalities do not undergo any significant diurnal variation and may be beneficially altered by BP reduction.
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PMID:A cross-sectional, diurnal, and follow-up study of platelet activation and endothelial dysfunction in malignant phase hypertension. 1149 1

The aim of the present study is to investigate the pathophysiological characteristics of a number of recent cases of malignant hypertension (MHT) and to compare them to the characteristics of earlier cases. Patients with MHT (age 25-76, mean 44+/-2 years) who were admitted to our hospital from 1984-1999 were retrospectively studied. All of the patients had either grade III or IV retinopathy and diastolic blood pressure levels higher than 120 mmHg. The observations in this study were compared to previously reported findings regarding 59 MHT patients who were admitted from 1971-1983. Of the 37 recent MHT patients, 20 had essential hypertension (EHT) as the underlying disease, 13 had chronic glomerulonephritis (CGN), and the remaining 4 presented with other diseases including pyelonephritis and renovascular hypertension. A positive family history of hypertension was more prevalent in the EHT patients than in other patients, and persistent proteinuria, microhematuria, and anemia were more prevalent in the CGN patients. These characteristics were similar between the recent and previous cases. Within 4 weeks after admission, hemodialysis was initiated in 3 of the 13 patients (23%) with CGN and 2 of the 20 (10%) patients with EHT. The prevalence of renal death at 1 year after admission was 30%, which was lower than the prevalence in the previous cases (42%). Grade IV retinopathy was seen in 45% of the patients admitted from 1984-1999, significantly less than in the patients admitted from 1971-1983 (66%, p<0.05). In addition, left ventricular hypertrophy was less frequently observed on electrocardiogram in the recent cases (67%) than in the previous cases (88%, p<0.05). Our results suggest that the recent cases of MHT demonstrate less severe organ damage.
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PMID:Trends in the pathophysiological characteristics of malignant hypertension. 1167 41

The purpose of this study was to evaluate the utility of computed tomography (CT) renal angiogram (CTRA) in the management of childhood hypertension. This is a retrospective study of 24 children with clinical suspicion of renovascular disease who underwent CTRA examinations. CTRA demonstrated surgically correctable etiology of hypertension in 38% of the patients [5 with renal artery stenosis (RAS) and 4 with renal pathology]. In 5 patients, CTRA findings of RAS were confirmed by catheter angiogram. CTRA missed RAS in 1 patient in whom catheter angiogram showed beaded narrowing of the renal artery. All 6 patients with RAS had resolution of hypertension immediately after angioplasty or surgery. One patient with diffuse renal artery stenosis had an ipsilateral multicystic dysplastic kidney. In this patient hypertension resolved spontaneously as the dysplastic kidney shrunk in size. Seven patients had a renal etiology for hypertension. In 3 of these patients hypertension resolved after nephrectomy. Malignant hypertension in the 4th patient with reflux nephropathy was controlled medically after she underwent bilateral ureteral reimplantation. The remaining 3 patients with renal etiology were managed medically. We found that the etiology was central for hypertension in 4 patients with brain abnormalities, obesity in 1 overweight patient, essential hypertension in 4 patients, and thoracic aorta coarctation in 1 patient. Our study showed that in all except 1 instance CTRA could diagnose a surgically correctable cause for hypertension. CTRA provided useful information for the management of pediatric hypertension in all our patients.
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PMID:Utility of computed tomographic renal angiogram in the management of childhood hypertension. 1221 28

Large prospective epidemiologic studies have shown that long-term use of oral contraceptives containing estrogen induce an increase in blood pressure and sharply increase the risk of hypertension. Susceptibility to the hypertensive effects of oral contraceptives is heightened where risk factors such as age, family history of hypertension, preexisting or occult renal disease, parity and obesity exist. Hypertension among pill users usually develops within the first 6 months of usage and occasionally is delayed for as long as 6 years. Anitihypertensive therapy is seldom needed as the hypertension that developes is generally mild and uncomplicated, and rapidly reverses when the pills are discontinued. However, a small percentage of patients develop severe, even life-threatening hypertension and the hypertensive effects are felt long after the pills are discontinued. Cases of malignant hypertension and irreversible renal failure requiring maintenance hemodialysis, bilateral nephrectomy, and renal transplantation have occurred following administration of oral contraceptive pills. The mechanism by which oral pills induce hypertension in susceptible women is not known and needs further research. Before oral contraceptives are prescribed, physicians should take a careful history and perform a detailed physicial examination with special attention to the cardiovascular system. Multiple blood pressure measurements should be made and routine laboratory studies including urinalysis, blood urea and nitrogen and serum creatinine should be performed. It is preferable to start with a relatively low (50 mcg) estrogenic content preparation. Patients who develop hypertension (diastolic pressure, 90 mm Hg) on oral contraceptives should stop taking the pills immediately, and should be considered to have estrogen-induced hypertension. They should never again receive estrogen-containing oral pills, although they can try pills containing only progestogen. There is no contraindication to pregnancy in these patients, as most women who become hypertensive on oral pills go on to have normotensive pregnancies. Pregnancy in women who are susceptible to essential hypertension however should be treated as high risk.
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PMID:Hypertension and oral contraceptives. 1226 83

Malignant hypertension is a rare but serious syndrome complicating 1% of essential hypertension and causing neurological, renal and cardiac complications. Despite improved anti-hypertensive medication, the incidence of this condition fails to decline. In the first part of this review, we discuss transgenic rat models of malignant hypertension, generated by over-expressing renin, to illustrate the role of the renin-angiotensin system in the development of systemic hypertensive vascular remodelling and hypertension. In the second part, we focus on the cerebrovascular response to hypertension and discuss new data using a conditional, transgenic model of malignant hypertension, the inducible hypertensive rat (IHR). Cerebral infarction associates strongly with hypertension in man and the mechanisms by which hypertension predisposes to different types of stroke remains poorly understood. Rats have similar cerebrovascular anatomy and structure to humans and as such provide a good experimental tool. To date, such models lack controllability and blood-pressure matched controls. Using the IHR, we have manipulated dietary salt and water intake to generate a novel, controllable stroke phenotype. Hypertensive small-vessel stroke develops over a predictable time period, permitting the study of developing cerebrovascular lesions. Systemic end-organ injury and hypertension are not affected. Dissociation of the systemic and central vascular responses in this way, will allow for comparative study of animals with equivalent hypertension, genetic background and systemic features of hypertension with or without stroke.
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PMID:The role of the renin-angiotensin system in malignant vascular injury affecting the systemic and cerebral circulations. 1476 41

Essential hypertension accounts for 95% of all cases of hypertension. A small number of patients (between 2% and 5%) have a reversible disease as the cause for raised blood pressure. Unilateral and bilateral renal artery stenosis may be responsible for secondary hypertension. Diagnosis and treatment of renal artery stenosis are of a great importance. Revascularization of ischemic kidney may correct blood pressure control and preserve renal function. Much data suggest close pathophysiological relation between renal artery stenosis, ischemic nephropathy and development of hypertension. However, it should be stressed that not every renal artery stenosis leads to hypertension and ischemic nephropathy. Therefore diagnosis of renal artery stenosis in hypertensive patient is not always equivalent with renovascular hypertension. The true prevalence of renal artery stenosis is unknown. In unselected population it accounts for less than 1% of hypertensive patients. Renovascular etiology of hypertension may be suggested by abrupt onset of hypertension, resistant and malignant hypertension or recurrent pulmonary edema of unknown etiology. Physical examination may reveal bruits over major vessels, including the abdominal aorta and renal arteries. The principle aim of the renal artery stenosis investigation is to confirm presence and size of vessel obstruction and its association with hypertension. Typical evaluation is based on imaging techniques and physiological studies. Former include: doppler duplex ultrasonography, conventional angiography, intraarterial and intravenous digital subtraction angiography, computed axial tomography, magnetic resonance angiography and intravascular ultrasonography. Functional studies are occasionally used. These are renal scintigraphy, evaluation of plasma renin activity in renal veins and evaluation of plasma rennin activity after ACE inhibition. Treatment of patients with renal artery stenosis and hypertension should restore vessel patency and inhibit its occlusion. Revascularization should elicit an improvement in or normalization of blood pressure control and renal function. Therapeutic approach include percutaneous renal artery angioplasty (PTRA), with or without stenting, revascularization by surgery and pharmacotherapy. PTRA is currently the first choice option. In general, it is simpler and similarly effective as surgical reconstruction. In some cases PTRA is completed with stent placement. It prevents immediate recoil but does not completely eliminate restenosis of revascularized artery. Surgical bypass is currently reserved for patients in whom PTRA and stenting fail and in patients with extensive atherosclerotic lesions. Patients with renal artery stenosis and hypertension should be provided with pharmacological treatment according to current recommendations. Specific procedures to limit associated risk factors of atherosclerosis should also be introduced.
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PMID:[Renovascular hypertension: is it only the top of the iceberg?]. 1497 69

Hypertension is a major risk factor for the development of serious complications affecting the heart, brain, kidneys and the vascular system, leading to death and disability on a huge scale globally. This manuscript deals primarily with the clinical strategy for the control of hypertension and only refers in passing to the population strategy and primary prevention. It also concentrates on essential hypertension and does not deal with the diagnosis and management of secondary causes of hypertension. Rather, the paper describes the clinical evaluation, laboratory investigations and management of the patient with essential hypertension. The focus of management is on patients with mild and moderate hypertension, without any discussion of the treatment of more severe hypertension, malignant hypertension or hypertensive encephalopathy. Accordingly, the emphasis is on lifestyle factors important in both prevention and treatment of hypertension and on the drug treatment of patients with elevated blood pressures in routine clinical practice. The paper does not cover special populations or problems such as hypertension of pregnancy or hypertension in children.
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PMID:Advances in the diagnosis and treatment of arterial hypertension. 1501 Jul 11


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