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

The renal vascular response to graded doses of acetylcholine, dopamine and phentolamine, assessed by xenon washout and selective arteriography was used to define the relative contribution of fixed and reversible vascular abnormalities to increased renal vascular resistance in patients with essential or secondary hypertension. The increase in blood flow induced by acetylcholine and dopamine was blunted strikingly in patients with advanced nephrosclerosis, chronic pyelonephritis and polycystic kidney disease and was normal in the kidney contralateral to a significant renal artery stenosis. Conversely, the response to both was potentiated in 9 of 13 (69%) patients with mild essential hypertension. Equivalent potentiation of the response to acetylcholine was induced in normal subjects by increasing renal vascular tone pharmacologically with angiotensin. Phentolamine infused into the renal artery also increased renal blood flow significantly in 6 of 9 (67%) patients with mild essential hypertension, but in none of 15 normal subjects, over a dose reange that paralleled that for alpha-adrenergic blockade. Changes in the selective renal arteriogram were in excellent accord: potentiated response to acetylcholine, phentolamine or dopamine was associated with reversal of the small vessel abnormalities visualized in the arteriogram. The reduced blood flow response in advanced nephrosclerosis or parenchymal disease was associated with a reduced angiographic change during dilator infusion. The results suggest a quantitatively important, functional renal vascular abnormality--perhaps mediated by the sympathetic nervous system--in many patients with mild essential hypertension. Conversely the renal vascular abnormality associated with advanced nephrosclerosis or renal parenchymal disease is largely fixed and is probably due to organic changes.
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PMID:Renal vascular tone in essential and secondary hypertension: hemodynamic and angiographic responses to vasodilators. 23 62

Renin-aldosterone profiling was used to classify patients with hypertension: 243 patients with essential hypertension were classified by renin-urinary sodium indexing; 107 were reclassified by response to administration of furosemide and intravenous saline; 45 were further classified by response to a low-sodium diet. Arbitrary "normal ranges" were determined in 89, 32, and 38 volunteers, respectively. Patients with low-renin apparently do not have "high-volume" hypertension. Rather, they show a primary renal abnormality in renin secretion and become relatively deficient in angiotensin II and aldosterone when they are subjected to diuresis. They can maintain aldosterone secretion under normal conditions because their adrenal aldosterone receptor is supersensitive to angiotensin II. No evidence of abnormal sympathetic neural activity was found among the renin subgroups. Renin-aldosterone profiling in current clinical practice seems useful mainly in the detection of patients with curable forms of secondary hypertension. Aldosterone/renin ratios may be particularly helpful in diagnosis when obtained after a patient has undergone expansion or contraction of his extracellular fluid volume.
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PMID:Renin-aldosterone profiling in hypertension. 33 42

To test whether central neurogenic factors participate in blood pressure elevation in primary hypertension, we studied the concentrations of: norepinephrine, epinephrine and dopamine-beta-hydroxylase (DBH) in cerebrospinal fluid (CSF); and norepinephrine, epinephrine, DBH and plasma renin activity (PRA) in plasma of 22 subjects (seven with primary hypertension, 11 normotensive patients with non-systemic neurological disorders, and four with secondary hypertension). Plasma and CSF norepinephrine (NE) were increased in primary hypertensives compared to normotensives. Cerebrospinal fluid norepinephrine was related to diastolic blood pressure, and systolic blood pressure when normotensive and primary hypertensives were taken together. The CSF norepinephrine of primary hypertensive patients was correlated with natural log PRA. The CSF norepinephrine was correlated inversely with age in primary hypertensive patients but not in the normotensive subjects. The low CSF norepinephrine and epinephrine, despite markedly increased plasma NE and epinephrine, in two patients with pheochromocytoma, indicate a blood-brain barrier for these neurohormones. The observations support the view that the central sympathetic nervous system is involved in the pathogenesis of primary hypertension, particularly in younger patients.
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PMID:Raised cerebrospinal fluid norepinephrine in some patients with primary hypertension. 39 37

The pathological changes in blood vessels observed in primary (essential hypertension) are similar to those seen in secondary hypertension due to renal disease or other causes. In benign hypertension, the major changes are in the small arteries and arterioles especially in the kidney. Interlobular arteries exhibit intimal thickening and duplication of the elastic lamina (elastosis) and there is hyaline change in the media of many arterioles. In some respects these changes are an accentuation of vessel ageing. Malignant hypertension usually presents in a younger age group (35--50 years) and is characterized pathologically by fibrous endarteritis in the interlobular arteries of the kidney and fibrinoid necrosis in the walls of a proportion of the efferent glomerular arterioles. Similar vessel changes are seen in other organs but many of the pathological changes in the heart and brain of patients with benign hypertension are related to the accentuation of arterosclerosis. There is an increased mortality from cardiac failure, myocardial infarction, cerebral haemorrhage and subarachnoid haemorrhage due to ruptured berry aneurysms in patients with benign hypertension. Although there is ischaemic damage to the kidneys in benign hypertension, death from renal failure is uncommon. Severe ischaemic damage to renal glomeruli and renal failure does, however, occur in malignant hypertension.
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PMID:Vascular pathology in hypertension. 46 85

The value of radiological examinations in hypertension was analyzed in a series of 44 children. An i.v. urography had been performed in 43 cases with a pathological finding in 19 (44%). Renal angiography, employed in 19 cases, revealed abnormal findings in 12 (63%) patients. Micturating urethrocystography performed in 16 children gave no additional important information. The only complication noted was thrombosis of the femoral artery subsequent to renal angiography in one child less than one year of age. The diagnosis of hypertension based mainly on the i.v. urography in 12 cases but the renal angiography gave additional important information in 6 children. One child with obstructive hydronephrosis was also found to have a renal artery stenosis at renal arteriography. Based on these results, and particularly because secondary hypertension may frequently be treated surgically, we consider extensive radiological investigation with renal angiography is mandatory before receiving a final diagnosis of essential hypertension, and before starting long-term treatment.
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PMID:The radiological evaluation of children with hypertension. 51 Mar 18

Racial differences in prevalence of essential hypertension are well known. In order to explore these differences at an early age in terms of etiology, we investigated schoolchildren in an entire, biracial community. A sample of 278 children, stratified by diastolic (fourth-phase) blood pressure and specific for age, race, and sex, was reexamined 1--2 yr after initial observation for the following: (1) a physical examination and urinalysis to exclude secondary hypertension; (2) 24-hr urine sodium, potassium, plasma renin activity, and serum dopamine beta-hydroxylase; (3) 1-hr oral glucose tolerance test; and (4) heart rate and blood pressure at rest and under standarized physical stress. We found that 24-hr urine sodium was positively associated with blood pressure level as measured on the same day for the high blood pressure strata of black children. Urine potassium excretion was lower in blacks than in whites, although their intakes seemed equal. In the high blood pressure strata especially, black boys had lower renin activity than whites, and the resting-supine and stressed systolic blood pressures were higher in black boys than in any other group. In these black boys, resting and stressed systolic pressures were negatively related to plasma renin activity. On the other hand, dopamine beta-hydroxylase levels in white children were higher than in blacks for all blood pressure strata, and in the high blood pressure strata white children had higher 1-hr glucose levels and faster resting heart rates than black children. Different mechanisms may play a role in and contribute to the early stage of essential hypertension.
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PMID:Racial differences of parameters associated with blood pressure levels in children--the Bogalusa heart study. 51 82

In normal pregnant women the excretion of urinary kallikrein diminishes between the second and the third trimester and such reduction is maintained during the first ten days of puerperium. A comparison between normal women and those suffering from hypertension during the first, second and third trimester of pregnancy shows that, except for the first trimester, there exists a significant net reduction of enzyme excretion in the hypertensive cases. Dividing the patients according to the type of hypertension, it reveals that this phenomenon is unaltered for subjects having essential hypertension, while those affected by secondary hypertension or gestosis do not show any statistically significant variation in enzyme excretion from normal subjects.
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PMID:Variation of urinary kallikrein excretion during pregnancy and the effects of hypertension. 51 57

A follow-up was made of 69 patients diagnosed as having malignant hypertension during 1969--76, essential in 26, secondary in 39 and unclassified in 4. A clear male dominance was seen (41 men, 28 women), particularly in the group with essential hypertension (18 men, 8 women). The mortality in this series was less than in previously published series. Thus, the 5-year survival rate was 75% in the patients with essential and 72% in those with secondary hypertension. In part this was due to haemodialysis and renal transplantation. The importance of renal function at the time of diagnosis was evident in this study. In most patients with essential hypertension and serum creatinine levels below 300 mumol/l, renal function could be maintained or improved when antihypertensive treatment was instituted, whereas progression of the renal damage was seen in those with serum creatinine levels above 300 mumol/l in spite of antihypertensive treatment with 3 or more drugs. The incidence of new cases of malignant hypertension tended to decrease during the observation period, particularly as regards essential hypertension.
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PMID:Malignant hypertension--improving prognosis in a rare disease. 53 11

This study describes the seated blood pressure distributions of 6,622 predominantly white schoolchildren in Muscatine, Iowa. Subjects with seated pressures equal to or greater than the 95th percentile for age and sex or 140 mm Hg systolic or 90 mm Hg diastolic were examined on repeated occasions. Approximately 13% of subjects were found to have blood pressures at these levels when first examined, but less than 1% were found to have persistent blood pressure elevations. Of 41 subjects found to have persistent blood pressure elevations, 23 were obese with relative weights in excess of 120%. Of the 18 lean subjects, 5 had secondary hypertension and 13 were considered to have essential hypertension. Mass screening of school-age children identifies many children with transient elevation of blood pressure and few with fixed high blood pressures. Children's blood pressures should be assessed during their continuing care where pressures can be measured over a period of time to identify those with fixed blood pressure elevations.
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PMID:Normal blood pressure and the evaluation of sustained blood pressure elevation in childhood: the Muscatine study. 63 79

An analytical study of the renin-angiotensin-aldosterone system was made in 124 individuals with essential hypertension, aged from 25 to 55 years. The results obtained, with rigorous control to posture and sodium balance, indicate the existence of a number of subgroups of hypertensive subjects related to their renin activity and plasma aldosterone in the upright position. This classification thus makes possible comparison with patients suffering from secondary hypertension.
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PMID:[The renin-angiotensin-aldosterone system in hypertensive subjects. I-Analytical study of 124 patients (author's transl)]. 91 87


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