Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0085580 (essential hypertension)
 14,686 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Frederick Akbar Mahomed was an Englishman of mixed Indian and Irish descent who made substantial contributions to the study of high blood pressure in a short professional life from 1872 to 1884. He was strongly influenced by the previous work of Richard Bright on kidney disease at his own hospital (Guy's Hospital in London) and by the contemporary pathological studies of Gull and Sutton on arteriolar changes in persons with high blood pressure. In detailed clinical studies, he separated chronic nephritis with secondary hypertension from what we now term essential hypertension. He described the constitutional basis and natural history of essential hypertension and pointed out that this disease could terminate with nephrosclerosis and renal failure. His clinical studies were done without the benefit of a sphygmomanometer but with the aid of a quantitative sphygmogram that he had initially developed while a medical student. He described characteristic features of the pressure pulse in patients with high blood pressure and in persons with arteriosclerosis consequent on aging. These pressure wave changes have recently been verified and explained. He contributed to a number of other advances in medical care, including blood transfusion and appendectomy for appendicitis. He initiated the Collective Investigation Record for the British Medical Association; this organization collected data from physicians practicing outside the hospital setting and was the precursor of modern collaborative clinical trials. Mahomed died from typhoid fever, almost certainly contracted from one of his patients, at age 35 at the height of his career.
 ...
PMID:Frederick Akbar Mahomed. 173 55

The term 'secondary hypertension' includes a variety of aetiological processes with no obvious common feature apart, perhaps, from the loss of normal blood pressure regulatory factors. It has been suggested that all forms of secondary hypertension, including renal/renovascular, accelerated phase, glucocorticoid and mineralocorticoid excess, phaeochromocytoma and toxaemia in pregnancy are associated with the loss of the normal nocturnal fall in blood pressure. The evidence for this view appears strongest for glucocorticoid-induced hypertension, but for most other forms the available data are conflicting and are mostly based on small numbers of patients without adequate control populations. Sleep is a powerful determinant of the nocturnal fall in blood pressure but few studies have addressed the quality of sleep in groups of patients who are often sick and/or hospitalized. Abnormalities in sympathetic drive (e.g. autonomic neuropathy and phaeochromocytoma) can abolish the nocturnal blood pressure reductions, and activation of the sympathetic nervous system may be a critical factor in determining the normal diurnal changes in blood pressure. As approximately 20% of patients with 'essential hypertension' have a blunted fall in nocturnal blood pressure it seems unlikely that ambulatory blood pressure could ever be useful in screening for secondary hypertension.
 ...
PMID:Ambulatory blood pressure monitoring in secondary hypertension. 179 8

Circadian blood pressure variability was recorded in patients with primary hypertension and with different forms of secondary hypertension using ambulatory 24-h blood pressure measurement. A group of 20 patients with different forms of secondary hypertension was compared with a matched group of patients with primary hypertension. Although the mean 24-h blood pressure was not different between the two groups, the patients with secondary hypertension had significantly higher systolic blood pressure during sleep and higher systolic and diastolic blood pressure in the early morning, compared with the primary hypertension group. This nocturnal blood pressure fall was then investigated in various groups of patients with different forms of secondary hypertension and compared with normotensives and patients with primary hypertension. Patients with mild primary hypertension (n = 152) and with severe primary hypertension (n = 30) had the same blood pressure fall (14-16 mm Hg systolic and diastolic) during the night (23:00-05:00 h) as normotensives (n = 20). However, in patients with renoparenchymal hypertension (n = 29), renovascular hypertensions (n = 20), hyperaldosteronism (n = 6), and hyperthyroidism (n = 14), the nocturnal blood pressure fall was significantly (p less than 0.01) reduced. One patient with coarctation of the aorta and nine patients with primary hyperparathyroidism and elevated blood pressure had a normal circadian blood pressure profile with a normal nocturnal blood pressure fall. The heart rate decrease during the night was equal in all patient groups. Ambulatory blood pressure measurement allows blood pressure recording under everyday conditions, including nighttime. In primary hypertension the blood pressure variability exhibits the same circadian variation as in normotension, showing a marked nocturnal fall.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Circadian blood pressure rhythm in primary and secondary hypertension. 179 27

Previous studies, including our own, have demonstrated that muscle sympathetic nerve activity (MSNA) is increased in patients with essential hypertension compared with normotensive subjects. However, the features of sympathetic nerve activity are still unknown in secondary hypertension. We examined MSNA in eight patients with renovascular hypertension and in 11 patients with primary aldosteronism. Twenty patients with essential hypertension and 20 normotensive subjects who were age-matched to the patients with renovascular hypertension and those with primary aldosteronism were also studied. The MSNA of a bundle of the tibial nerve was recorded by microneurography in supine subjects and expressed as both burst rate (bursts/min) and burst incidence (bursts/100 heart beats). Plasma renin activity and the plasma concentration of angiotensin II and aldosterone were also measured. MSNA was increased in the patients with renovascular hypertension compared with the patients with primary aldosteronism and those with essential hypertension and the normotensive subjects (p less than 0.01 for each). MSNA was decreased in the patients with primary aldosteronism compared with those with essential hypertension (p less than 0.01), and it was smaller than in the normotensive subjects (p less than 0.1). Furthermore, MSNA, plasma renin activity, and the plasma concentration of angiotensin II decreased significantly in five patients with renovascular hypertension 4-10 days after successful percutaneous renal angioplasty. Thus, the changes in MSNA seem to characterize the pathophysiology of renovascular hypertension and primary aldosteronism. Activation of the renin-angiotensin system may be involved in the increase in the central outflow of sympathetic nerve activity, thus exacerbating hypertension in patients with renovascular hypertension.
 ...
PMID:Muscle sympathetic nerve activity in renovascular hypertension and primary aldosteronism. 182 57

Secondary hypertension represents about 5-10% of all forms of hypertension, renal and renovascular being the commonest forms. Renal artery stenosis is the principal cause of renovascular hypertension due to atheromatous disease or fibromuscular dysplasia. Rapid sequence intravenous pyelogram, isotope renogram, captopril test and digital subtraction angiography or conventional arteriography, are the diagnostic procedures in the diagnosis of renal artery atenosis. Hypertension is also very common in parenchymal renal disease, mainly in chronic renal insufficiency. In this condition, the mechanism is more related to volume dependent factors than in renovascular hypertension which is mainly renin dependent. In the treatment of renal or renovascular hypertension the same type of drugs have been generally used as in essential hypertension although with some specific indications like the use of angiotensin-converting enzyme inhibitors in unilateral renal artery stenosis or furosemide in case of renal insufficiency. Revascularization by angioplasty or surgical bypass, may be indicated in renovascular hypertension.
 ...
PMID:[Hypertension from the nephrologist's point of view]. 183 18

This paper deals with the following hypertension diagnoses: essential hypertension and five types of secondary hypertension: fibrodysplasic renal artery stenosis, atheromatous renal artery stenosis, Conn's syndrome, renal cystic disease, and pheochromocytoma. Only blood pressures, general information and general biochemical data are taken into account. Nineteen items were finally selected, by statistical investigation of experimental data, as being both discriminative and independent. The marginal density distributions of every item, and then joint density distribution functions were determined within six types of hypertension. The frequency of a given hypertension type within the hypertensive patients was used as prior probability of this state. The loss matrix was established by medical arguments. The expected loss corresponding to six possible decisions could thus be calculated for all cases. Both the ratio of secondary hypertensions that could be inferred from our set of data (not including the results of complementary tests) and that of correct "essential" hypertension diagnosis proved to be satisfactory.
 ...
PMID:Bayesian statistics as applied to hypertension diagnosis. 187 63

A typical diurnal variation in blood pressure is observed in patients with essential hypertension. Attenuation or lack of circadian periodicity might be expected in patients with secondary hypertension. Therefore, non invasive ambulatory blood-pressure monitoring was performed in 172 patients with secondary hypertension and in 201 patients with essential hypertension. The following patients with secondary hypertension were investigated: renoparenchymatous nephropathy (n = 29), diabetic nephropathy (n = 24), morbus Conn (n = 6), renal artery stenosis (n = 32), pheochromocytoma (n = 5), hemodialysis patients (n = 30), and patients after kidney transplantation (n = 44). In addition, 36 pregnant women (17 normotensives, 19 hypertensives) were studied. 98.5% of patients with essential hypertension showed a nightly decline in blood pressure of at least 15 mmHg (systolic + diastolic), whereas 70% of patients with secondary hypertension showed either an attenuated circadian rhythm or no circadian rhythm. Patients with pheochromocytoma who had a nighttime increase in blood pressure demonstrated the greatest difference in the essential hypertension collective, followed by patients with diabetic nephropathy and patients after kidney transplantation. After successful treatment of the condition leading to hypertension, circadian periodicity returned in some patients. In summary, these results suggest that the absence of a nighttime decline in blood pressure during 24-h-ambulatory monitoring is an indication of secondary hypertension, which should be further investigated. As a practical consequence, antihypertensive drugs should also be applied in an evening dose in secondary hypertensives. Noninvasive ambulatory blood-pressure monitoring is recommended for treatment control, especially in patients who need an efficient blood-pressure control.
 ...
PMID:[Importance of 24-hour blood pressure monitoring in secondary hypertension]. 202 30

The authors investigated the incidence of arterial hypertension during acute glomerulonephritis in adults and during the period after glomerulonephritis. Hypertension was recorded in 34% of 126 patients treated on account of acute glomerulonephritis (mean age 23 +/- 6 years). Only in six patients the diastolic pressure was higher than 15.3 kPa. At the end of hospitalization hypertension persisted in four subjects. After a three-year interval following glomerulonephritis hypertension was recorded in 15% of 119 examined subjects. In 7 subjects it was isolated, in another 11 associated with a pathological finding in urine. Four to twenty years after acute glomerulonephritis (mean 11.5 years) in a group of 81 subjects hypertension was recorded in 31%. In six patients it was an isolated finding, in 19 instances it was associated with a pathological finding in urine and possibly impaired renal function. In adult age transient hypertension is associated with about one third of all cases of acute glomerulonephritis. Subsequent presence of hypertension in these patients is frequent and increases with the follow up period. Without an invasive examination it is not possible differentiate secondary hypertension from essential hypertension, in particular in subjects with isolated hypertension or hypertension associated with mild proteinuria.
 ...
PMID:[Incidence of arterial hypertension during and after acute glomerulonephritis]. 205 96

With 60 million Americans meeting criteria for either essential or secondary hypertension, elevated arterial pressures remain a major health problem. While efforts to find etiologies for essential hypertension continue, clinicians battle its effects on organ systems, including the nervous system. Hypertensive changes in the nervous system may be acute, chronic, or both. The intracerebral vasculature is commonly affected. Not infrequently, acute changes including hemorrhage, encephalopathy, and cerebral edema are superimposed on chronic changes of hyaline and fibrinoid arteriolosclerosis. Chronic vascular changes sacrifice vascular lumina. The resulting ischemia is responsible for cystic (lacunar) lesions and subcortical ischemic white matter lesions consistent with Binswanger's disease.
 ...
PMID:The effects of hypertension on the nervous system. 206 1

Since the pathogenesis of essential hypertension has not yet been clarified, laboratory examinations are needed to identify secondary hypertension and to classify the patients with essential hypertension into subclasses. We reviewed the recent topics on hypertension-research related to laboratory examinations such as 1) recording of arterial pressure, 2) plasma renin activity and digitalis-like substances as the cause of essential hypertension, and 3) atrial natriuretic polypeptides and endothelin, as possible indices of atherosclerosis, one of major complications of hypertension.
 ...
PMID:[Pathophysiology and laboratory examinations of essential hypertension--a review of recent topics]. 214 38


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>