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Query: UMLS:C0038454 (stroke)
 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Three types of renal hypertension in the rat have been compared with respect to blood pressure increase, activity of the RAS, and secretion of aldosterone and corticosterone: type I - unilateral stenosis of the renal artery in the presence of an intact contralateral kidney; type II - unilateral stenosis of the renal artery after contralateral nephrectomy; type III - bilateral stenosis of the renal arteries. Blood pressure rose more rapidly and reached higher values in type II and type III hypertension than in type I hypertension. In the latter group, the activity of the RAS was more stimulated than in types II and III. The marked stimulation of the RAS in type I hypertension is ascribed to the negative fluid and sodium balance, which is the consequence of a pressure-induced diuresis of the unclamped contralateral kidney. Suppression of the activity of the RAS by a 4-week pretreatment with DOC-TMA and saline or by the administration of DOCA and saline as from the induction of renal artery stenosis did not prevent the development of hypertension caused by the clamping of one renal artery (type I). In spontaneously hypertensive rats of the stroke-prone substrain, high dietary salt intake caused higher blood pressure values and a higher incidence of cerebral lesions than normal dietary salt intake. Low salt intake was followed by a marked stimulation of the RAS, but blood pressure rose only slightly and no symptoms of cerebrovascular lesions were observed. It is concluded that neither in hypertension induced by renal artery stenosis nor in spontaneously hypertensive rats, the RAS contributes significantly to the increase in blood pressure nor does it play a major part in the pathogenesis of vascular lesions. These seem to be related to the retention of sodium, which may be obtained by renal artery stenosis, by excessive salt intake, or by the administration of a mineralocorticoid and salt.
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PMID:What makes the renin-angiotensin system a pathogenic factor? 69 4

We present a surgical technique that we believe provides superior cerebral protection for simultaneous correction of carotid and cardiac pathology with low operative mortality and stroke rate. Our study population consists of 23 consecutive patients undergoing cardiac operation between August 1989 and April 1991 who also had associated critical (greater than 85%) carotid artery stenosis. Using 20 degrees C systemic hypothermia for cerebral protection, we performed simultaneous correction of both lesions during the aortic cross-clamp period, using continuous retrograde blood cardioplegia for myocardial protection. Mean patient age was 69.4 years; 83% were 65 years or older. Eighty-seven percent had angina, 35% had recent myocardial infarctions (within 30 days), and 52% had congestive heart failure. Asymptomatic bruit was found in 39%, and 61% had previous strokes, neurologic symptoms, or both. All had 85% or greater luminal narrowing on cerebral angiography, with 65% having severe or critical contralateral disease as well. Sixty-one percent had associated other vascular pathology, including peripheral vascular occlusive disease, renal artery stenosis, or abdominal aortic aneurysm. There were no postoperative strokes or neurologic events. One early vein graft occlusion resulted in postoperative myocardial infarction and subsequent death (4.3%).
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PMID:Combined cardiac operation and carotid endarterectomy during aortic cross-clamping. 843 Oct 83

High renin hypertension has been associated with a higher risk of stroke than low-to-normal renin hypertension. Accordingly, we investigated prospectively the prevalence of the extracranial carotid artery lesions in a case-control study of 70 patients (38 women and 32 men, aged 16 to 77 years) without history or symptoms of cerebrovascular disease. Renovascular hypertension was diagnosed in 35 patients on the basis of the angiographic demonstration of renal artery stenosis and of the favorable outcome after revascularization. It was caused by atherosclerosis in 20 patients and by fibrodysplasia in 15. Each renovascular hypertensive patient was individually matched with a control with primary hypertension for sex, race, age, blood pressure levels, duration of hypertension, smoking, diabetes mellitus, total serum cholesterol, and triglycerides. Carotid arteries were evaluated by a High Resolution Duplex system (Biosound 2000, probe 4 cm, 8 mHz). Our results show that after the matching the two groups were similar in terms of demographic features and overall cardiovascular risk profile (all P = NS). In renovascular hypertensives the prevalence of carotid artery lesions (82.6%) was significantly (P less than .01) higher than in primary hypertensives (42.9%). The higher prevalence of lesions in renovascular hypertension was observed not only in patients with atherosclerosis (100% v 55%, P less than .001), but also in those with fibrodysplasia (57% v 27%, P less than .01). Thus, for the same demographic features and overall cardiovascular risk profile, renovascular hypertension carries a more detrimental effect on the carotid artery than primary hypertension.
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PMID:Excess prevalence of extracranial carotid artery lesions in renovascular hypertension. 129 42

The contribution of neurogenic mechanisms in maintaining hypertension was investigated in 13 patients with unilateral renal artery stenosis (twelve with normal, one with grossly elevated plasma renin levels) by determining the haemodynamic and hormonal responses to the centrally acting sympatholytic agent, clonidine. The same patients were studied after captopril to determine the dependency of their blood pressure on the direct peripheral effects of angiotensin-II. Sixteen patients with essential hypertension (normal plasma renin) were additionally studied after clonidine. After clonidine, blood pressure fell markedly in patients with renal artery stenosis (17 +/- 3%) and essential hypertension (18 +/- 2%). In both groups, clonidine lowered cardiac output by a reduction in stroke volume and heart rate; forearm vascular resistance was unchanged but digital skin vascular resistance fell. Plasma noradrenaline levels were normal in both groups and fell after clonidine; plasma renin activity and aldosterone levels were unchanged. After captopril, blood pressure fell minimally (5 +/- 3%) in renal artery stenosis patients; cardiac output fell and forearm and digital skin vascular resistance were unchanged. Plasma renin activity rose, plasma aldosterone fell and plasma noradrenaline was unchanged after captopril. In the patient with grossly elevated renin levels, blood pressure fell minimally (6%) after clonidine, but unlike others fell profoundly (37%) after captopril. We conclude that, in the majority of our renal artery stenosis patients, despite the elevated blood pressure, sympathetic nervous activity was not reduced. Central neurogenic mechanisms appear to play an important role in maintaining raised blood pressure. In the same patients the peripheral effects of angiotensin-II did not maintain vascular tone or hypertension.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:The sympathetic nervous system in hypertension due to unilateral renal artery stenosis in man. 182 52

In elderly patients with generalized atherosclerosis and longstanding hypertension, progressive renal insufficiency should suggest renal artery occlusive disease and/or renal cholesterol embolization. Renal cholesterol embolization is not an absolute contraindication to successful surgical revascularization. Renal cholesterol emboli were identified in biopsy specimens obtained in 24 cases at the Cleveland Clinic from 1978 to 1986, and renal artery stenosis was an associated finding in 19. Clinical manifestations of generalized atherosclerosis were common, including ileofemoral atherosclerosis (18), coronary artery disease (16), carotid occlusive disease (15), and carotid occlusive disease with a history of stroke (8). Evidence of embolic events in other organs was common. Hypertension worsened before biopsy in 21 patients with and without renal artery stenosis. Surgery or angiography definitely or probably contributed to renal failure in 16. Of 12 who underwent surgical revascularization of a renal artery, renal function improved in five, remained stable in five, and worsened in one. Renal function improved in the three patients undergoing dialysis before revascularization, and two were able to discontinue dialysis.
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PMID:Atheroembolic renal disease: association with renal arterial stenosis. 252 69

Moyamoya disease has been associated with renal artery stenosis, cerebral hemorrhage, and multiple cranial traumas. We report a unique case of moyamoya disease associated with polycystic kidney disease and eosinophilic granuloma. Although the etiology of moyamoya disease is unknown, a familial pattern of occurrence has been documented. Of particular importance is its presentation with polycystic kidney disease, an autosomal dominant disease, suggesting a hereditary component to the etiology of this unusual vasculitic disease.
Stroke 1989 Aug
PMID:Moyamoya disease associated with polycystic kidney disease and eosinophilic granuloma. 275 42

The role of central pressor mechanisms in the maintenance of blood pressure in six hypertensive patients with angiographically proven unilateral renal artery stenosis was investigated by studying the haemodynamic and hormonal responses before and after central sympathetic blockade with clonidine. To assess the dependency of blood pressure on the direct effects of angiotensin II, the same patients were studied on a separate occasion after administration of the angiotensin converting enzyme (ACE) inhibitor, captopril. There was a substantial fall in blood pressure after administration of clonidine with a smaller fall after captopril. Clonidine-induced hypotension was accompanied by a fall in cardiac output, through a reduction in the stroke volume and heart rate. Forearm vascular resistance was unchanged. There was a selective decrease in digital skin vascular resistance and plasma noradrenaline, indicating reduced sympathetic activity. Plasma renin activity and aldosterone levels did not fall. After administration of captopril, there was a fall in cardiac output due to a fall in the stroke volume but not in the heart rate. Forearm vascular resistance, digital skin vascular resistance and plasma noradrenaline were unchanged. Plasma renin activity rose and plasma aldosterone fell. We conclude that in our hypertensive patients with renal artery stenosis, clonidine lowered blood pressure by a reduction in central sympathetic activity independently of renin suppression. In these patients captopril had minimal hypotensive effects, indicating a smaller role for the direct vascular effects of angiotensin II.
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PMID:Cardiovascular and neurohormonal changes following central sympathetic blockade with clonidine in human unilateral renal artery stenosis. 307 92

The spontaneously hypertensive rat (SHR) and the stroke-prone substrain (sp-SHR) have been reported to have several abnormalities in levels of peptides both in tissue and in plasma (beta-endorphin, prolactin, thyroid stimulating hormone and vasopressin) when compared to the Wistar Kyoto (WKY) normotensive control rat. As the secretion of these peptides is under dopaminergic control and the abnormalities consistently suggest under-activity of the dopaminergic control system in the brain, injections of dopamine (0.4 mg/kg) were given i.c.v. to 10 SHR, 10 renal artery stenosis hypertensive rats (LRAS) and 10 genetically hypertensive rats of the New Zealand strain (GHR). Mean blood pressure fell from 205 +/- 6 (SEM) mmHg to 128 +/- 8 mmHg in the SHR (p less than 0.001), from 184 +/- 7 mmHg to 176 +/- 7 mmHg in the LRAS (p greater 0.05) and from 157 +/- 5 mmHg to 138 +/- 6 mmHg in he GHR (p less than 0.02). These effects were unlikely to be due to leakage of dopamine out into the periphery as i.v. dopamine (0.4 mg/kg) increased blood pressure in these animals.
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PMID:Neuropeptide abnormalities suggest a dopaminergic basis for high blood pressure in the spontaneously hypertensive rat. 609 77

The clinical features and course of aortitis syndrome were studied in 11 women older than 40 years of age. The patients were Japanese women, mean age 57 +/- 6 years old, who were followed for 6.9 +/- 3.8 years. Data from 24 young patients were used for comparison. In the older patients, systemic hypertension (73%), calcification of the aorta (73%), left ventricular hypertrophy (92%) and cardiomegaly (82%) were frequent, whereas the erythrocyte sedimentation rate was normal in 5 patients and only slightly accelerated in 6. C-reactive protein was positive in 2. The incidence of cardiac involvement and inflammatory signs was significantly different from findings in the young patients. Aortic regurgitation (AR) (55%) was significantly more frequent and renal artery stenosis was not observed. Other arterial lesions revealed a pattern similar to those seen in the young patients. An irregular luminal surface, kinking and calcification were present in the lesions in the older patients. The survival rate at 5 years was 80%. Five of 6 patients with AR had congestive heart failure, 4 of whom died. One died after a stroke. Thus, aortitis syndrome in older patients has a long course. There is usually an associated AR, renal artery stenosis is rare and other arterial lesions do not change a great deal. The prognosis may be good, but depends on the association of AR.
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PMID:Clinical features and course of aortitis syndrome in Japanese women older than 40 years. 614 41

Renovascular hypertension is one of the most common causes of secondary hypertension. Its early diagnosis is particularly important, firstly because it is one of the few potentially reversible causes of chronic renal failure. In many centers, including our own, renal angioplasty (PTA) or surgery is the treatment of choice for patients with renovascular hypertension. The aim of the study was the evaluation of the early and late results of PTA versus renovascular surgery. The diagnostic procedures and clinical course of renovascular hypertension were also analyzed. Among patients with renovascular hypertension treated in our Department during the 1981-1993 years, 89 patients (46 men, 43 women) were diagnosed and having renovascular hypertension (3% of all hypertensive patients). The average duration of hypertension in this group was 5 years. High incidence of accelerated hypertension (18%) and cardiovascular complications were observed: myocardial infarction in 20.2% of cases and stroke in 4.5%. The presence of renal failure was found in 22.5% of cases, hypokalemia in 11.2%, 38.3% of patients had changes in other arteries. Renal angioscintigraphy and captopril renal scintigraphy were performed in accordance with renal arteriography in 80% of patients. Arteriography showed unilateral renal artery stenosis in 78.7% of patients and bilateral - in 21.3%. The most common cause of renovascular hypertension in our material was atherosclerosis (65.2%). Fibromuscular dysplasia and Takayasu arteritis were diagnosed less frequently (25.8% and 9.0% respectively). Forty four patients were treated with PTA, 15 underwent surgical revascularization and 11 - unilateral nephrectomy. Early beneficial therapeutic effect (normalization or improvement of blood pressure control) was observed in 88.6% for PTA and 66.7% for surgery.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Renovascular hypertension--clinical observations and long-term follow-up]. 787 Dec


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