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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A 70-year-old woman with chronic hypertension and previously normal renal function had acute oliguric renal failure requiring hemodialysis. Renal arteriograms revealed the presence of bilateral renal artery stenosis and normal-sized kidneys. Nineteen days after admission to hospital, after undergoing nine hemodialysis procedures, surgical revascularization of renal artery stenosis was performed utilizing a single bypass graft of the left renal artery. Postoperatively, an immediate diuresis ensued, with resolution of acute renal failure. It is critically important in the evaluation of patients with anuria, acute renal failure without obvious cause, or impending uremia in patients with chronic stable renal insufficiency, to consider the possibility of renal artery stenosis or thrombosis. Recognition and then surgical correction of significant renal arterial hypoperfusion allows the reasonable potential for reversibility of this important form of acute or progressive renal failure.
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PMID:Bilateral renal artery stenosis causing acute oliguric renal failure. Report of a case corrected by renovascular surgery. 85 4

In hypertensive patients over 50 years of age, the high prevalence of renovascular hypertension (31 per cent), the low operative risk for its correction (1 to 2 per cent), and the frequency of benefit from operation (80 to 87 per cent) support an aggressive attitude toward screening and management. Diastolic hypertension greater than 105 mm Hg in the older patient warrants investigation. If such a patient has advanced atherosclerosis with evidence of significant cardiac disease or cerebrovascular disease, the indications for operative management of renovascular hypertension correlated with the severity of hypertension, difficulty of control, and imminence of renal function deterioration. If complicating risk factors are not severe, any patient with diastolic hypertension greater than 105 mm Hg is considered an appropriate operative candidate. In contrast, when risk factors are severe, operative management is undertaken only when hypertension is difficult to control or deterioration of renal function is thought to be secondary to the renal artery stenosis. In these patients the risk of operation is obviously greater and the long term benefits are more limited. Nevertheless, based on our experience, we feel the risk of poorly controlled hypertension or impending renal failure is even higher and justifies operative intervention. Hypertension accelerates the progress of atherosclerosis, and halting or slowing the unrelenting course of atherosclerosis is worthwhile objective if this can be done without unnecessary risk.
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PMID:Surgical management of renovascular hypertension in older patients. 85 6

In a Zurich outpatient clinic in 1975 hypertension was found in 10.4% of 8228 patients (3657 females and 4571 males). Essential (primary) hypertension was found in 92.9% of all hypertensives. Among secondary forms of hypertension (7.1%) renal hypertension was the most common (5.8%) with 4.9% for hypertension of renal parenchymatous origin, .8% renovascular hypertension, and .1% hypertension associated with unilateral hydronephrosis. In 2 patients (.2%) the underlying disease was primary aldosteronism and in 5 (.6%) coarctation of the aorta. In 4 females (.5%) hypertension was caused by oral contraceptives. Patients with essential hypertension had higher body weight than those with normal blood pressure. These differences were statistically significant in young and middle-aged patients. The percentage of primary hypertension was significantly high. In only 18 (2.1%) of 854 hypertensives was a curable form of high blood pressure found (hypertension caused by renal artery stenosis, hydronephrosis, aldosterone-producing adenoma of the adrenal gland, and oral contraceptives). The very low percentage of curable forms of high blood pressure should be kept in mind when deciding on expensive procedures in a search for secondary forms of high blood pressure.
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PMID:[Primary and secondary hypertension in polyclinical patients]. 85 17

Changes in plasma renin activity (PRA) and sodium balance were studied in hypertensive rabbits and dogs with one renal artery constricted and the other kidney intact (two-kidney hypertension); aldosterone secretion was measured also in the chronic hypertensive rabbits. Both PRA and aldosterone secretion were normal in some chronic hypertensive rabbits but elevated in others. Sodium balance studies revealed that some severely hypertensive rabbits with elevated PRA were in spontaneous negative sodium balance. Unlike the rabbit, PRA was never increased in the chronic hypertensive dog and sodium balance was normal. Infusion of [Sar1, Ala8]angiotensin II (P-113) decreased arterial pressure and aldosterone secretion in those hypertensive rabbits with elevated PRA but not in those rabbits with normal PRA; P-113 also did not decrease arterial pressure in the chronic hypertensive dog unless sodium depletion was superimposed. In the conscious two-kidney dog, acute renal artery stenosis increased both arterial pressure and PRA within minutes, and P-113 blocked the rise in pressure associated with the increase in PRA. Therefore, although apparent species differences between the rabbit and the dog occur, the present data indicate that neither increased PRA nor excess salt retention is essential to the chronic maintenance of two-kidney hypertension in these two species; however, in the dog a role for angiotensin II in the acute phase is indicated.
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PMID:Mechanisms involved in two-kidney renal hypertension induced by constriction of one renal artery. 87 Feb 29

A recently developed 1-day screening procedure for angiotensinogenic ("high-renin") hypertension is based on (A) a fall in blood pressure in response to intravenous infusion of the angiotensin antagonist, saralasin (P-113), and (B) peripheral venous renin assays by radioimmunoassay, in a sodium-depleted state. Out of 700 hypertensive patients screened by these tests, 160 had renal imaging performed with technetium-99m glucoheptonate and iodine-131 Hippuran. The P-113 infusion test proved superior to peripheral venous renin assays for the detection of angiotensinogenic hypertension. Positive infusion tests correlated well with renal vein renin assays. Frequently, however, both these tests were positive with bilateral renal disease and/or malignant hypertension. While renal imaging proved valuable in indicating which patients had a unilateral abnormality, it frequently could not distinguish unilateral renovascular disease from unilateral parenchymal disease unrelated to angiotensinogenic hypertension. Twenty-five patients in this series had arteriographic renal artery stenosis, of whom 3 had false negative P-113 infusion tests, 9 had negative peripheral renin assays, and 3 had no imaging abnormalities. This study indicates that scintigraphy is a useful procedure for the investigation of hypertensive patients when the initial P-113 infusion test is positive, or discordant with other findings. By imaging, angiotensinogenic hypertension due to bilateral renal disease can be distinguished from unilateral renovascular disease, and the site of the ischemic renal tissue can usually be identified.
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PMID:Diagnosis of angiotensinogenic hypertension: the complementary roles of renal scintigraphy and the saralasin infusion test. 87 45

Saralasin, an angiotensin II antagonist, was infused into 49 patients with renal artery stenosis, 10 patients with essential hypertension and normal renal arteriograms, and five patients with "low-renin essential hypertension." Renal venous renin and differential renal function studies were used to assess the functional significance of arterial stenoses. "Response" to saralasin, evidenced by a fall in blood pressure during infusion, occurred in no patients with "low renin" hypertension and in only 20% of patients with normal renal arteriograms. In contrast, saralasin "response" occurred in more than 80% of patients with renal artery stenosis and lateralizing functional studies and 100% of cases of "proven" renovascular hypertension (cure or improvement of hypertension after operative treatment). We suggest that saralasin infusion might be a valuable screening test for the recognition of renovascular hypertension.
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PMID:Saralasin infusion in the recognition of renovascular hypertension. 87 17

We reviewed the records at the Mayo Clinic for the years 1973, 1974, and 1975 to determine the number of patients with hypertension who had had operations for repair of renal artery stenosis, excision of pheochromocytoma, or resection of aldosterone-producing adenoma. During the years studied, the average numbers of procedures per year were, respectively, 46.7, 10.3, and 2.7. For the purpose of estimating the frequency of each one of these three conditions among the population of hypertensive patients examined at the Mayo Clinic, we applied age- and sex-specific incidence figures from the US National Health Survey to the 162-273 patients examined who were more than 15 years old in 1974. We estimate that there were 26,589 patients who had diastolic blood pressures equal to or greater than 95 mm Hg. The indices generated estimated that renal artery stenosis repair was done in 18/10,000 (0.18%) hypertensive patients, pheochromocytoma excision in 4/10,000 (0.04%), and aldosterone-producing adenoma resection in 1/108000 (0.01%). These indices are strikingly lower than those frequently reported elsewhere, suggesting that these conditions are truly rare among hypertensive patients seen in clinical practice.
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PMID:Frequency of surgical treatment for hypertension in adults at the Mayo Clinic from 1973 through 1975. 89 97

In four patients with hypertension and angiographically pronounced unilateral renal artery stenosis, kallikrein activity was estimated in each kidney separately by the determination of kinin output in the renal veins. All patients showed suppression of renin release from the kidney with a non-stenotic artery. Accordingly, plasma flow from the kidney with artery stenosis could be estimated. The ratio of venous output of kinins between the kidney with a non-stenotic artery and the one with artery stenosis was 2.6-6.5. This indicates that renal artery stenosis leads to diminished intrarenal kinin generation. Reduced kinin formation may explain the low diuresis and natriuresis found in the kidney with artery stenosis.
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PMID:Renal venous output of kinins in patients with hypertension and unilateral renal artery stenosis. 91 Jun 36

A case of hypertension with simultaneous occurrence of a para-aortal pheochromocytoma and a functionally significant membranous renal artery stenosis is reported. The pheochromocytoma was excised surgically and a vein patch angioplasty was performed. Postoperatively the BP returned to normal. Three years after surgery the patient is normotensive and urinary catecholamines are normal. On the basis of this case and 27 previously reported cases of pheochromocytoma and renal artery stenosis, the possible relationship between the two conditions is discussed.
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PMID:Pheochromocytoma and renovascular hypertension. A case report on a review of the literature. 91 Jun 42

Despite recognized limitations, the renal vein renin ratio (RVRR) remains the most commonly used index of surgical curability in hypertensive patients with renal artery stenosis. It is generally held that a ratio exceeding 1.5 forecasts a favorable response to surgery. Measurement of this ratio in 40 patients with essential hypertension (no arteriographically demonstrated stenosis) showed 8 (20%) with RVRR over 1.5, confirming an overlap of this ratio between patients with essential and renovascular hypertension. Intra-arterial injection of contrast material influenced renal vein renin activity (RVRA) in some individuals, but we were unable to demonstrate significant alterations in the group as a whole. Since the influence of intra-arterial contrast material on RVRA is variable and unpredictable, it appears unwise to collect renal venous blood for renin measurements soon after angiography.
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PMID:Renal vein renin activity in primary hypertension: variability and influence of contrast material. 91 86


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