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

The validity of noninvasive (iodine-131 iodohippurate renogram, iodine-131 ortho-iodohippurate clearance, indium-113m EDTA--technetium-99m DTPA sequential renal scan) and invasive (xenon-133 washout) radionuclide screening tests was evaluated in the diagnosis of 105 patients with unilateral renovascular hypertension (RVH) and in 45 patients with essential hypertension (EH). In RVH positive findings on the stenosed side were noted in 73% of renograms, 73% of o-iodohippurate-clearance tests (N = 22), 81% of sequential renal scans, and 90% of xenon-washout studies (N = 67). In a subgroup of 55 retrospectively selected patients with normal or improved blood pressure following renovascular surgery, the preoperative findings had been positive on the stenosed side in 78% of renograms, 75% of o-iodohippurate-clearance tests (n = 20), 85% of sequential renal scans, and 93% of xenon-washout studies (n = 23). The sequential renal scan appears to be a sufficiently reliable method in noninvasive screening for unilateral RVH, although invasive xenon-washout studies show a higher percentage of hemodynamic alterations in the stenosed kidney. o-iodohippurate clearance tests, and in particular xenon-washout studies, can reveal arteriosclerotic lesions in the contralateral, non-stenosed kidney, which may be of importance when the decision for renovascular surgery is pending.
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PMID:Predictive value of radionuclide methods in the diagnosis of unilateral renovascular hypertension. 43 31

Changes in renal function caused by angiotensin-converting-enzyme (ACE) inhibitors can be detected on 99mTc-DTPA renography so that DTPA scanning before and after a single dose of captopril can be used to screen for renovascular disease. We have performed captopril-DTPA scans with renal arteriography on 104 patients, of whom 27 had renal artery stenosis, all due to atheroma. Using a 5% fall in divided function or a delay of greater than 15 min in time to peak activity on one side after captopril, or the finding of greater than 90% divided function on one side before captopril as criteria for a positive scan, a sensitivity of 93% and specificity of 70% was achieved. The negative predictive value of the test in our population was 93%. Bilateral improvement in renographic function after captopril was seen in patients with accelerated phase hypertension. The presence of bilateral renal artery disease did not reduce the sensitivity of the test, but sensitivity was reduced (75%) in patients with renal impairment. Clinical characteristics in our patients most strongly associated with renal artery stenosis were abdominal bruit, recurrent left ventricular failure, and peripheral vascular disease. In view of the well-publicized risks of ACE inhibitor therapy, care should be exercised in the use of these agents in such patients.
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PMID:Screening for renovascular disease with captopril-enhanced renography. 131 91

Technetium-99m DTPA renograms were performed before and after angioplasty in a 63-year-old man with bilateral renal artery stenosis (RAS), hypertension, and renal insufficiency. Decreased isotope uptake after captopril by the right kidney assisted in the selection of the right renal artery for angioplasty. Post-angioplasty improvement in both blood pressure control and renal function was accompanied by an absence of effect of captopril on the isotope uptake by the right kidney. In bilateral RAS, the captopril renogram is a useful tool for selecting the site for angioplasty, for assessing the adequacy of the procedure, and for long-term follow-up.
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PMID:The captopril renogram in percutaneous transluminal angioplasty of the renal arteries. 138 92

Using the nuclear medicine procedures it is possible to evaluate the renovascular hypertension via the captopril test. Decreased renal blood flow due to stenotic vessel may produce a variety of findings on the renogram using both OIH-I131 and DTPA-Tc99m. Delayed transit time and excretion also may be detected. In this situation the sensitivity and specificity of Nuclear Medicine for RAS detection is very low. Using Captopril test is possible to detect enhanced modification on the shape of renogram due to Angiotensin Converting enzyme inhibition.
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PMID:[Diagnostic imaging in renal vascular diseases: old and new ways. Role of nuclear medicine]. 141 90

This study evaluates the prognostic value of captopril renal scintigraphy in hypertensive patients undergoing renal artery revascularization. Preoperative studies of 51 patients were correlated with blood pressure results at 6- and 12-mo follow-up. Captopril-renal scintigraphy was carried out 1 hr after oral administration of 50 mg of captopril, using either 220 MBq of 99mTc-DTPA or 74 MBq of 99mTc-MAG3, followed by a baseline study in case of abnormal results. Evidence of amelioration or normalization in relation to captopril study was considered predictive of blood pressure control following treatment. Blood pressure response was favorable in 37 patients, but failed to show any improvement in 14. The scintigraphic test was positive in 33 patients (15 cured, 17 improved, 1 failed) and negative in 18 (3 cured, 2 improved, 13 failed). Sensitivity and specificity for renovascular hypertension was 86.5% and 93%, respectively. For blood pressure cure and improvement, the test had positive and negative predictive values of 97% and 72%, respectively. A positive preoperative captopril renal scintigraphic result is a strong predictor of hypertension curability by renal artery revascularization.
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PMID:Prognostic value of captopril renal scintigraphy in renovascular hypertension. 143 71

The effectiveness of single-dose captopril test (CP-T) and captopril renal scintigraphy with 99mTc-DTPA (CP-RG) in the diagnosis of renovascular hypertension (RVH) was evaluated in 27 patients with (Group I, 16 patients) or without (Group II, 11 patients) renal vascular disease. Group I consisted of RVH in 8 patients (bilateral in 3, unilateral in 5), arteriovenous malformation in 3, renal artery aneurysm in 4, including 2 with essential hypertension, and asymptomatic renal artery stenosis in 1. Group II consisted of 6 hypertensive patients (2 with essential hypertension and 4 with renal hypertension) and 5 normotensive patients. Sensitivity of CP-T and CP-RG in the diagnosis of RVH was 29% (2/7) and 86% (6/7), respectively, indicating the latter was more sensitive than the former. In 3 patients with bilateral RVH, positive response in CP-RG was observed only in the unilateral kidney. Specificity of CP-T and CP-RG was 86% (6/7) and 100% (5/5), respectively in Group I, 100% (8/8) and 83% (5/6), respectively in 16 hypertensive patients. CP-T and CP-RG before and after the treatment of RVH were evaluated in 4 patients. The change of positive response in CP-T and CP-RG into negative after percutaneous transluminal renal angioplasty (PTA) or surgery were found in 3, all followed by a fall in blood pressure, which was not observed in the other patient with positive response after PTA.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Single-dose captopril test and captopril renal scintigraphy in the evaluation of renovascular hypertension]. 143 70

Altogether 16 patients with arterial hypertension (AH) were examined. Of these, 11 were with stenosis of renal arteries, 4 had essential hypertension (EH) and I with nephrogenous parenchymatous AH. To estimate the influence of captopril on the total and separate renal function in patients with and without stenosis of renal arteries and the possibility of the use of the given pharmacological test in the diagnosis of renovascular hypertension (RVH), all the patients underwent renal scintigraphy with 99Tc-DTPA on admission to the hospital and 1-7 days after a single intake of 25 mg captopril per os. Later on in the operated patients the results of the test were compared with the hypotensive effect of the surgery. The rate of glomerular filtration (RGF) was measured according to the Gates method. In patients with stenosis of renal arteries and EH, the total filtration renal function remained unchanged after the intake of a single dose of captopril. In patients with stenosis of renal arteries, there was a significant decrease of the RGF on the side of stenosis made for by an insignificant elevation of the RGF in the contralateral kidney, which was accompanied by an increase of asymmetry of the renograms. In patients with no hypotensive effect of the surgery, the test with captopril was negative, which supports the possibility of this test application in the diagnosis of RVH.
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PMID:[Renal scintigraphy with captopril in the diagnosis of renovascular hypertension]. 144 Mar 5

The purpose of this study was to clarify the selectivity and specificity of noninvasive procedures for diagnosis of clinically suspected posttransplant renovascular hypertension. We prospectively investigated 25 renal transplant recipients with arterial hypertension and clinically suspected stenosis of the graft artery (8 female and 17 male patients; ages 45 +/- 15 years). We performed a captopril test with 25 mg captopril (n = 25), renography with technetium-99m diethylene triamine penta-acetic acid (99mTc-DTPA) before and after angiotensin-converting enzyme (ACE) inhibition with determination of glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) (n = 23) and color-coded duplex ultrasonography of the transplant kidney vessels (n = 24). Renal transplant artery stenosis (RTAS) was excluded by renal arteriography in 20 patients and by operative evaluation or clinical follow-up in 5 patients. We identified 4 patients with RTAS and renovascular hypertension. The noninvasive methods showed the following results (sensitivity/specificity): (1) captopril test: 75%/67%; (2) renography combined with ACE-inhibition: 75%/84%; and (3) color-coded duplex ultrasonography: 100%/75%. We conclude that in patients with clinical evidence of RTAS most noninvasive diagnostic procedures are not sufficiently accurate to exclude the diagnosis. Only color-coded duplex ultrasonography did not fail to detect all patients with RTAS and may act as a screening test. Intraarterial renal angiography remains the most reliable and as-yet indispensable diagnostic test for transplant recipients to rule out RTAS.
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PMID:Noninvasive procedures for diagnosis of renovascular hypertension in renal transplant recipients--a prospective analysis. 144 Aug 54

Hemodynamic changes of lesser circulation were investigated in 108 patients with diabetic nephroangiopathy. They were also given vitamin E therapy (8 micrograms/kg of body mass) for 2 weeks to correct metabolic derangements and indices of pulmonary hemodynamics. Partial renal function was determined with 131I-hippuran and 99mTc-DTPA renoscintigraphy. Pulmonary hemodynamics was assessed with pulmonary scintigraphy (MAA 99mTc). The results have shown that vascular renal lesions in diabetes mellitus cause hypertension of lesser circulation and disorders in pulmonary microcirculation, and disorders of lipid metabolism and activation of lipid peroxidation (LPO) progress with augmentation of severity of disease. Vitamin E therapy improves pulmonary hemodynamics, lipid metabolism and LPO. Antioxidant correction was most effective at the initial stages of diabetic nephroangiopathy.
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PMID:[Disorders of pulmonary hemodynamics in patients with diabetic nephroangiopathy and its correction with antioxidants]. 151 66

Renal uptake of Tl-201 reflects renal perfusion and may have a role in defining renal asymmetry in patients with hypertension who are referred for myocardial scintigraphy. The authors compared two methods of quantitating differential renal uptake of Tl-201, with similar data obtained from the angiographic and renal uptake (RU) phases of Tc-99m DTPA scintigraphy in 35 patients with hypertension. For Tl-201, asymmetry in renal counts was quantitated based on a simple outline technique or on interpolative background subtraction of 5-minute posterior images. Inter-observer and intra-observer variability among duplicate measurements were lower for Tl-201, particularly with interpolative background subtraction, than for Tc-99m DTPA. Renal/background ratios were similar for Tl-201 and RU-phase Tc-99m DTPA images when considering liver, spleen, or inter-renal regions as background; however, paraspinal uptake was relatively higher with Tl-201 (P less than 0.01). Qualitatively, renal asymmetry scores with the two radiotracers agreed (r = 0.89, blinded readings by four observers), although asymmetry was more marked with Tl-201 (P = 0.06). Measurements with Tl-201 agreed with both phases of Tc-99m DTPA (r = 0.96 to 0.98), but interpolative background subtraction systematically yielded greater inter-renal asymmetry than RU (P less than 0.01), reflecting the qualitative impression. Thus, ancillary Tl-201 imaging reflects differences between the kidneys in a fashion similar but not identical to Tc-99m DTPA scintigraphy.
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PMID:Comparison of Tl-201 renal uptake with Tc-99m DTPA angiorenography in patients with hypertension. Measures of renal asymmetry. 161 39


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