sodium-pertechnetate-tc-99m and Hypertension

Radionuclide ventriculography has been used for the assessment of left ventricular diastolic function in hypertension. Compared to cardiac Doppler ultrasound techniques, the radionuclide method offers the advantages of allowing numerous consecutive cardiac cycles to be examined, and of deriving the data of these examinations from automated software computer programs. For better precision, however, adequate instrumentation is required. In addition, correction factors should be applied to overcome the influence of elements such as heart rate, left ventricular end-diastolic volume, as well as the technical influence of the efficiency of counting among individuals. Its application to hypertensive patients enabled the diagnosis of early abnormalities of left ventricular filling rate in about 30% of the population studied before any alteration in indices of systolic function were detected. The mechanism of the alteration of these indices of diastolic filling rate in hypertension, however, is still not well understood.

Topics: Cardiac Volume; Diastole; Gated Blood-Pool Imaging; Hemodynamics; Humans; Hypertension; Sodium Pertechnetate Tc 99m; Technetium Tc 99m Aggregated Albumin; Ventricular Function, Left

In recent years, there has been increased recognition of the relative importance of abnormalities of diastolic function in patients with essential hypertension. Indeed, diastolic dysfunction may be the earliest indicator of hypertensive heart disease. In this article, the mechanisms governing normal ventricular relaxation and the factors that may cause diastolic dysfunction are reviewed. Noninvasive clinical methods, particularly Doppler echocardiography and radionuclide angiography, for determination of diastolic function are outlined, and the limited experience in the management of hypertensive patients with abnormalities of diastolic function is discussed. When congestive heart failure develops in a patient with hypertension, it is especially important to determine whether it is due primarily to systolic or to diastolic left ventricular dysfunction.

Topics: Adrenergic beta-Antagonists; Blood Pressure; Calcium Channel Blockers; Diastole; Echocardiography; Heart Failure; Heart Rate; Heart Ventricles; Humans; Hypertension; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Stroke Volume

To study effects of antihypertensive therapy with bisoprolol and actovegin on cerebral perfusion in patients with metabolic syndrome.. Thirty patients (18 women and 12 men) with metabolic syndrome and mild arterial hypertension took bisoprolol alone in a dose 5-10 mg/day, and fifteen patients received combined therapy (bisoprolol and actovegin) for 12 weeks. Before the study and 12 weeks later measurements were made of carbohydrate and lipid metabolism, single photon emission computed tomography investigated brain perfusion.. Improvement of brain perfusion was observed after both monotherapy with bisoprolol and its combination with actovegin.. Monotherapy with bisoprolol and bisoprolol combination with actovegin improved brain perfusion but the combination was more effective.

Topics: Adult; Antihypertensive Agents; Bisoprolol; Brain; Carbohydrate Metabolism; Cerebrovascular Circulation; Drug Therapy, Combination; Female; Follow-Up Studies; Heme; Humans; Hypertension; Lipid Metabolism; Male; Metabolic Syndrome; Middle Aged; Sodium Pertechnetate Tc 99m; Time Factors; Tomography, Emission-Computed, Single-Photon; Treatment Outcome

To examine cerebral perfusion in patients with dyscirculatory encephalopathy and residual disorders of cerebral circulation in arterial hypertension.. Duplex scanning of extra- and intracranial arteries, computed tomography of the head were performed in 26 hypertensive patients with chronic vascular pathology of the brain. Cerebral perfusion was studied by the evidence obtained at single-photon emission computed tomography.. Impaired segmental perfusion of the brain, primarily of frontal and temporal location, was detected in 88.5% patients. Occlusive lesions of extra- and intracranial arteries were accompanied by significant deterioration of the perfusion while visualization of leukoaraosis was associated with high perfusion in the anterior frontal compartments indirectly pointing to defects in autoregulation of cerebral circulation. It was found that different correlations exist between perfusion of various segments of the brain and systemic arterial pressure. This is explained by functional and hemodynamic heterogenicity of different brain regions.. Specific features of cerebral perfusion in patients with chronic forms of vascular brain pathology should be considered in planning antihypertensive therapy because of the risk of focal hypoxia and even ischemia in an inadequate fall of arterial pressure.

Topics: Aged; Antihypertensive Agents; Blood Pressure; Brain; Brain Damage, Chronic; Brain Mapping; Cerebrovascular Circulation; Female; Humans; Hypertension; Male; Middle Aged; Sodium Pertechnetate Tc 99m; Tomography, Emission-Computed, Single-Photon

Thyroid hemiagenesis is a very infrequent abnormality. We present a case of Graves disease associated to a congenital hemiagenesis of the thyroid gland. The thyroid scintigraphy, ultrasonography and laboratory analysis (that showed the existence of thyroid hyperfunction and the present of thyroid stimulating antibodies) were decisive in the diagnosis.

Topics: Atrophy; Autoimmune Diseases; Graves Disease; Humans; Hypertension; Immunoglobulins, Thyroid-Stimulating; Kidney; Male; Middle Aged; Radionuclide Imaging; Radiopharmaceuticals; Sodium Pertechnetate Tc 99m; Thyroid Gland; Thyroid Hormones; Ultrasonography

We analyzed the relationship between regional severity of emphysema, which was evaluated by three-dimensional fractal analysis (3D-FA) of Technegas SPECT images, and coronary heart disease (CHD). For 22 patients with emphysema who underwent Technegas SPECT, we followed up CHD events. The follow-up period was 5.4+/-0.5 (mean +/- SD) years. We defined the upper-lung fractal dimension (U-FD) and lower-lung fractal dimension (L-FD) obtained with 3D-FA of Technegas SPECT images as the regional severity of emphysema. FD became greater with the progression of emphysematous change. During the follow-up period, CHD events occurred in 6 (27%) of the 22 patients. The ratio of U-FD to L-FD for patients with CHD events (0.87+/-0.22) was significantly smaller than for patients without CHD events (1.52+/-0.38) (p = 0.0015). These findings suggest that severer emphysema in the lower lung indicates a higher risk of CHD than that in the upper lung.

Topics: Aged; Coronary Disease; Data Interpretation, Statistical; Emphysema; Female; Fractals; Humans; Hypertension; Lung; Male; Predictive Value of Tests; Respiratory Function Tests; Risk Factors; Smoking; Sodium Pertechnetate Tc 99m; Tomography, Emission-Computed, Single-Photon

To determine whether acute hypertension (HT) is a risk factor for damage to the blood-brain barrier in carotid angiography with nonionic contrast media.. Anesthetized rats received intravenous injections of technetium-99m-pertechnetate and horseradish peroxidase. Two groups of rats received metaraminol to raise their blood pressure to between 165 and 190 mmHg peak systolic and then received intracarotid injections of saline or iopamidol. Two other groups remained normotensive and received intracarotid injections of saline or iopamidol. Animals were perfused with a fixative solution and their brains removed. Activity of extravasated Tc-99m-pertechnetate was determined to assess blood-brain barrier breakdown. Brains were then sectioned, treated histochemically to visualize extravasated horseradish peroxidase, and ranked visually according to horseradish peroxidase staining.. Extravasation of both tracers was significantly greater in the hypertensive group that received contrast media than in the other three groups.. Acute hypertension potentiates the blood-brain barrier-damaging effects of nonionic contrast media during carotid angiography in rats.

Topics: Acute Disease; Animals; Blood-Brain Barrier; Brain; Carotid Arteries; Histocytochemistry; Horseradish Peroxidase; Hypertension; Injections, Intra-Arterial; Iopamidol; Radionuclide Imaging; Rats; Rats, Sprague-Dawley; Sodium Pertechnetate Tc 99m

The left ventricular function of 14 acromegalic patients was investigated using radionuclide ventriculography. After labeling the red blood cells with 750-1,000 MBq 99mTc-pertechnetate, ECG-triggered left anterior oblique images were recorded. Fourier analysis was then performed on the time-activity curve of the left ventricle. The ejection fraction (EF), peak ejection rate, time to peak ejection (TPE), time to end-systole (TES), peak filling rate (PFR), time to peak filling (TPF), 1/3 EF, 1/3 filling fraction (FF), TPE/T, TPF/T and TES/T values (T: time interval for one heart beat) were calculated for each patient. Five patients (35.7%) had clinical cardiovascular symptoms. A decreased EF was observed in 28.5% of the patients. In comparison to the control group, the EF (53.5 +/- 5.5 vs. 60.8 +/- 5% p less than 0.009), 1/3 EF (14.45 +/- 3 vs. 20 +/- 4%, p less than 0.001), 1/3 FF (28.5 +/- 10.6 vs. 41 +/- 11%, p less than 0.02), TPE (158 +/- 33 vs. 132 +/- 35 ms, p less than 0.01), TPE/T (20.2 +/- 5 vs. 16 +/- 3.7, p less than 0.01) and PFR (2.4 +/- 0.5 vs. 2.9 +/- 0.4 EDC/s, p less than 0.005) were significantly different. It was found that TPE was prolonged and the early ejection function was decreased. Diastolic dysfunction was found in 5 (35.7%) patients; 21.4% of the patients had decreased PFR values although they had no cardiac symptom, hypertension and/or cardiomegaly. Scintigraphic parameters did not correlate with the presence of hypertension, cardiomegaly or cardiovascular symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Acromegaly; Adult; Cardiomegaly; Erythrocytes; Female; Gated Blood-Pool Imaging; Humans; Hypertension; Male; Myocardial Contraction; Sodium Pertechnetate Tc 99m; Ventricular Function, Left

A method of assessing relative changes in the head blood content under the influence of medicines is described. The method is based on an analysis of deviations of the equilibrium part of the radioactivity curve recorded with the aid of gamma-scintigraphy and injection in the form of bolus of the radiopharmaceutical agent 99mTc-pertechnetate to the ulnar vein. Changes in the blood content under the influence of nitroglycerin, duzodril, adalate and cavinton were examined in 37 patients suffering from dyscirculatory encephalopathy.

Topics: Aged; Cerebrovascular Circulation; Cerebrovascular Disorders; Chronic Disease; Drug Evaluation; Gamma Cameras; Humans; Hypertension; Intracranial Arteriosclerosis; Middle Aged; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Time Factors; Vasodilator Agents; Vasomotor System

To evaluate the effects of long-standing systemic hypertension on left ventricular (LV) function during daily activities, ambulatory radionuclide monitoring of LV ejection fraction (EF) and blood pressure was performed during exercise and other structured activities in 31 hypertensive patients. Patients were divided into 3 groups based on the absence of LV hypertrophy (group 1 [n = 16], LV mass 107 +/- 12 g/m2), presence of LV hypertrophy without electrocardiographic changes (group 2 [n = 10], LV mass 141 +/- 8 g/m2) and LV hypertrophy with associated electrocardiographic changes (group 3 [n = 5], LV mass 158 +/- 9 g/m2). The groups were similar with respect to age, baseline medication, treated and untreated blood pressure, resting EF and treadmill exercise time. Patients in group 3 had the longest history of hypertension. Peak filling rate was normal in group 1 (2.9 +/- 0.4 end-diastolic volume/s), but reduced at rest in groups 2 (2.4 +/- 0.4) and 3 (2.1 +/- 0.3). Patients in group 1 had normal EF responses to exercise and mental stress testing, as well as during routine ambulatory activities. Patients in group 2 had a blunted EF response to exercise, and those in group 3 had a significantly abnormal response. Both group 2 and 3 patients demonstrated abnormal EF responses to mental stress, as well as cold pressor testing in association with significant increases in mean arterial pressure and marked reduction in diastolic filling rate. Decreases in EF were also observed during routine patient monitoring in 3 group 3 patients and 4 group 2 patients. These events were associated with significantly increased blood pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adult; Ambulatory Care; Cardiomegaly; Cold Temperature; Echocardiography; Electrocardiography; Exercise Test; Humans; Hypertension; Male; Middle Aged; Monitoring, Physiologic; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Stress, Physiological; Stroke Volume; Ventricular Function, Left

The integrity of the blood-brain barrier (BBB) was examined in rabbits, in terms of the partition of 99mTc-pertechnetate (99mTcO4-) between brain and blood, following intracarotid injection of hypertonic arabinose, hypertension (168 mm Hg and 10% inspired carbon dioxide), or hypotension (less than 20 mm Hg for 15 min). Corrections were made for changes in tissue blood contents, using chromium-51 as a red cell marker. In control animals the mean brain:blood ratio was 0.038 (range 0.027-0.052). Following arabinose there was a five-fold increase in mean BBB permeability (mean brain:blood ratio 0.192 (0.070-0.378)). There was no change after hypertension and carbon dioxide (mean ratio 0.034) or after hypotension (mean ratio 0.032), despite an increase in cerebral extracellular potassium. Examination of other tissues showed no change in the 99mTcO4- tissue/blood partition in heart muscle in any study but, following hypotension, ratios in the kidney (mean ratio 1.63) and, to a lesser extent, the liver (mean ratio 1.37) had increased, suggesting an abnormality of active transport under these conditions. We conclude that, while 99mTcO4- tissue/blood partitioning revealed osmotic disruption of the BBB, profound hypotension with evidence of brain cell damage did not change BBB permeability to the same marker. Hypotension may influence active transport of this ion in liver and kidney.

Topics: Animals; Arabinose; Blood-Brain Barrier; Brain Chemistry; Hypertension; Hypertonic Solutions; Hypotension; Rabbits; Sodium Pertechnetate Tc 99m; Tissue Distribution

Differential evaluation was carried out of hypertrophy as a factor possibly of compensatory or that of furthering disturbances of the coronary circulation and contractile function of the myocardium. Echocardiography, radionuclide ventriculography tests with physical loads revealed that only moderate hypertrophy of the left ventricle in IHD patients with hypertensive disease (grade II) may be considered as one of the compensatory factors maintaining the functional state of the left ventricle myocardium.

Topics: Cardiomegaly; Coronary Disease; Echocardiography; Exercise Test; Heart Ventricles; Hemodynamics; Humans; Hypertension; Myocardial Contraction; Radionuclide Imaging; Sodium Pertechnetate Tc 99m

A rare case of struma ovarii producing hyperthyroidism in a postmenopausal woman is reported. The ovarian tumor demonstrated uptake of both [99mTc]pertechnetate and 131I, allowing preoperative diagnosis of the condition. In females with unexplained hyperthyroidism and low 131I uptake by the cervical thyroid gland, imaging of the pelvis should be considered.

Topics: Aged; Aged, 80 and over; Female; Humans; Hypertension; Iodine Radioisotopes; Menopause; Ovarian Neoplasms; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Struma Ovarii

Left ventricular diastolic filling measurements were determined by means of standard consecutive R-wave gating, list mode acquisition, and alternate R-wave gating. Time-activity curves obtained by the latter two methods were equally accurate in quantifying rapid, slow, and atrial left ventricular filling, whereas curves obtained by means of standard gating were inadequate for this purpose.

Topics: Cardiomegaly; Coronary Artery Disease; Diastole; Electrocardiography; Heart Ventricles; Humans; Hypertension; Male; Middle Aged; Myocardial Contraction; Radionuclide Angiography; Sodium Pertechnetate Tc 99m; Stroke Volume; Time Factors

Topics: Adult; Heart Function Tests; Heart Ventricles; Humans; Hypertension; Middle Aged; Myocardial Contraction; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Ultrasonography

The state of the cerebral blood flow in essential hypertension has been studied in relation to various clinical and hemodynamic parameters. The authors emphasize that the regulation of the cerebral blood flow depends to a great degree on the level of the systolic and pulse pressure as well as on the type of hemodynamics.

Topics: Adult; Aged; Blood Pressure; Cardiac Output; Cerebrovascular Circulation; Combined Modality Therapy; Humans; Hypertension; Middle Aged; Pulse; Sodium Pertechnetate Tc 99m; Xenon Radioisotopes

There has been recent interest in using nondiuretic drugs as initial antihypertensive therapy. Therefore, a study was designed to compare the efficacy and the effects on left ventricular function of hydrochlorothiazide, propranolol and prazosin in 13 patients with mild to moderate hypertension. After a 4-week washout period, patients were treated serially with each drug in a randomized order for 2 months each. Dosages were titrated until the patient showed a sitting diastolic blood pressure less than or equal to 90 mm Hg or to a maximum dosage of 100 mg/day of hydrochlorothiazide, 320 mg of propranolol and 20 mg of prazosin. Blood pressure was measured, plasma catecholamine concentrations were assayed and radionuclide determinations of rest and exercise left ventricular function and volume were made at the end of each period as well as after a second 1-month washout period at the end. In the sitting and standing positions, systolic and diastolic blood pressure control was equivalent for all 3 drugs. Goal blood pressure was achieved in 10 of 13 patients receiving hydrochlorothiazide, in 8 of 12 receiving propranolol and in 9 of 13 on prazosin. Importantly, 3 of 4 patients not controlled with prazosin, 5 of 6 uncontrolled with propranolol and 2 of 3 whose blood pressure was not reduced by hydrochlorothiazide were controlled when receiving 1 of the other medications. None of the drugs changed rest or exercise ejection fraction or volume, and side effects were minimal.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adult; Aged; Blood Pressure; Erythrocytes; Female; Heart; Heart Rate; Humans; Hydrochlorothiazide; Hypertension; Male; Middle Aged; Physical Exertion; Posture; Prazosin; Propranolol; Quinazolines; Radionuclide Imaging; Random Allocation; Sodium Pertechnetate Tc 99m; Stroke Volume; Technetium

Topics: Adult; Cardiac Output; Cardiography, Impedance; Computers; Female; Humans; Hypertension; Male; Middle Aged; Plethysmography, Impedance; Serum Albumin; Sodium Pertechnetate Tc 99m; Technetium