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Results 501 - 550 of 703
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Howard P A - - 1991
An intravenous form of dipyridamole has been approved for cardiac stress testing with thallous chloride Tl 201 (201Tl) imaging. The procedure provides an alternative method for stress testing of patients who cannot perform strenuous physical exercise because of physical limitations or those in the immediate postinfarction period. Dipyridamole simulates the ...
Crawford M H - - 1991
Exercise testing early after myocardial infarction has been shown to be of further risk stratification value among otherwise low-risk patients on the basis of an uncomplicated clinical course. The addition of cardiac imaging modalities to exercise testing has augmented this capacity. Exercise echocardiographic imaging before and immediately after treadmill exercise ...
Heller G V - - 1991
This study was performed to evaluate the presence of angina pectoris, electrocardiographic changes and reversible thallium-201 defects resulting from 2 different levels of exercise in 19 patients with known coronary artery disease and evidence of exercise-induced ischemia. The exercise protocols consisted of a symptom-limited incremental exercise test (Bruce protocol) followed ...
Seldin D W - - 1991
Myocardial perfusion studies continue to be a major focus of research, with new investigations of the relationship of exercise-redistribution thallium imaging to diagnosis, prognosis, and case management. The redistribution phenomenon, which seemed to be fairly well understood a few years ago, is now recognized to be much more complex than ...
Stern S - - 1991
To determine the effect of different types of exercise supplementation on dipyridamole thallium image quality, 78 patients were prospectively randomized to one of three protocols: dipyridamole infusion alone, dipyridamole supplemented with isometric handgrip, and dipyridamole with low-level treadmill exercise. Heart-to-lung, heart-to-liver, and heart-to-adjacent infradiaphragmatic activity ratios were generated from anterior ...
DePuey E G - - 1991
The substitution of intravenous dipyridamole for symptom-limited treadmill exercise has provided a non-invasive means to diagnose coronary artery disease with 201Tl scintigraphy in patients unable to adequately exercise. Limitations of dipyridamole/thallium imaging are primarily due to suboptimal image quality secondary to hepatic tracer concentration and decreased test sensitivity in patients ...
Gibson R S - - 1991
In asymptomatic patients, the use of exercise ECG testing for the detection of subclinical coronary artery disease has considerable theoretical appeal, but its practical application is severely hampered by the constraints of Bayes' theorem. Serial exercise ECGs do not appear to offer significant improvement in this regard. Thallium-201 perfusion scintigraphy ...
Krivokapich J - - 1991
Positron emission tomography has been employed in vivo to assess flow using N-13 (nitrogen-13) ammonia and glucose metabolism, with the glucose analog F-18 (fluorine-18) fluorodeoxyglucose. Flow metabolism mismatches in which glucose metabolism is increased with respect to flow have been used to define ischemic, but viable myocardium. The feasibility of ...
Verani M S - - 1991
Pharmacologic coronary vasodilation as an adjunct to myocardial perfusion imaging has become increasingly important in the evaluation of patients with coronary artery disease, in view of the large number of patients who cannot perform an adequate exercise test or in whom contraindications render exercise inappropriate. Adenosine is a very potent ...
Pirelli S - - 1991
The present study compares the relative usefulness of the maximal treadmill exercise electrocardiography test with the high-dose dipyridamole echocardiography test (echocardiographic monitoring during dipyridamole infusion up to 0.84 mg/kg in 10 minutes) in detecting severe restenosis or coronary artery disease progression (greater than 70% stenosis) in asymptomatic patients 12 months ...
Mahmarian J J - - 1991
Exercise thallium-201 perfusion scintigraphy has been used extensively over the last decade for the detection and localization of coronary artery disease. Single-photon emission computed tomography (SPECT) is a refinement of presently available techniques, offering improved identification over planar imaging of individual vessel stenosis and quantification of the extent of abnormally ...
Sigal S L - - 1991
Fifty-two paired stress/delayed planar 201TI studies (27 exercise studies, 25 dipyridamole studies) were processed twice by seven technologists to assess inter- and intraobserver variability. The reproducibility was inversely related to the size of 201TI perfusion abnormalities. Intraobserver variability was not different between exercise and dipyridamole studies for lesions of similar ...
Pirelli S - - 1991
Recently, we have shown the usefulness of high-dose dipyridamole echocardiography testing (DET) as an exercise-independent method for the evaluation of patients having coronary angioplasty. The purpose of the present study was to determine the value of DET compared with exercise testing in the early functional evaluation after successful percutaneous transluminal ...
Severi S - - 1991
Observational data prospectively collected permit the examination of a complex set of decisions, including the decision not to perform any stress testing. Patients with or without previous myocardial infarction admitted for coronary evaluation and not submitted to any stress testing because of clinical reasons are at a higher risk for ...
Cordes M - - 1991
[123I]IBZM is a new radioactive labelled ligand which has a high affinity and specificity to D2-dopamine receptors. The in vivo kinetics of [123I]IBZM were studied in patients with unilateral and bilateral accentuated idiopathic Parkinson's disease. The uptake in the basal ganglias and the imaging properties of this D2 receptor antagonist ...
Whitfield S - - 1991
To determine how frequently new wall-motion abnormalities that are indicative of ischemia accompany thallium redistribution, 47 consecutive patients underwent two-dimensional echocardiography during routine dipyridamole-thallium stress testing. A secondary aim of the study was to determine whether the addition of isometric handgrip exercises to the standard dipyridamole imaging protocol increased the ...
Aoki M - - 1991
A noninfarcted, entirely collateral-dependent myocardial region provides an opportunity to assess the effect of nitroglycerin on coronary collateral function during exercise. Stress thallium-201 computed tomography was performed in seven patients with effort angina and no history of myocardial infarction, both before and after nitroglycerin (0.3 mg). All patients had single-vessel ...
Coyne E P - - 1991
Adenosine is an endogenously produced compound that has significant effects as a coronary and systemic vasodilator. Previous studies suggest that intravenous infusion of adenosine, coupled with thallium-201 scintigraphy, may have specific value as a noninvasive means of evaluating coronary artery disease. The purpose of this study was to compare the ...
Giubbini R - - 1991
The purpose of the present study was to determine whether and to what extent mental stress can reproduce the perfusion defects that are known to be induced by exercise. Twenty-four patients with recent myocardial infarction (New York Heart Association functional class I) and evidence of ischemic response were evaluated by ...
Lattanzi F - - 1991
BACKGROUND: Dipyridamole echocardiography test (DET: two-dimensional echocardiographic monitoring with dipyridamole infusion up to 0.84 mg/kg in 10 minutes) is a useful tool for the noninvasive diagnosis of coronary artery disease. Aims of the present study were to assess the effects of antianginal drugs on dipyridamole-induced ischemia and to evaluate whether ...
Pollock S G - - 1991
PURPOSE: The aim of this study was to (1) determine whether nonimaging variables add to the diagnostic information available from exercise thallium-201 images for the detection of multivessel coronary artery disease; and (2) to develop a model based on the exercise thallium-201 stress test to predict the presence of multivessel ...
Pijls N H - - 1991
BACKGROUND: In the setting of percutaneous transluminal coronary angioplasty (PTCA), immediate information about the result of the intervention is important, whereas morphological parameters are often less reliable than in diagnostic coronary arteriography. Recently, a new videodensitometric method was introduced and validated in animal experiments, which allows accurate comparison of maximal ...
Pozzoli M M - - 1991
To compare the relative diagnostic value of exercise echocardiography with perfusion technetium-99m metoxyisobutylisonitrile single-photon emission computed tomography (SPECT) in detecting coronary artery disease (CAD), 75 patients with suspected CAD but a normal electrocardiogram (ECG) at rest were included in a prospective correlative study. Both the exercise echocardiograms and SPECT studies ...
Whalley D R - - 1991
Three dose administration protocols for 99Tcm-MIBI were applied to groups of 15 patients with known or suspected ischaemic heart disease. Firstly, injections were given on consecutive days, with 300 MBq at rest and 500 MBq 24 h later at exercise. Secondly, both injections on the same day with 200 MBq ...
Mazeika P K - - 1991
This article deals with the application of pharmacological stress echocardiography, a relatively new and evolving technique, to the diagnosis and assessment of patients with coronary artery disease. The value of echocardiography in ischaemic heart disease is initially outlined, followed by a brief review of the exercise two-dimensional echocardiography and exercise ...
LaManna M M - - 1990
Fifteen patients at a mean age of 58 underwent adenosine and maximal exercise thallium SPECT imaging. All scans were performed 1 week apart and within 4 weeks of cardiac catheterization. SPECT imaging was performed after the infusion of 140 micrograms/kg/min of adenosine for 6 minutes. Mean heart rate increment during ...
Lambertz H - - 1990
The diagnostic use of exercise echocardiography has been widely reported. However, transthoracic exercise echocardiography is inadequate in up to 20% of patients because of poor image quality related to exercise. In an attempt to overcome these limitations, a system was developed in which transesophageal echocardiography is combined with simultaneous transesophageal ...
Hendel R C - - 1990
Technetium-99m-labeled agents have advantages over thallium-201 in terms of photon statistics, cost and clinical availability. They have been suggested as an alternative to thallium for myocardial perfusion imaging. Teboroxime is a new boronic acid adduct of technetium dioxime (BATO) compound that demonstrates favorable characteristics in preliminary studies. With use of ...
Krivokapich J - - 1990
This study was designed to test the usefulness of nitrogen-13 (N-13) glutamate imaging with positron emission tomography in defining myocardial ischemia in humans. Seventeen patients who had undergone coronary arteriography were studied with N-13 glutamate at peak supine exercise using a bicycle ergometer, as well as with the flow tracer ...
Jones R H - - 1990
New radiopharmaceuticals permit simultaneous assessment of myocardial perfusion and left ventricular function using a single tracer injection. The purpose of this study was to quantitate the relation between myocardial perfusion and function at rest and during exercise in patients with documented coronary artery disease (CAD). A rest first-pass radionuclide angiocardiogram ...
Rockett J F - - 1990
Dipyridamole TI-201 imaging is an ideal alternative to exercise TI-201 scintigraphy in patients who are unwilling or unable to perform maximum exercise stress. The use of intravenous dipyridamole, alone or in combination with exercise, has not been approved for clinical practice by the Food and Drug Administration. Once approval is ...
Niemeyer M G - - 1990
STUDY OBJECTIVE: The aim was to evaluate discriminant analysis, performed in patients without prior myocardial infarction, in enhancing the diagnostic value of quantitative exercise 201thallium scintigraphy. DESIGN: All clinical, electrocardiographic, and scintigraphic variables were first subjected to a univariate analysis. Afterwards a discriminant analysis was done. PATIENTS: 135 patients (104 ...
Lette J J Department of Medicine, Maisonneuve-Rosemont Hospital, Montreal, - - 1990
The extent of jeopardized myocardium can be underestimated on stress thallium myocardial perfusion images when exercise tolerance is limited by angina pectoris. A patient's tolerance for pain can influence the degree of myocardial ischemia observed on myocardial perfusion images during effort angina. A case is reported of a patient with ...
Segall G M - - 1990
Whole-body thallium scintigraphy can be used to diagnose and evaluate occlusive arterial disease in patients with leg claudication. We performed exercise and redistribution scans in 36 healthy individuals and 17 patients with claudication. Regions of interest were drawn around the whole body, as well as each buttock, thigh, and calf. ...
Jain A - - 1990
Thrombolytic therapy has become the treatment of choice for patients with acute myocardial infarction. Researchers are not yet able to identify patients with salvage of myocardium who are at risk for recurrent coronary events. Thus, a prospective trial was performed in 46 patients with myocardial infarction (28 anterior and 18 ...
van der Watt F J FJ Department of Surgery, Universitas Hospital, - - 1990
ECG-monitored exercise testing has been proposed as a relatively inexpensive and effective means of screening for asymptomatic coronary artery disease in patients presenting for peripheral vascular surgery. Despite the fact that exercise thallium scintigraphy is also dependent on the patient's ability to exercise, using this test in conjunction with ECG-monitored ...
Dilsizian V - - 1990
BACKGROUND: The identification of ischemic but viable myocardium by thallium exercise scintigraphy is often imprecise, since many of the perfusion defects that develop in ischemic myocardium during exercise do not "fill in" on subsequent redistribution images. We hypothesized that a second injection of thallium given after the redistribution images were ...
Zdrenghea D - - 1990
Dipyridamole-exercise ECG test (DET) was found to present a greater sensitivity than exercise or dipyridamole ECG test alone in detecting ischemic heart disease (IHD). A group of 39 patients with probable IHD and negative exercise test was investigated by i.v. dipyridamole administration. Eight subjects presented significant ECG changes. The remaining ...
Gasperetti C M - - 1990
The prevalence of silent myocardial ischemia was prospectively assessed in a group of 103 consecutive patients (mean age 59 +/- 10 years, 79% male) undergoing symptom-limited exercise thallium-201 scintigraphy. Variables that best correlated with the occurrence of painless ischemia by quantitative scintigraphic criteria were examined. Fifty-nine patients (57%) had no ...
Campeau R J - - 1990
Pectoralis muscle uptake of thallium-201 was noted in 8 (73%) out of 11 patients after exercise arm ergometry. Uptake varied from mild to marked and potentially could be confused with pulmonary Tl-201 activity with a resulting false-positive diagnosis of exercise-induced left ventricular dysfunction. The three patients exhibiting negative or trace ...
Paridon S M - - 1990
Eleven patients underwent exercise testing after operative repair of anomalous origin of the left coronary artery from the pulmonary artery. Five patients repaired after 2 years of age comprised a childhood surgery group, and six patients repaired before 2 years of age comprised an infant surgery group. All patients were ...
Sheikh K H - - 1990
To assess the relation of quantitative measures of coronary stenoses to the development of exercise-induced regional wall motion abnormalities, 34 patients with isolated, single vessel coronary artery lesions and normal wall motion at rest underwent exercise echocardiography and quantitative angiography on the same day. Although all 11 patients with a ...
Aoki M - - 1990
To clarify the incidence and clinical characteristics of exercise-induced myocardial ischemia in patients with vasospastic angina, we performed exercise thallium computed tomography in 25 patients who had no significant coronary artery stenosis greater than 70%. Coronary artery spasm was documented by coronary angiography in all patients. Eleven patients (44%) developed ...
Fleg J L - - 1990
Although a silent ischemic electrocardiographic response to treadmill exercise in clinically healthy populations is associated with an increased likelihood of future coronary events (i.e., angina pectoris, myocardial infarction, or cardiac death), such a response has a low predictive value for future events because of the low prevalence of disease in ...
Hassan I M - - 1990
To study the potential usefulness of 99mTc-methoxy isobutyl isonitrile (99mTc-MIBI) as a substitute for 201Tl in assessing patients with ischaemic heart disease, 24 patients underwent 1 day rest and exercise 99mTc-MIBI single photon emission computerised tomography (SPECT) 1 week after SPECT exercise 201Tl. All patients were catheterized within 1 month ...
Paridon S M - - 1990
For a study of the natural history of coronary artery lesions after Kawasaki disease and their effect on myocardial blood flow reserve with exercise, five such patients underwent exercise testing on a bicycle. Oxygen consumption, carbon dioxide production, minute ventilation, and electrocardiograms were monitored continuously. Thallium-201 scintigraphy was performed for ...
Najm Y C - - 1990
The evaluation of technetium-99m methoxy isobutylisonitrile for the diagnosis of coronary artery disease requires comparative validation against thallium-201, the established perfusion imaging agent. We have compared myocardial and lung uptake of both radiotracers following maximal exercise in 52 patients: 40 with angiographically proven coronary disease. Qualitative and quantitative image analysis ...
Hurwitz G A - - 1990
Although dipyridamole can be used with myocardial scintigraphy to demonstrate reversible perfusion defects, combining exercise with the pharmacologic tool could improve image quality and information yield. The incidence of perfusion defects and the quality of thallium 201 images were reviewed in a series of 820 patients who had been assigned ...
Nordrehaug J E - - 1989
The effects of heart rate on the myocardial uptake and clearance of 201Tl were studied prospectively in seven healthy men, mean age 43 +/- 7 (s.d.) yr. Initial and delayed (3 hr) thallium images were obtained in three views after three bicycle exercise tests: to maximal, 80% and 60% of ...
Siffring P A - - 1989
Pharmacologic stress testing with dipyridamole is useful in patients undergoing thallium-201 myocardial perfusion scintigraphy who cannot adequately exercise. Because dipyridamole increases coronary blood flow by reducing the metabolism of adenosine, the authors compared the uptake and clearance of T1-201 following exercise stress testing (EST) and resting intravenous infusion of adenosine ...
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