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Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

After a 4 minute i.v. dipyridamole infusion (0.14 mg/Kg/min) serial Thallium-201 scans were obtained in 45 patients, without myocardial necrosis, undergoing coronarography. Twelve patients had effort angina, 6 rest angina, 14 effort associated with rest angina, 13 had atypical chest pain. Thirty-two patients had a 50% or greater stenosis of 1 or more coronary artery (8 had three vessels disease, 7 two vessels, 17 one vessel); 13 patients had no significant coronary stenosis ("control group"). The test induced electrocardiographic signs of ischemia in 18 patients, all with significant coronary stenosis, 15 of them experienced angina too. Sensitivity of Thallium-201 for detecting coronary artery stenosis was 94% (30 of 32) and specificity was 85% (11 of 13). In the group of the 17 patients with one vessel disease we obtained a sensitivity and specificity of 100% (17 of 17). We conclude that Thallium-201 myocardial imaging after pharmacologic vasodilatation with dipyridamole is a highly sensitive and specific test for detecting coronary artery stenoses without necessary overt ischemia. In fact dipyridamole, as consequence of its important coronary vasodilatation, produces differences in myocardial perfusion with relative perfusion defects detectable with Thallium-201 imaging.
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PMID:[Assessment of coronary stenosis by myocardial scintigraphy with thallium-201 after dipyridamol infusion]. 405 90

Twenty-six patients with known benign coronary anatomic characteristics and atypical chest pain syndromes were evaluated for the possibility of coronary spasm. Incremental intravenous ergonovine maleate infusions were administered, and thallium-201 scintigraphy was performed at the peak dosage and during recovery in the coronary care unit. With ergonovine therapy, 4 patients (16%) had chest pain associated with electrocardiographic (ECG) or scintigraphic changes. Nine patients (35%) had chest pain without associated ECG or scintigraphic changes, and 13 patients did not have chest pain in response to ergonovine administration, although 2 (8%) had ergonovine-induced scintigraphic defects. All 4 patients with ergonovine-induced chest pain and associated ECG or scintigraphic abnormalities had resolution or reduction of chest pain after medical treatment. However, 7 of the 9 patients with ergonovine-induced chest pain in the absence of ECG or scintigraphic abnormalities continued to have symptoms despite medical treatment a mean of 18 months later. In this limited study of a select group, bedside ergonovine provocation appeared safe. Many patients had chest pain, but few showed ECG or scintigraphic evidence of ischemia. Perfusion scintigraphy appears to have potential complementary value for the identification of an ischemic cardiac cause of atypical chest pain and provides a rationale for appropriate therapy.
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PMID:Value of noninvasive assessment of patients with atypical chest pain and suspected coronary spasm using ergonovine infusion and thallium-201 scintigraphy. 648 23

The prerequisite in establishing the indication for coronary arteriography is low mortality and morbidity of the procedure. Mortality is about 1%, major complications are myocardial infarction (1.5 to 2%) and cerebral embolism (less than 1%). These low complication rates are generally achieved only in institutions which perform at least 400 procedures per year. Coronary arteriography is indicated in the following groups of patients: patients with angina pectoris aged below 45; patients over 45 with sudden worsening of angina, angina pectoris uncontrolled by medication (impaired quality of life) and cases where there is objective evidence of severe ischemia on exercise though angina is mild; recurrence of angina or positive stress ECG after myocardial infarction; following an episode of unstable angina; following resuscitation due to ventricular fibrillation; suspected Prinzmetal angina; postinfarction aneurysm with signs of heart failure; candidates for valve surgery aged over 45. Coronary arteriography is also performed to evaluate the result of bypass surgery, in patients with unclear diagnosis exposed to occupational hazards, and in acute myocardial infarction (thrombolysis, ventricular septal rupture, acute mitral regurgitation). The main indications for radioisotope studies (Tl-201 myocardial scintigraphy and radionuclide angiography during dynamic exercise) are detection and localization of ischemic zones and scars in patients with known coronary disease, and evaluation of the result of coronary artery bypass surgery. Less frequent indications are, today, atypical chest pain and uninterpretable ECG, and asymptomatic patients with abnormal stress ECG. 2-d echocardiography is the most widely used noninvasive technique for qualitative assessment of regional wall motion disorders at rest. 3800 coronary arteriographies are performed yearly in the public hospitals of Switzerland.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Indications for coronary angiography and other special studies]. 660 28

The association between mitral valve prolapse (MVP) and atypical chest pain has been well-described. Numerous theories have been proposed to explain this association. A number of lines of evidence suggest that underlying ischemia may cause chest pain in some patients with MVP. We have recently evaluated 4 patients with chest pain syndromes who had angiographic evidence of MVP and spasm of angiographically normal coronary arteries. The possibility that coronary spasm is the underlying etiology of chest pain in some patients with mitral valve prolapse raises a theoretical argument against beta-blockade in these patients. Three of our patients were successfully treated with calcium channel blockers.
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PMID:Mitral valve prolapse and spasm of normal coronary arteries: report of four cases and review of the literature. 672 Dec 52

Seven subjects with rate-dependent left bundle branch block (RDLBBB) and 13 subjects with normal conduction (control group) underwent upright bicycle exercise radionuclide angiography to determine the effects of the development of RDLBBB on global and regional left ventricular function. Six of the seven subjects with RDLBBB had atypical chest pain syndromes; none had evidence of cardiac disease based on clinical examination and either normal cardiac catheterization or exercise thallium-201 scintigraphy. Radionuclide angiograms were recorded at rest and immediately before and after RDLBBB in the test group, and at rest and during intermediate and maximal exercise in the control group. The development of RDLBBB was associated with an abrupt decrease in left ventricular ejection fraction (LVEF) in six of seven patients (mean decrease 6 +/- 5%) and no overall increase in LVEF between rest and maximal exercise (65 +/- 9% and 65 +/- 12%, respectively). In contrast, LVEF in the control group was 62 +/- 8% at rest and increased to 72 +/- 8% at intermediate and 78 +/- 7% at maximal exercise. The onset of RDLBBB was associated with the development of asynchronous left ventricular contraction in each patient and hypokinesis in four of seven patients. All patients in the control group had normal wall motion at rest and exercise. These data indicate that the development of RDLBBB is associated with changes in global and regional ventricular function that may be confused with development of left ventricular ischemia during exercise.
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PMID:Effect of rate-dependent left bundle branch block on global and regional left ventricular function. 683 71

To assess the accuracy of serial myocardial perfusion scintigraphy with thallium-201 (201Tl) to predict graft patency early and late coronary artery bypass surgery, rest and exercise 201Tl and coronary arteriography were performed preoperatively and 2 weeks and 1 year after operation. The scintigraphic results were compared with graft patency, symptoms, left ventricular function and physical work capacity in a consecutive series of 55 patients with a total of 154 grafts. Serial 201Tl had an 80% sensitivity, 88% specificity and 86% overall accuracy in detecting or excluding graft occlusion, which was predicted by reversible ischemia as well as persistent "new scar" segments. Occluded grafts were correctly localized by 201Tl scintigraphy in 61%. Postoperative apical 201Tl defects were frequent (two-thirds of cases), and were the result of intraoperative transapical venting of the left ventricle. After coronary bypass graft surgery, ejection fraction at rest was unchanged. Left ventricular end-diastolic pressure and physical work capacity improved significantly. In the presence of new perfusion defects detected postoperatively, physical work capacity was reduced significantly. New 201Tl defects in addition to typical or atypical angina provided a high probability of graft occlusion, while in the absence of new 201Tl defects all grafts were patent in more than 90% of patients, all of whom had no or only atypical chest pain. We conclude that serial 201Tl imaging after coronary artery bypass surgery is an accurate noninvasive method that can be used routinely to assess graft function, to localize spatially occluded grafts and to identify patients with a high likelihood of graft occlusion who may need invasive studies.
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PMID:Accuracy of serial myocardial perfusion scintigraphy with thallium-201 for prediction of graft patency early and late after coronary artery bypass surgery. A controlled prospective study. 698 12

The radioactive isotope thallium 201 behaves physiologically as a potassium analog, and when injected intravenously accumulates rapidly within the cells of many organs. Uptake of the isotope reflects both regional perfusion and sodium-potassium pump activity. The radionuclide emits 80 keV x-rays which are suitable for scintillation camera imaging. The main clinical application of (201)TI scintigraphy has been in myocardial imaging. Abnormal uptake of the isotope results in a cold spot on the myocardial image. In patients with coronary artery disease, the differentiation of ischemic and infarcted myocardium is made by comparing images obtained after injecting the radionuclide at the peak of a maximal exercise test with those obtained after injection at rest. Abnormalities due to ischemia usually are seen only on the stress image whereas fixed defects in both rest and stress studies usually indicate areas of infarction or scarring. Some investigators believe that redistribution images obtained four to six hours after stress injection (without administering further (201)TI) give the same information as a separate rest study. The sensitivity of stress imaging for detecting significant coronary disease is of the order of 80 percent to 95 percent, though computer processing of the images may be necessary to achieve the higher figure. The prediction of the extent of coronary disease from (201)TI images is less reliable. An abnormal (201)TI image is not entirely specific for coronary artery disease and the likelihood of an abnormal image being due to this diagnosis varies according to the clinical circumstances. The main clinical value of (201)TI myocardial imaging is likely to be in the noninvasive screening of patients with atypical chest pain or with ambiguous findings on stress electrocardiographic tests. It has also proved useful in studying patients with variant angina or following a coronary bypass operation. It is doubtful whether the technique is clinically helpful in most patients with suspected or established acute myocardial infarction. Imaging of organs other than the heart with (201)TI has received much less attention but has been reported in patients with peripheral vascular disease and various primary and secondary neoplasms.
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PMID:Thallium 201 scintigraphy. 722 45

Under basal conditions the echocardiographic findings in anginal patients (pts.) without previous myocardial infarction appears usually normal. Consequently, the usefulness of the ultrasounds evaluation in angina pectoris has been commonly considered poor and the utilization of this technique in coronary artery disease has been restricted to the detection of myocardial infarction in its acute phase or to its chronic mechanical alterations. The purpose of this study was to assess the possibility offered by M-mode echocardiography to detect changes caused by transient myocardial ischemia at rest in man, in view of the possible diagnostic application of this technique. The reported results were obtained from 25 ischemic attacks (13 spontaneous and 12 ergonovine induced) with ST segment elevation or pseudonormalization of a basally negative T wave at rest. The semiautomatic computerized analysis of echocardiograms continuously recorded during these attacks showed a reduction of motion and of systolic thickening, accompanied by a diastolic thinning of the wall involved by the ischemia. These changes occur very early: they appear few seconds before ECG changes and are accompanied by a reduction of contraction and relaxation dP/dt and precede the onset of chest pain; moreover, they are followed by an increase in left ventricular internal diameters. In conclusion M-mode echocardiography is a sensitive technique capable to detect transient myocardial ischemia in the course of spontaneous or induced angina with ST segment elevation or positivity of negative T wave. This approach could be helpful in the diagnostic evaluation of patients with atypical chest pain and/or aspecific ECG changes and it can be complementary to other non invasive techniques such dynamic ECG and nuclear cardiology techniques.
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PMID:[Diagnosis of transient acute myocardial ischemia in man by M-mode echocardiography (author's transl)]. 732 34

Coronary artery aneurysm was demonstrated in 7 patients, whose ages ranged from 38 to 66 years, by selective coronary angiography. Four patients had atypical chest pain probably not caused by cardiac ischemia, 1 patient had aortic stenosis and recurrent bouts of atrial fibrillation, and 2 were evaluated following myocardial infarction and found to have triple vessel atherosclerotic coronary disease. Mitral valve prolapse and varicosities of the coronary venous tree found in one individual suggest that mucoid degeneration which replaces the normal fibrous tissue resulting in weakness of vessel wall may be responsible for the formation of coronary artery aneurysm and varicosities of the coronary venous system. The unsuspected presentation and benign course of these patients are emphasized and the pertinent literature is reviewed.
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PMID:Coronary artery aneurysms. Report of seven cases and review of the pertinent literature. 737 59

Aim of the study was to verify the relationship between syndrome X and generalized microangiopathy. Three groups of patients were selected: Group A, 11 patients with typical syndrome X; Group B, 8 patients with atypical chest pain; Group C, 12 control normal subjects. Microvascular circulation was investigated with a laser Doppler Periflux PF3 at rest (15 min); during ischemia (3 min); during post-ischemic hyperemia on the plantar side of the big toe (where arterovenous anastomoses are particularly abundant) and on the dorsum of the foot (where these anastomoses are very scanty). During each recording we calculated: the mean flux value (FV); the mean concentration of moving blood cells (CMBC); the FV/CMBC ratio (which is related to the flow velocity); the mean percent increase of the three parameters during hyperemia. Patients with syndrome X as compared to the other subjects showed: 1) a significantly higher FV/CMBC ratio at rest and during hyperemia both on the plantar side of the big toe (respectively p = 0.01 and 0.015) and on the dorsum of the foot (respectively p = 0.011 and 0.006). These findings suggest a higher flow velocity in microvascular circulation; significantly lower percent increase of FV and CMBC during hyperemia in the plantar side of the big toe (respectively p = 0.04 and 0.014) but not on the dorsum. The increase of flow velocity at rest and low vasodilatatory reserve after ischemia in an area which is rich of arterovenous anastomoses in patients with syndrome X might be explained by the presence of a basal arterovenous hyperstomia.
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PMID:[Study of cutaneous microcirculation using the laser-Doppler method in syndrome X]. 803 98


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