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  • 1
    ISSN: 1619-7089
    Schlagwort(e): Thallium 201 myocardial scintigraphy ; Thallium 201 washout ; Exercise test ; Coronary artery disease
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Quantitative analysis of myocardial exercise scintigraphy has been previously reported to be superior to visual image interpretation for detection of the presence and extent of coronary artery disease. Computer analysis of perfusion defects and washout rate of thallium 201 was performed on scintigrams from a group of 131 consecutive patients (prospective group), using criteria defined from a previous group of 72 patients (initial group), and compared with visual interpretation of scintigrams for detection and evaluation of coronary artery disease. The sensitivity of the quantitative technique with regard to overall detection of coronary artery disease was not significantly different from the visual method (69% and 74%, respectively), whereas the specificity was higher (86% and 68%). Quantitative analysis did not increase the sensitivity of thallium imaging over the visual method in the left anterior descending artery (46% vs 65%) and the right coronary artery (51% vs 72%) but did increase sensitivity in the left circumflex artery (75% vs 47%). Whereas in the initial group quantitative analysis resulted in a better identification of multivessel disease (sensitivity 81 % vs 57%), in the prospective group sensitivity decreased (54% vs 67%) without significant loss of specificity. The initial group had a 40% incidence of three-vessel disease and the prospective group, 22% (P 〈 0.05). One-vessel disease was higher in the prospective group (32% vs 11%,P 〈 0.05). Thus, assessing the quantitative technique in a larger prospective patient population, there was no improvement of detection of the presence and extent of coronary artery disease when compared with visual interpretation.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 2
    ISSN: 1619-7089
    Schlagwort(e): Thallium-201 scintigraphy ; Coronary artery disease ; β-Blocking agents ; Prognosis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The prognostic value of a normal exercise thallium-201 scintigram was determined in 211 patients with a normal exercise and resting scintigram. Endpoints were sudden cardiac death, non-fatal acute myocardial infarction and coronary artery bypass grafting or percutaneous transluminal coronary angioplasty. Forty patients (19%) had a history of a previous myocardial infarction and 40 (19%) were known to have had a previous percutaneous transluminal coronary angioplasty or coronary artery bypass grafting. Sixty-four patients (31%) were on treatment with β-blocking agents. After a mean follow-up period of 23.5 months, 22 patients had had a cardiac event (1 cardiac death, 6 myocardial infarction, 15 revascularization). For the total group, the 1-year event rate for cardiac death, myocardial infarction, percutaneous transluminal coronary angioplasty or coronary artery bypass grafting was 7.0%. For cardiac death or myocardial infarction alone the event rate was 2.8%. The only parameter independently predictive for cardiac events was the regular use of β-blocking agents. The high event rate in patients on β-blocking treatment is partly due to the fact that these patients were more symptomatic for coronary artery disease. The sustained β-adrenergic blockade in this patient group, even in patients advised to stop medication, was suspected to interfere with the results of 201Tl scintigraphy. Therefore, more attention should be paid to patient instruction regarding the discontinuation of medication before the test.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 3
    ISSN: 1619-7089
    Schlagwort(e): Myocardial perfusion ; Cardiac wall motion ; Thallium-201 scintigraphy ; Technetium-99m sestamibi scintigraphy ; Coronary artery disease
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Measurements of myocardial perfusion and ventricular function are expected to provide additional information in the detection of coronary artery disease (CAD). The purpose of this study was threefold: (1) to determine to what extent technetium-99m sestamibi wall motion yields different information compared with99mTc-sestamibi and thallium-201 perfusion; (2) to test which information unique to either study is of value in diagnosing CAD; and (3) to assess the combination of variables with the highest diagnostic accuracy. Perfusion and wall motion scores (at rest and during exercise) obtained from visual and quantitative planar201T1 and99mTc-sestamibi scintigraphy of 60 patients with suspected CAD were compared with the angiographic results by means of a polytomous logistic regression model and the diagnostic values were compared with one another. All univariate variables were significantly related to the probability of CAD and its extent. Comparative studies revealed a large degree of correlation between201T1 stress and redistribution variables. The rest99mTc-sestamibi and wall motion studies contained partially different information. Stepwise logistic regression analysis showed the strongest diagnostic power for the combination of201Tl visual analysis of the stress images with quantitative redistribution images (sensitivity 93%, specificity 71%). The diagnostic power was similar for all combinations of visual and quantitative analyses of the exercise and redistribution images. The strongest diagnostic power of the99mTc-sestamibi variables was the score of the diastolic stress image (sensitivity 91%, specificity 79%). Comparable sensitivity and specificity estimates were found when both optimal models were compared. Wall motion studies did not have additional diagnostic power. Although99mTc-sestamibi wall motion studies, both at rest and during exercise, provide information in addition to the99mTc-sestamibi or201Tl myocardial perfusion variables, the information does not enhance the diagnostic power with regard to the prediction of CAD.
    Materialart: Digitale Medien
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  • 4
    ISSN: 1573-7241
    Schlagwort(e): nisoldipine ; acute myocardial infarction ; myocardial stunning ; left ventricular function ; radionuclide angiography
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Nisoldipine is a calcium antagonist with potent coronary vasodilating effects in patients with chronic stable angina pectoris. In an initial study we showed that intravenous nisoldipine, given 24–72 hours after uncomplicated myocardial infarction, was a safe and feasible intervention that had beneficial effects on global and regional myocardial function. We subsequently studied the acute effects of nisoldipine in six patients within 24 hours (mean 14±4 hours) after the onset of myocardial infarction. Nisoldipine was administered as a 4.5 µg/kg intravenous bolus over 3 minutes, followed by intravenous infusion of 0.2 µg/kg over 60 minutes. Radionuclide angiography, cardiac output, and intraarterial blood pressure measurements were performed before and during nisoldipine. Left ventricular ejection fraction increased from 48.3±10.3% to 55.3±11.8% (p=0.034) during nisoldipine infusion. Regional wall motion score changed during nisoldipine infusion from 3.3±2.5 to 1.8±2.6 (p=0.027). Cardiac output increased from 5.5±1.0 to 7.3±1.3 1/min (p=0.0001). I eart rate increased from 78±12 to 88±11 min−1 (p=0.004). Mean arterial blood pressure decreased from 92±20 to 79±13 mmI g (p=0.038). The rate-pressure product did not change significantly during nisoldipine infusion. It is concluded that nisoldipine improves global and regional left ventricular function in patients with acute myocardial infarction within the first 24 hours.
    Materialart: Digitale Medien
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  • 5
    ISSN: 1573-7241
    Schlagwort(e): nisoldipine ; acute myocardial infarction ; left ventricular function ; radionuclide angiography ; echocar-diography
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The acute effects on left ventricular function of nisoldipine were studied in six patients 56±12 hours (range 44 to 72 hours) after the onset of uncomplicated acute myocardial infarction. Nisoldipine was administered as a 4.5 μg/kg intravenous bolus over 3 minutes followed by an infusion of 0.2 μg/kg during 60 minutes. Radionuclide angiography and two-dimensional echocardiography were performed before and during infusien with nisoldipine. The left ventricular ejection fraction increased significantly from 38%±10% to 49%±10% (P=0.028) during nisoldipine infusion. Regional wall motion index was determined both by radionuclide and by two-dimensional echocardiography and showed a significant change during nisoldipine infusion from 1.9±0.3 to 1.5±0.3 (p=0.028, radionuclide angiography) and from 0.7±0.2 to 0.3±0.2 (p=0.043, two dimensional echocardiography). Heart rate increased significantly from 78±12 min-1 to 92±13 min-1 (p=0.028), but mean double product did not change significantly during nisoldipine infusion. It is concluded that nisoldipine significantly improves global and regional left ventricular function in patients shortly after acute myocardial infarction. This beneficial effect may, however, be partially offset by an increase in heart rate. Since mean double product did not change, it is suggested that nisoldipine may improve coronary blood flow in patients with acute myocardial infarction.
    Materialart: Digitale Medien
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  • 6
    ISSN: 1573-0743
    Schlagwort(e): Magnetic Resonance Imaging ; acute myocardial infarction ; Gadolinium-DPTA ; contrast agents
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary To assess the value of the paramagnetic contrast agent Gadolinium (Gd)-DTPA in Magnetic Resonance Imaging (MRI) of acute myocardial infarction (AMI), we studied 20 patients with a first AMI by ECG-gated MRI before and after intravenous administration of 0.15mmol/kg Gd-DTPA. The MRI studies were performed after a mean of 98 hours (range 15–241) after the acute onset of AMI. Spin-echo measurements (TE 30 msec) were made using a Philips Gyroscan (0.5 Tesla). After performing the baseline MRI scans, the MRI procedure was repeated every 10 minutes for up to 40 minutes following injection of Gd-DTPA. In 18 (90%) patients contrast enhancement in the infarcted myocardial areas was observed after Gd-DTPA. In these patients intensity versus region curves, derived from 9 to 11 adjacent myocardial regions of interest, showed increased signal intensities in the infarcted areas after administration of Gd-DTPA. The precontrast signal intensity ratio between infarcted and normal myocardium was 1.14±0.15 (mean±SD); the postcontrast ratios at 10 minutes were 1.41±0.21 (P 〈0.05), at 20 minutes 1.61±0.19 (P 〈0.01), at 30 minutes 1.43±0.20 (P 〈 0.05), and at 40 minutes 1.33±0.20 (P=NS). It is concluded that MRI using the contrast agent Gd-DTPA significantly improves the visualization and detection of infarcted myocardial areas in patients with AMI and that optimal contrast enhancement is obtained 20 minutes after administration of Gd-DTPA.
    Materialart: Digitale Medien
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