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Vasken Dilsizian - One of the best experts on this subject based on the ideXlab platform.
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myocardial viability in patients with chronic coronary artery disease comparison of 99mtc sestamibi with Thallium reinjection and 18f fluorodeoxyglucose
Circulation, 1994Co-Authors: Vasken Dilsizian, James A Arrighi, Jean G Diodati, Arshed A Quyyumi, Karim Alavi, Stephen L Bacharach, Jose A Marinneto, P T Katsiyiannis, Robert O BonowAbstract:BACKGROUND99mTc-sestamibi and Thallium imaging have similar accuracy when used for diagnostic purposes, but whether sestamibi provides accurate information regarding myocardial viability in patients with chronic coronary artery disease has not been established. Since there is minimal redistribution of sestamibi over time, it may overestimate nonviable myocardium in patients with left ventricular dysfunction, in whom blood flow may be reduced at rest.METHODS AND RESULTSWe studied 54 patients with chronic coronary artery disease with a mean ejection fraction of 34 +/- 14%. Patients underwent stress/redistribution/reinjection Thallium tomography and, within a mean of 5 days, same-day rest/stress sestamibi imaging using the same exercise protocol and with patients achieving the same exercise duration. Of the 111 reversible Thallium defects on either the redistribution or reinjection study, 40 (36%) were determined to be irreversible on the rest/stress sestamibi study, whereas only 3 of 63 irreversible thalliu...
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Thallium 201 for assessment of myocardial viability
Seminars in nuclear medicine, 1991Co-Authors: Robert O Bonow, Vasken DilsizianAbstract:Left ventricular (LV) performance is reduced in a large subset of patients with chronic coronary artery disease (CAD) and LV dysfunction on the basis of regionally ischemic or hibernating myocardium rather than irreversibly infarcted tissue. The detection of dysfunctional but viable myocardium is clinically relevant since regional and global LV function in such patients will improve after revascularization procedures; however, the identification of patients with such potentially reversible LV dysfunction is difficult. Although Thallium 201 imaging may be of value in detecting viable myocardium if regions with perfusion defects during exercise demonstrate redistribution of Thallium on a 3- to 4-hour resting image, Thallium defects often appear persistently "fixed" within regions of severely ischemic or hibernating myocardium. It has been shown that up to 50% of regions with apparently irreversible Thallium defects will improve in function after revascularization. Thus, standard exercise-redistribution Thallium scintigraphy may not differentiate LV dysfunction arising from infarcted versus hibernating myocardium. The precision with which Thallium imaging identifies viable myocardium can be improved greatly by additional studies once 4-hour redistribution imaging demonstrates an irreversible Thallium defect. These additional studies include late (24-hour) redistribution imaging, repeat imaging after Thallium reinjection, or a combination of Thallium reinjection followed by late imaging. Several recent studies suggest that Thallium reinjection techniques, by demonstrating Thallium uptake in dysfunctional regions with apparently irreversible defects, predict improvement after revascularization with similar predictive accuracy as that achieved using metabolic imaging with positron emission tomography (PET). Studies directly comparing such Thallium methods and PET, which thus far involve only small numbers of patients, suggest that the assessment of regional metabolic activity using PET and the assessment of regional Thallium activity using single photon emission computed tomography provide concordant results. These findings, if confirmed by larger ongoing studies, suggest that Thallium reinjection imaging is a convenient, clinically accurate, and relatively inexpensive method with which to identify viable myocardium in patients with chronic CAD and LV dysfunction.
Robert O Bonow - One of the best experts on this subject based on the ideXlab platform.
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myocardial viability in patients with chronic coronary artery disease comparison of 99mtc sestamibi with Thallium reinjection and 18f fluorodeoxyglucose
Circulation, 1994Co-Authors: Vasken Dilsizian, James A Arrighi, Jean G Diodati, Arshed A Quyyumi, Karim Alavi, Stephen L Bacharach, Jose A Marinneto, P T Katsiyiannis, Robert O BonowAbstract:BACKGROUND99mTc-sestamibi and Thallium imaging have similar accuracy when used for diagnostic purposes, but whether sestamibi provides accurate information regarding myocardial viability in patients with chronic coronary artery disease has not been established. Since there is minimal redistribution of sestamibi over time, it may overestimate nonviable myocardium in patients with left ventricular dysfunction, in whom blood flow may be reduced at rest.METHODS AND RESULTSWe studied 54 patients with chronic coronary artery disease with a mean ejection fraction of 34 +/- 14%. Patients underwent stress/redistribution/reinjection Thallium tomography and, within a mean of 5 days, same-day rest/stress sestamibi imaging using the same exercise protocol and with patients achieving the same exercise duration. Of the 111 reversible Thallium defects on either the redistribution or reinjection study, 40 (36%) were determined to be irreversible on the rest/stress sestamibi study, whereas only 3 of 63 irreversible thalliu...
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Thallium 201 for assessment of myocardial viability
Seminars in nuclear medicine, 1991Co-Authors: Robert O Bonow, Vasken DilsizianAbstract:Left ventricular (LV) performance is reduced in a large subset of patients with chronic coronary artery disease (CAD) and LV dysfunction on the basis of regionally ischemic or hibernating myocardium rather than irreversibly infarcted tissue. The detection of dysfunctional but viable myocardium is clinically relevant since regional and global LV function in such patients will improve after revascularization procedures; however, the identification of patients with such potentially reversible LV dysfunction is difficult. Although Thallium 201 imaging may be of value in detecting viable myocardium if regions with perfusion defects during exercise demonstrate redistribution of Thallium on a 3- to 4-hour resting image, Thallium defects often appear persistently "fixed" within regions of severely ischemic or hibernating myocardium. It has been shown that up to 50% of regions with apparently irreversible Thallium defects will improve in function after revascularization. Thus, standard exercise-redistribution Thallium scintigraphy may not differentiate LV dysfunction arising from infarcted versus hibernating myocardium. The precision with which Thallium imaging identifies viable myocardium can be improved greatly by additional studies once 4-hour redistribution imaging demonstrates an irreversible Thallium defect. These additional studies include late (24-hour) redistribution imaging, repeat imaging after Thallium reinjection, or a combination of Thallium reinjection followed by late imaging. Several recent studies suggest that Thallium reinjection techniques, by demonstrating Thallium uptake in dysfunctional regions with apparently irreversible defects, predict improvement after revascularization with similar predictive accuracy as that achieved using metabolic imaging with positron emission tomography (PET). Studies directly comparing such Thallium methods and PET, which thus far involve only small numbers of patients, suggest that the assessment of regional metabolic activity using PET and the assessment of regional Thallium activity using single photon emission computed tomography provide concordant results. These findings, if confirmed by larger ongoing studies, suggest that Thallium reinjection imaging is a convenient, clinically accurate, and relatively inexpensive method with which to identify viable myocardium in patients with chronic CAD and LV dysfunction.
J Bax, Md - One of the best experts on this subject based on the ideXlab platform.
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Prediction of Recovery of Myocardial Dysfunction After Revascularization Comparison of Fluorine-18 Fluorodeoxyglucose/Thallium-201 SPECT, Thallium-201 Stress–Reinjection SPECT and Dobutamine Echocardiography
Journal of the American College of Cardiology, 1996Co-Authors: J Bax, MdAbstract:textabstractObjectives. We compared: three techniques to predict functional recovery after revascularization. Background. Recently, fluorine-18 (F-18) fluorodeoxyglucose in combination with single-photon emission computed tomography (SPECT) has been proposed to identify viable myocardium. Thallium-201 reinjection and 'low' dose dobutamine echocardiography are used routinely for this purpose. Methods. Seventeen patients (mean [±SD] left ventricular ejection fraction 36 ± 11%) were studied. Regional and global ventricular function were evaluated before and 3 months after revascularization by echocardiography and radionuclide ventriculography, respectively. Myocardial F-18 fluorodeoxyglucose uptake (during hyperinsulinemic glucose clamping) was compared with rest perfusion assessed with early Thallium-201 SPECT. Oh a separate day, low dose dobutamine echocardiography and post-stress Thallium-201 reinjection SPECT were simultaneously performed. Results. The sensitivities for F18 fluorodeoxyglucose/Thallium-201, Thallium-301 reinjection and low dose dobutamine echocardiography to assess recovery were 89%, 93% and 85%, respectively; specificities were 77%, 43% and 63%, respectively. Stepwise logistic regression indicated that F-18 fluorodeoxyglucose/ Thallium-201 was the best predictor. In hypokinetic segments, the combination of F-18 fluorodeoxyglucose/Thallium-201 and low dose dobutamine echocardiography was the best predictor. Global function improved (left ventricular ejection fraction increased > 5%) in 6 patients and remained unchanged in 11. All three techniques correctly identified five of six patients with improvement. Fluorine-18 fluorodeoxyglucose/Thallium-201 identified all patients without improvement; low dose dobutamine echocardiography identified 9 of 11 without improvement; and Thallium-201 reinjection identified 6 of 11 patients without improvement, Conclusions. Fluorine-18 fluorodeoxyglucose/Thallium-201 SPECT was superior to the other techniques in assessing functional recovery. Integration of metabolic and functional data is necessary, particularly in hypokinesia, for optimal prediction of improvement of regional function
Luis Sánchez-harguindey - One of the best experts on this subject based on the ideXlab platform.
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Assessment of cardiac viability by Thallium 201 redistribution and dobutamine echocardiography
American Heart Journal, 2002Co-Authors: José Zamorano, Juan Vicente Delgado, Teresa Sotelo, Enrique Meroño, Rufilanchas Jj, Miguel Sol-sanchez, Carlos Almeria, Raul Moreno, Cristina Fernandez, Luis Sánchez-harguindeyAbstract:Objective Dobutamine echocardiography and thalium 201 are useful in the assessment of myocardial viability, but both techniques frequently yield conflicting results. The objective of this study was to determine the minimum mass of viable myocardium that each test could detect and compare the agreement of dobutamine echocardiography and Thallium 201 to detect viability. Methods Dobutamine echocardiography and Thallium 201 were performed in 10 patients scheduled for cardiac transplantation. In each patient, 15 segments were studied. After transplantation these segments were analyzed by the pathologist measuring by a computer system the total area of each segment, the necrotic + fatty mass, and area (%) of viable myocytes per segment. The percentage of viable tissue was estimated ([Total mass – (Necrotic + Fatty tissue)]/Total mass × 100) on each segment, which was compared with the result (viable or not viable) obtained by echocardiography or Thallium 201. Results Dobutamine echocardiography defined 90 segments (60%) as viable versus 117 (78%) in Thallium (κ 0.49, 95% CI 0.36-0.63). The minimum percent of viable tissue per segment defined as viable by Thallium was 43% versus 49% by echocardiography. With use of Thallium, the highest accuracy of the test to detect viability was when the percent of necrotic tissue of the segment analyzed was 40% (positive and negative likelihood ratio 2.2 and 3.6, respectively). By use of echocardiography, the highest accuracy of the test was observed when the percent of necrotic tissue of the segment analyzed was 31% (positive and negative likelihood ratio 5.5 and 7.7, respectively). Conclusion The discrepant results of dobutamine echocardiography and Thallium 201 are due to differences in the minimum mass of live myocytes required by each technique to detect viability. (Am Heart J 2002;143:157-62.)
Mario S Verani - One of the best experts on this subject based on the ideXlab platform.
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equivalence between adenosine and exercise Thallium 201 myocardial tomography a multicentre prospective crossover trial
Journal of the American College of Cardiology, 1992Co-Authors: Shigeyuki Nishimura, John J Mahmarian, Terri M Boyce, Mario S VeraniAbstract:Abstract Objectives. The study was designed to compare pharmacologic and exercise stress during thallum-201 single-photon tomography in a multkenter prospective crossover trial. Background. Both exercise and adenosine myocardial perfusion imaging have high sensitivity and specificity for detection of coronary artery disease. However, few data are available comparing these two stress tests in the same patients. Methods. The study group consisted of 175 subjects: 55 healthy volunteers and 120 patients with suspected coronary artery disease. All subjects underwent two thalium tomograpltic tests performed 30 days apart, one during intravenous administration of adenosine (140 μg/kg per min for 6 min) and one during exercise stress. All images were computer quantified and interpreted without knowledge of the stress test performed. Interpretation agreement was assessed by kappa and Z statistics. Results. Agreement on the presence of normal or abnormal tomograms by adenosine and exercise scintigraphy was 82.8% by visual analysis with kappa and Z statistics of 0.65 (p Conclusions. Adenosine Thallium-201 scintigraphy provides diagnostic information similar to that of exercise scintigraphy, although values for defect sizes are greater with adenosine.