tellurium and Coronary-Disease

Emergency room evaluations of patients presenting with chest pain continue to rise, and these evaluations which often include cardiac imaging, are an increasing area of resource utilization in the current health system. Myocardial perfusion imaging from the emergency department remains a vital component of the diagnosis or exclusion of coronary artery disease as the etiology of chest pain. Recent advances in camera technology, and changes to the imaging protocols have allowed MPI to become a more efficient way of providing this diagnostic information. Compared with conventional SPECT, new high-efficiency CZT cameras provide a 3-5 fold increase in photon sensitivity, 1.65-fold improvement in energy resolution and a 1.7-2.5-fold increase in spatial resolution. With stress-only imaging, rest images are eliminated if stress images are normal, as they provide no additional prognostic or diagnostic value and cancelling the rest images would shorten the length of the test which is of particular importance to the ED population. The rapid but accurate triage of patients in an ED CPU is essential to their care, and stress-only imaging and new CZT cameras allow for shorter test time, lower radiation doses and lower costs while demonstrating good clinical outcomes. These changes to nuclear stress testing can allow for faster throughput of patients through the emergency department while providing a safe and efficient evaluation of chest pain.

Topics: Cadmium; Chest Pain; Coronary Disease; Emergency Service, Hospital; Exercise Test; Humans; Myocardial Perfusion Imaging; Radiopharmaceuticals; Risk Assessment; Tellurium; Tomography, Emission-Computed, Single-Photon; Zinc

Myocardial perfusion imaging (MPI) is valuable for diagnosing coronary disease and assessing the risk of cardiac events. New technology based on semiconductors (Cadmium zinc telluride-CZT) enables reducing imaging time and improving image quality.. We retrospectively identified 57 patients who underwent MPI at Assuta using a CZT camera and invasive coronary angiography (ICA) within 60 days following nuclear testing without an intervening cardiac event, and without history of coronary disease. In addition, 25 patients with low pretest likelihood who did not undergo ICA were included in the study. All 82 patients underwent fast-acquisition, stress-first Tc-99m sestamibi MPI using very short imaging time (stress: 5:00 min., prone: 3:40 min. and rest: 2:00 min]. A low-dose stress injection (9-12 mCi, ≤ 3.5 mSv) and high rest-dose (25-32 mCi) with adjustment to patient weight were administered. Semi-quantitative visual analysis utilized a 17-segment model, 0-4 scale (0 = normal uptake, 4 = absent uptake). The summed stress score (SSS) representing stress perfusion abnormality was converted to a percentage of abnormal myocardium (SSS% = SSS/68*100). ICA served as a gold standard for the nuclear perfusion findings.. The mean age was 60.1 ± 11 years and most subjects were men (58, 70.7%). Compared to low-risk patients, patients who underwent ICAwere older, and had a higher frequency of hypertension, diabetes mellitus and dyslipidemia. A low-dose stress-only test with low radiation exposure ≤ 3.5 mSv) was frequent among low-risk patients (18/25-72%). ROC analysis for identification of angiographic coronary disease by SSS% demonstrated area under curve of 0.923, 95% confidence interval 0.859-0.988, p < 0.001. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were: 91.4%, 81.2%, 78.3%, 97.2% and 86.6%, respectively.. Fast, low-dose stress MPI using CZT technology enables semi-quantitative analysis with high diagnostic value for coronary disease.

Topics: Aged; Cadmium; Coronary Angiography; Coronary Disease; Female; Humans; Male; Middle Aged; Myocardial Perfusion Imaging; Predictive Value of Tests; Reproducibility of Results; Retrospective Studies; Sensitivity and Specificity; Technetium Tc 99m Sestamibi; Tellurium; Time Factors; Zinc

A continuous ventricular function monitor with a miniature cadmium telluride detector was evaluated and applied to patients with coronary bypass surgery (CABG). Ejection fraction (EF) at rest and change in EF from rest to exercise and postexercise (Y) measured with the device correlated with that of the gamma camera (X) (Y = 0.86x + 6.8(%), r = 0.87, n = 110, p less than 0.001, and Y = 0.96x + 0.4(%), r = 0.90, n = 37, p less than 0.001 respectively). Left ventricular function during and after supine ergometer exercise was monitored in 54 patients before and after CABG. The EF change from baseline to peak exercise improved from -5.9% +/- 8.9% before CABG to 7.2% +/- 7.9% after CABG (p less than 0.001). In all patients but two, a rapid EF increase just after exercise over baseline EF was observed. This EF "overshoot" during recovery increased from 11.5% +/- 6.5% to 16.4% +/- 6.0% (p less than 0.001) after CABG. The time from the cessation of exercise to EF overshoot decreased from 153 +/- 80 sec to 76 +/- 49 sec (p less than 0.001) after CABG. The continuous ventricular function monitor with a miniature cadmium telluride detector is able to measure EF reliably. Following successful aortocoronary bypass, EF response during exercise improved and the EF overshoot in the recovery phase became faster and higher.

Topics: Cadmium; Cadmium Compounds; Cardiology; Coronary Artery Bypass; Coronary Disease; Gated Blood-Pool Imaging; Hemodynamics; Humans; Monitoring, Physiologic; Tellurium; Ventricular Function, Left

Topics: Cadmium; Cadmium Compounds; Cardiology; Coronary Disease; Radionuclide Imaging; Tellurium; Ventricular Function, Left

Topics: Adult; Aged; Cadmium; Cadmium Compounds; Coronary Disease; Female; Heart; Humans; Hypertension; Male; Middle Aged; Monitoring, Physiologic; Physical Exertion; Radionuclide Ventriculography; Stroke Volume; Tellurium

The degree of exercise-induced cardiac dysfunction and its relation to the anaerobic threshold were evaluated in 23 patients with chronic heart disease. A symptom-limited exercise test was performed with a cycle ergometer with work rate increased by 1 W every 6 seconds. Left ventricular function, as reflected by ejection fraction, was continuously monitored with a computerized cadmium telluride detector after the intravenous injection of technetium-labeled red blood cells. The anaerobic threshold (mean, 727 +/- 166 ml/min) was determined by the noninvasive measurement of respiratory gas exchange. As work rate rose, the left ventricular ejection fraction increased but reached a peak value at the anaerobic threshold and then fell below resting levels. Ejection fraction at rest, anaerobic threshold, and peak exercise were 41.4 +/- 11.3%, 46.5 +/- 12.0%, and 37.2 +/- 11.0%, respectively. Stroke volume also increased from rest (54.6 +/- 17.0 ml/beat) to the point of the anaerobic threshold (65.0 +/- 21.2 ml/beat) and then decreased at peak exercise (52.4 +/- 18.7 ml/beat). The slope of the plot of cardiac output versus work rate decreased above the anaerobic threshold. The anaerobic threshold occurred at the work rate above which left ventricular function decreased during exercise. Accurate determination of the anaerobic threshold provides an objective, noninvasive measure of the oxygen uptake above which exercise-induced deterioration in left ventricular function occurs in patients with chronic heart disease.

Topics: Anaerobic Threshold; Cadmium; Cadmium Compounds; Coronary Disease; Dye Dilution Technique; Electrocardiography; Erythrocytes; Exercise Test; Female; Heart; Humans; Male; Middle Aged; Radionuclide Angiography; Stroke Volume; Technetium; Tellurium

Topics: Adult; Aged; Cadmium; Cadmium Compounds; Coronary Disease; Female; Heart; Heart Ventricles; Humans; Hypertension; Male; Middle Aged; Monitoring, Physiologic; Radionuclide Angiography; Tellurium

To determine the effects of tellurium-heteroatom position on myocardial fatty-acid kinetics, a series of tellurium Te 123m-labeled heptadecanoic-acid analogs (123mTe-THDA) were evaluated in dogs. The left-anterior descending coronary artery was partially occluded, and 123mTe-THDA labeled at either the 5, 6, 9, 10, 11, 12, or 13 position from the carboxyl group was administered intravenously. In 24 dogs, the 123mTe activity in the ischemic and normal zones was monitored continuously for 3 h using miniature radiation detectors. There were no significant differences between the ischemic- and normal-wall 123mTe clearance rates for any of the compounds. There was minimal fractional 3-h myocardial clearance for the 123mTe-THDA labeled at the 5, 6, and 9 position (range of means, 0.02-0.05). There was significant clearance of 123mTe-THDA labeled at the 11, 12, and 13 position (range of means, 0.37-0.44). The myocardial clearance of the 123mTe-THDA labeled at the 10 position was intermediate between the two extremes. Thus, as the 123mTe heteroatom is placed further from the carboxyl portion of the molecule, there is a progressive increase in the myocardial clearance. Selection of the heteroatom position should depend on whether initial fatty-acid distribution or subsequent clearance rates are being studied.

Topics: Animals; Coronary Disease; Dogs; Fatty Acids; Heart; Hemodynamics; Isotopes; Kinetics; Myocardium; Radionuclide Imaging; Structure-Activity Relationship; Tellurium

The myocardial uptake of 15-(p-iodophenyl)-6- tellurapentadecanoic acid ( TPDA ) was studied in dogs during coronary occlusion and after reperfusion. In eight dogs with a 3 hour occlusion (Group A) with (n = 5) and without (n = 3) 30 minutes of reperfusion, iodine-125 TPDA uptake correlated well with microsphere myocardial blood flow over a wide range of flow levels (n = 111, r = 0.94). In six dogs with a 20 minute occlusion of the left anterior descending coronary artery and 1 hour of reperfusion (Group B), iodine-125 TPDA uptake correlated equally well with myocardial blood flow (n = 37, r = 0.90). There was no difference between the slopes of regression lines for Groups A and B, indicating no release from the myocardium of radioiodinated TPDA . Dual radiolabeling of TPDA was employed in five Group A animals by intravenous injection of iodine-125 TPDA during coronary occlusion and iodine-131 TPDA after reperfusion. In 63 myocardial samples, microsphere reperfusion flow and iodine-131 TPDA uptake were closely correlated (r = 0.91). As with monovalent cations, at myocardial flows higher than control flows, iodine-131 TPDA uptake was flow-limited. It is concluded that: 1) radioiodinated TPDA accurately reveals severely ischemic areas of myocardium without myocardial release of the radionuclide in coronary occlusions lasting 20 to 180 minutes and followed by reperfusion, and 2) double radiolabeled TPDA allows assessment of both occlusion and reperfusion flows. This compound may find an application in the measurement of infarct size and the evaluation of interventional therapies in acute myocardial infarction.

Topics: Animals; Blood Pressure; Coronary Circulation; Coronary Disease; Dogs; Female; Heart; Heart Rate; Iodine Radioisotopes; Iodobenzenes; Male; Microspheres; Myocardium; Radionuclide Imaging; Tellurium

Topics: Animals; Coronary Disease; Disease Models, Animal; Dogs; Fatty Acids; Heart; Isotopes; Microspheres; Radioisotopes; Radionuclide Imaging; Scandium; Tellurium; Tin