discussion the reason is that we assess the relative and not absolute differences of the tracer uptake in this imaging modality. there may be other findings on mpi images which could help us overcome this pitfall, including detecting wall motion abnormalities, lung uptake of the tracer, or transient ischemic dilation. another important issue is the ecg changes during exercise stress testing, wh...

Objectives. We sought to assess the relation between glucose metabolism, myocardial perfusion and cardiac work after orthotopic heart transplantation. Background. The metabolic profile of the transplanted cardiac muscle is affected by the lack of sympathetic innervation, impaired inotropic function, chronic vasculopathy, allograft rejection and immunosuppressive therapy. In relation to myocardi...

Heart failure is the leading cause of mortality in patients with transfusional iron (Fe) overload in which myocardial iron uptake ensues via a transferrin-independent process. We examined the ability of L-type Ca channel modifiers to alter Fe uptake by isolated rat hearts and ventricular myocytes. Perfusion of rat hearts with 100 nmol/L Fe and 5 mmol/L ascorbate resulted in specific Fe uptake o...

Heart failure is the leading cause of mortality in patients with transfusional iron (Fe) overload in which myocardial iron uptake ensues via a transferrin-independent process. We examined the ability of L-type Ca2+ channel modifiers to alter Fe2+ uptake by isolated rat hearts and ventricular myocytes. Perfusion of rat hearts with 100 nmol/L 59Fe2+ and 5 mmol/L ascorbate resulted in specific 59F...

BACKGROUND There is growing awareness of secondary insulin resistance and alterations in myocardial glucose utilization in congestive heart failure. Whether therapies that directly target these changes would be beneficial is unclear. We previously demonstrated that acute blockade of the insulin responsive facilitative glucose transporter GLUT4 precipitates acute decompensated heart failure in m...

In previous in vivo studies with mice, rats, cats and monkeys, we have demonstrated that [7-methyl-11C]-(E)-8-(3,4,5-trimethoxystyryl)- 1,3,7-trimethylxanthine ([11C]TMSX) is a potential radioligand for mapping adenosine A2A receptors of the brain by positron emission tomography (PET). In the present study, we studied the potential of [11C]TMSX for myocardial imaging. Uptake of radioactivity by...

The predictive value of the myocardial scintigraphy with 99mTc-pyrophosphate was studied in 100 patients admitted to the coronary care unit with suspected acute myocardial infarction. None of the 21 patients with normal scintigrams had acute myocardial infraction by other criteria. Fifty-five percent of patients with diffuse uptake (pattern B), 73% of patients with focal uptake (pattern C) and ...

The myocardial uptake of In-111 antimyosin Fab and Tc-99m pyrophosphate was studied in dogs undergoing coronary artery occlusion for 90 minutes followed by reperfusion. The regional myocardial blood flow was determined by injecting Sc-46 labeled microsphere and was related to the relative concentrations of In-111 antimyosin and Tc-99m pyrophosphate. There was an inverse linear correlation betwe...

Dilated cardiomyopathy (DCM) is characterized by a metabolic shift from fat to carbohydrates and failure to increase myocardial glucose uptake in response to workload increments. We verified whether this pattern is influenced by an abnormal glucose tolerance (AGT). In 10 patients with DCM, 5 with normal glucose tolerance (DCM-NGT) and 5 with AGT (DCM-AGT), and 5 non-DCM subjects with AGT (N-AGT...

Insulin resistance is common in patients with angina pectoris, a positive exercise electrocardiogram, and normal coronary angiograms (syndrome X). It is still not known whether insulin resistance affects the cardiac muscle itself and, if so, whether insulin resistance involves myocardial hemodynamics and energy metabolism. We investigated hemodynamics as well as metabolite exchanges across the ...