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Research Studies
Cardiac
| Detection and Assessment of Free Fatty Acid Utilization by Cardiac Muscle in Patients with Lipoprotein Lipase Deficiency using PET (5214) |
We plan to study myocardial blood flow, oxygenation and free fatty acid, and glucose uptake by the cardiac muscle using Positron Emission Tomography (PET).
Fatty Acids (FA) are an important fuel source for heart and skeletal muscle, providing over 70% of the energy needs for cardiac function. FA is delivered to cardiac myocytes in three ways:
1) FA are derived from the hydrolysis of triglyceride (TG) stored in adipose tissue via hormone-sensitive lipase and circulate in the blood with albumin;
2) FA are produced from intracellular hydrolysis of TG in the core of internalized lipoproteins;
3) FA are also generated in the local capillary bed by lipoprotein lipase (LPL)-mediated hydrolysis of TG in circulating chylomicrons and very low-density lipoproteins (VLDL).
The purpose of this investigation is to determine how the hearts of patients with LPL deficiency obtain fatty acids or glucose as a source of energy. In addition, the myocardial blood flow and oxygenation of the heart of individuals with LPL deficiency will be evaluated.
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| Study of Myocardial Perfusion and Coronary Anatomy Imaging Roles in Coronary Artery Disease (SPARC) () |
SPARC, including its Pilot CT angiographic study, is a prospective, open-label, multicenter, sequentially sampled, observational registry to define the clinical value of stress perfusion (stress SPECT, stress PET), noninvasive angiography (CTA) and combined perfusion-anatomy (PET/CT) studies in patients with known or suspected CAD with respect to post-test resource utilization and prediction of cardiac death and non-fatal myocardial infarction.
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| Novel Radionuclide Imaging Approaches for the Early Diagnosis of Pulmonary Arterial Hypertension and the Detection of its Later Sequelae () |
Pulmonary artery hypertension as a familial disease, associated with scleroderma, or congenital heart disease, it is an uncommon disorder but highly lethal. Frequently the diagnosis is not made until the patient develops symptoms associated with hemodynamic compromise that is a late sequela of the disease. The cause of death in these patients is most likely due to right ventricle (RV) failure.
It would be clinically important to identify these patients earlier in the course of the disease. This study is designed to study subjects’ right ventricle functions (blood flow, substrate metabolism, etc.) with a non-invasive imaging modality, Positron Emission Tomography (PET). The data obtained from this study may prove valuable in early diagnosis, determinant of prognosis, selection of patients for therapy, and for evaluating new drugs.
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| Clinical Assessment of Myocardial Viability in Patients with Coronary Artery Disease () |
The PET image is for clinical Assessment of Myocardial Viability in Patients with Coronary Artery Disease.
The purpose for this protocol is to seek patients' permissions to put their medical information into our data base for future medical research. In other words, we are after research consent for the data collection of medical research.
This protocol is NOT for describing the clinical cardiac PET viability study itself.
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| Effect of Diabetes Control on Cardiac Autonomic Nerves () |
Approximately 16 million Americans have diabetes mellitus and about 1/3 of these patients demonstrate abnormal autonomic function on clinical testing. Autonomic dysfunction has been associated with increased morbidity and mortality. Because of our previous inability to measure damage in sympathetic neurons, little is known about the actual pathophysiology of cardiac sympathetic denervation in diabetic patients. PET imaging now allows us to quantitatively measure and study cardiac nerve function.
The objective of this study is to quantitatively assess cardiac carbon (C-11) hydroxyephedrine uptake as a marker for the imaging of postsynaptic sympathetic receptor occupancy (Bmax), and to correlate the regional Bmax with conventional markers of sympathetic and parasympathetic dysfunction in patients with autonomic neuropathy. We will also determine whether observed scintigraphic findings are due to irreversible or potentially reversible functional disturbances of sympathetic neurons.
We will study 15 diabetic patients and 7 normal control subjects. Diabetic patients will twice undergo both the standard 3-test American Diabetic Association (ADA) battery for the diagnosis of cardiac autonomic neuropathy and quantitative C-11 hydroxyephedrine imaging as evaluated by PET: first shortly after initial diagnosis and then again after 3-6 months of glycemic control. We believe there is a correlation between autonomic dysfunction, as assessed by ADA testing criteria, and regional variation in Bmax. We also believe that the degree of blood glucose control in diabetics is a determinant of autonomic nervous system function and that improvement in glycemic control will correlate with improved autonomic function and improvement in Bmax.
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Patients
