View clinical trials related to Cardiovascular Disease.
Filter by:The purpose of this study is to examine the impact of aerobic fitness on the ability of able and disabled older adults to perform daily functional activities. Subjects are tested in their oxygen use patterns as they perform a series of functional tasks (such as walking on stairs) and following a 24-week training program focused on improving the ability to perform daily tasks likely requiring aerobic fitness (such as walking on stairs).
A series of studies in patients with major depression have consistently demonstrated a doubling of the mortality rate at any age, independent of suicide. In addition, the relative risk for clinically significant coronary artery disease in patients with major depression is also 2 or more in studies that independently controlled for risk factors such as smoking, hypertension, etc. The principal long-term goals of the CNE include the determination of the mechanisms that underlie enhanced susceptibility to premature ischemic heart disease in patients with major depression, documenting the age at which demonstrable pathophysiologic or predictive changes begin to occur, and charting their rate of progression. Our long-term goal is to use our understanding of underlying mechanisms to enhance our capacity to predict who with major depression is most likely to develop premature ischemic heart disease, to determine what the mechanisms underlying this susceptibility are, and to develop improved means for treatment and prevention. Depressed patients are known to manifest a variety of neuroendocrine changes that predispose to coronary artery disease including hypercortisolism, decreased secretion of growth hormone and a deficiency of sex steroids. A final common denominator of these neuroendocrine abnormalities is insulin resistance. Insulin resistance promotes several changes that would favor hypertension and increased coronary artery disease including increased sodium retention, increased activity of the sympathetic nervous system, proliferation of vascular smooth muscle and deposition of highly metabolically active visceral fat. The latter induces additional risk factors for coronary disease, including dyslipidemia, hypercoagulation, and enhanced inflammation. It is a matter of public health importance to document the frequency and severity of insulin resistance in patients with major depression compared to a closely matched group of healthy controls. To accurately quantify insulin resistance in each patient and control, we will apply the hyperinsulinemic euglycemic glucose clamp procedure. This is the gold standard method for measuring the insulin sensitivity since it reflects the direct human body glucose metabolic response to a known insulin infusion. Moreover, it is essential to use this technique in patients with major depression as data indicate that other alternative procedures give unreliable results in the context of hypercortisolism.
Magnetic resonance imaging (MRI) and spectroscopy are diagnostic tools that create high quality images of the human body without the use of X-ray (radiation). MRI uses different levels of magnetic fields to create images of the body and organs. Occasionally, researchers will give patients undergoing a MRI an injection of a contrast substance. The contrast substance works by brightening areas of the magnetic resonance image. In this study researchers plan to use magnetic resonance imaging with contrast substances and exercise on normal volunteers in order to evaluate different aspects of its performance. Information gathered from this study may be used to develop more specific research studies involving MRI....
The renin angiotensin system is a complex process involving hormones and enzymes that regulate blood volume and blood pressure. The hormone angiotensin II is responsible for making blood vessels narrow or constrict. Angiotensin II is found in the blood and can attach to special sites called receptors on blood vessel walls. These receptors are programmed to accept angiotensin II and cause a constriction of the blood vessel. This function is found in the genetic information of each individual person. Occasionally patients have changes in their genes related to angiotensin II receptors. These changes may result in the receptors acting differently to angiotensin II, which may affect the function of blood vessels. This study is designed to improve researchers understanding of the physiological effects on blood vessels associated with mutations of the genes responsible for angiotensin II receptor function.
Magnetic resonance imaging (MRI) is a diagnostic tool that creates high quality images of the human body without the use of X-ray (radiation). MRI uses different levels of magnetic fields to create images of the body and organs. Occasionally, researchers will give patients undergoing a MRI an injection of a substance called gadolinium. Gadolinium works by brightening areas of the magnetic resonance image, thereby improving the contrast. In this study researchers will use magnetic resonance imaging and contrast substances, like gadolinium, on normal volunteers in order to evaluate different aspects of its performance. Information gathered from this study may be used to develop more specific research studies involving MRI.
An important mission of the National Institutes of Health (NIH) is to develop and carry out research studies designed to improve understanding of disease processes and treatments. Clinical research continues to become more focused on specific diseases and the signs and symptoms of diseases in specific groups of people and patients. This study is designed to permit inpatient evaluation and care of patients with heart disease who do not qualify to participate in research studies being conducted by the Cardiology Branch of the National Heart, Lung, and Blood Institute (NHLBI). These patients are valuable to the Cardiology Branch of the NHLBI because they help to improve training and experience of its researchers.