View clinical trials related to Coronary Disease.
Filter by:This study will assess the value of magnetic resonance imaging (MRI) in detecting heart attack and heart attack risk in patients who come to the hospital emergency room because of chest pain. It will also investigate whether MRI can help predict the coronary status of patients 4 to 6 weeks and 1 year after emergency room admission. Patients who come to the emergency room of Suburban Hospital in Bethesda, MD, because of chest pain may be asked to enroll in this study if they have not been diagnosed as having a heart attack. Participating patients will undergo a MRI scan as soon as emergency room doctors determine they are in stable condition. For this procedure, the patient lies on a table that slides into the MRI scanner-a large tubular machine with a magnetic field. During the scan, a contrast material is injected into the vein. This material brightens the image of the heart so that the blood flow can be seen. The scan will show if there are areas of heart muscle that received insufficient blood flow. A second scan will be done within 72 hours to look for coronary artery blockage that may require treatment. Patients will be followed by telephone 4 to 8 weeks after the scans and again 1 year after the scans to ask about any significant medical problems that may have occurred during those time periods. This study will provide information that may improve emergency treatment of patients with acute chest pain by clarifying which patients require immediate medical treatment, which should be admitted to the hospital for further evaluation, and which may safely be discharged from the hospital.
Coronary artery disease (CAD) can cause poor blood flow and supply to the heart muscle. It can result in irreversible damage to the heart muscle and poor function. Before treating patients with heart disease it is important to know how well the heart is functioning. Echocardiography is a diagnostic test that can measure heart function. If part of the heart muscle is not working properly due to previous damage, echocardiography can provide information about how much improvement can be expected after treatment (surgery or angioplasty). The purpose of this study is to compare the accuracy of myocardial contrast echocardiography (MCE) to dobutamine echocardiography to detect the potential for damaged heart muscle to be treated and function in patients with heart disease. Myocardial contrast echocardiography (MCE) does not use radioactivity. It uses sound waves like standard echocardiography. However, with MCE patients receive an injection of a "contrast agent" directly into the blood stream through a vein. The contrast agent, called Optison, is made of tiny microbubbles smaller than red blood cells. The echocardiogram can detect these microbubbles in the small blood vessels of the heart muscle and allow researchers to find areas of the heart receiving less blood flow than others. Echocardiography with Dobutamine does not use radioactivity. It uses sound waves, like standard echocardiography. During this echocardiogram patients receive doses of a medication called dobutamine that stimulates the heart to beat stronger and faster. Heart muscle that does not beat stronger after dobutamine is probably dead, usually as a result of a previous heart attack.
This study is designed to compare two different echocardiographic techniques in the evaluation of heart disease (coronary artery disease). Both tests called Myocardial Contrast Echocardiography with Pharmacologic Stress and Stress Echocardiography with Dobutamine, are performed using a standard echocardiographic machine. Myocardial Contrast Echocardiography (MCE) does not use radioactivity. It uses sound waves like standard echocardiography. However, with MCE patients receive an injection of a "contrast agent" directly into the blood stream through a vein. The contrast agent, called Optison, is made of tiny microbubbles smaller than red blood cells. The echocardiogram can detect these microbubbles in the small blood vessels of the heart muscle and allow researchers to find areas of the heart receiving less blood flow than others. It is important to observe the heart during exercise because there are changes in blood flow. Since MCE cannot be performed when the patient is exercising, researchers give medication (adenosine) that stimulates the heart and creates a situation similar to exercise. Stress Echocardiography with Dobutamine does not use radioactivity. It uses sound waves like standard echocardiography. During this echocardiogram patients receive doses of a medication called dobutamine that stimulates the heart to beat stronger and faster. The purpose of this study is to evaluate the accuracy of MCE compared to stress echocardiography at detecting coronary artery disease (CAD).
An echocardiogram is an ultrasound technique used to gather information about the heart. Standard echocardiograms create images of the heart in two dimensions, thereby named 2D (two-dimensional) echocardiography. A new technique has been developed allowing images to be taken of the heart in three dimensions (real time 3D echocardiography). The 3D echocardiogram uses high frequency sound waves to see and record the movement and function of the heart muscle. The echocardiogram is taken by placing an instrument called a transducer against the chest wall over the heart. In this study patients will undergo a dobutamine stress echocardiogram. Dobutamine is drug that causes the heart to beat stronger and faster, similar to how it acts when exercising. Dobutamine allows researchers to tell if the heart is suffering from a lack of oxygen during exercise or other forms of stress, or if it is permanently damaged. The purpose of this study is to determine whether stress 3D echocardiography is feasible and accurate in the detection of heart disease (coronary artery disease). Results of the 3D echocardiogram will be compared to results from standard 2D echocardiograms.
Electron beam computed tomography (EBCT) has been regarded as the state-of-the-art investigation for detecting and quantitating coronary artery calcification. However, EBCT is expensive, and the asymmetric gantry geometry makes it less useful for routine scanning; thus, EBCT is not readily available to the general population. Recent reports have shown that "volumetric" (also known as "helical" or "spiral") scanners, which are much more commonly available than EBCT, can detect coronary artery calcifications. Updated software available to the NIH which will allow for EKG gating of volumetric scans should improve the quality of the images, and thus improve the ability to accurately quantitate coronary calcification by volumetric scanners. We would like to compare the results of volumetric scans with that of standard EBCT in order to characterize similarities and differences between the two scanning techniques. We propose to obtain EBCT and volumetric CT scans of the coronary arteries in a group of patients with known or suspected coronary artery disease and to calculate the calcium score by each method. Our primary analysis will be a comparison of the sensitivities of the two methods.
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 is especially useful when studying the arteries of the heart (CMRA, coronary magnetic resonance angiography). In this study researchers from several laboratories and hospitals will work together to determine the safety and effectiveness of CMRA with MS-325. MS-325 is a contrast agent. It is given to patients undergoing CRMA in order to improve the appearance of the arteries of the heart.
Blood flows to areas of the heart providing oxygen and fuel to the pumping muscle. Occasionally the arteries providing the fuel can become blocked. This occurs in coronary artery disease. Magnetic resonance imaging (MRI) can be used to evaluate the blood flow to different areas of the heart muscle. In this study magnetic resonance imaging will be compared to other diagnostic tests (radionucleotide perfusion studies) capable of measuring blood flow to heart muscle.
The purpose of this study is to investigate whether the susceptibility of subjects to atherosclerosis is influenced by prior CMV exposure, whether the susceptability to endothelial dysfunction in patients with and in patients without atherosclerosis is influenced by prior CMV exposure.
The walls of blood vessels are lined by flat cells that are responsible for releasing substance(s) that control the activity of the blood vessel. These cells are referred to as the endothelium of the blood vessel. One of the substances released from the endothelium is called nitric oxide (NO). This substance functions to keep blood vessels relaxed and to prevent blood from clotting inside the vessels. Studies done by researchers in the Cardiology Branch of the National Heart, Lung and Blood Institute have shown that nitric oxide activity may be lower in patients with hardening of the arteries (atherosclerosis) and risk factors for atherosclerosis. Another substance released by the cells of the endothelium is called bradykinin. It functions to stimulate the production of nitric oxide. Therefore bradykinin is also responsible for the relaxation and widening of blood vessels. An enzyme found in the blood called angiotensin-converting enzyme (ACE) inactivates baradykinin and thereby decreases the production of nitric oxide. The activity of ACE is determined by genetics and is different in each person. Medications that block ACE (ACE-inhibitors) may be useful for patients with high levels of ACE activity. This study is designed to determine; 1. The role of bradkinin in stimulating the production of nitric oxide 2. Whether ACE-inhibitors improve blood vessel relaxation caused by bradykinin 3. Whether ACE-inhibitors improve abnormal blood vessel relaxation 4. Whether ACE-inhibitors and bradykinin affect blood clotting 5. Whether blood vessel response to ACE-inhibitor and bradykinin depends on the patients genetic make-up
Myocardial ischemia is a heart condition in which not enough blood supply and oxygen reaches the heart muscle. Damage to the major blood vessels of the heart (coronary artery disease), minor blood vessels of the heart (microvascular heart disease), or damage to the heart muscle (hypertrophic cardiomyopathy) can cause myocardial ischemia. Any of theses three conditions can cause patients to experience chest pain and other symptoms as well as cause the heart to function improperly. In order to detect myocardial ischemia researchers can use tests to measure the movement of the walls of the heart. Walls receiving inadequate supplies of blood often move less and occasionally move in the opposite direction. Some of the tests may require patients to receive injections of radioactive tracers. The radioactive material acts to enhance 3 dimensional pictures of the heart and helps to identify areas of ischemia. The purpose of this study is to determine whether 3-dimensional imaging (tomography) with radioactive tracers can provide more important information about heart wall function than routine diagnostic tests.