View clinical trials related to Coronary Artery Disease.
Filter by:Patients with narrowed heart arteries who undergo coronary angiography (imaging of the heart's blood vessels) may participate in this "heart mapping" study designed to gain information about the condition of different areas of the heart muscle. In coronary angiography, a thin tube called a catheter is inserted through a small incision in the groin and pushed up to the heart. There, a contrast dye is injected, revealing areas of blockage in the coronary arteries-the vessels that supply blood to the heart muscle. As soon as the angiography is completed, patients in this study will undergo another procedure called "Biosense mapping." For this procedure, a special catheter with a tiny sensor at the tip will be inserted into the sheath that was used for the angiography and advanced to the heart's main pumping chamber-the left ventricle. The sensor detects the pattern of an electromagnetic field generated from a pad under the patient, and an image of the precise location of the catheter in 3-dimensional space can be seen on a computer screen. The catheter is then navigated to various precise locations in the ventricle, producing an electromechanical map that distinguishes scarred muscle tissue from healthy tissue-information that can be important in guiding treatment. When this mapping is completed, the patient will be given a drug called dobutamine to increase the heartbeat, and the mapping will be repeated. The heart may also be mapped while the heart rate is increased with a pacing catheter to simulate exercise. The test will be stopped if adverse side effects develop. Patients in the study will also have magnetic resonance imaging (MRI) and PET (positron emission tomography) scans to get additional information about the heart muscle, such as blood flow and metabolism rate.
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 human heart is divided into four chambers. One of the four chambers, the left ventricle, is the chamber mainly responsible for pumping blood out of the heart into circulation. Hypertrophic cardiomyopathy (HCM) is a genetically inherited disease causing an abnormal thickening of the heart muscle, especially the muscle making up the left ventricle. When the left ventricle becomes abnormally large it is called left ventricular hypertrophy (LVH). This condition can cause symptoms of chest pain, shortness of breath, fatigue, and heart beat palpitations. This study is designed to compare the ability of two drugs (enalapril and losartan) to improve symptoms and heart function of patients diagnosed with hypertrophic cardiomyopathy (HCM). Researchers have decided to compare these drugs because each one has been used to treat patients with other diseases causing thickening of the heart muscle. In these other conditions, enalapril and losartan have improved symptoms, decreased the thickness of heart muscle, improved blood flow and supply to the heart muscle, and improved the pumping action of the heart muscle. In this study researchers will compare the effectiveness of enalapril and losartan when given separately and together to patients with hypertrophic cardiomyopathy (HCM).
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