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Coronary Flow Reserve
Coronary flow reserve (CFR) is the maximum increase in blood flow through the coronary arteries above the normal resting volume. Its measurement is often used in medicine to assist in the treatment of conditions affecting the coronary arteries and to determine the efficacy of treatments used. Overview When demand for oxygen in the myocardium is increased, the vascular resistance of the coronary arteries has the ability to reduce, and this can increase the volume of blood passing through the blood vessels. This reduction occurs because the arteries dilate, which causes an increase in the diameter of the lumen. The greatest potential for this change is normally in the branches (arterioles) of the coronary artery that penetrate the myocardium, rather than those on the surface of the heart. Measurement Coronary flow reserve can be measured through a variety of methods, including digital subtraction cineangiography with coronary catheterization, doppler echocardiography, and positro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coronary Arteries
The coronary arteries are the arterial blood vessels of coronary circulation, which transport oxygenated blood to the heart muscle. The heart requires a continuous supply of oxygen to function and survive, much like any other tissue or organ of the body. The coronary arteries wrap around the entire heart. The two main branches are the left coronary artery and right coronary artery. The arteries can additionally be categorized based on the area of the heart for which they provide circulation. These categories are called ''epicardial'' (above the epicardium, or the outermost tissue of the heart) and ''microvascular'' (close to the endocardium, or the innermost tissue of the heart). Reduced function of the coronary arteries can lead to decreased flow of oxygen and nutrients to the heart. Not only does this affect supply to the heart muscle itself, but it also can affect the ability of the heart to pump blood throughout the body. Therefore, any disorder or disease of the coronary ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Positron Emission Tomography
Positron emission tomography (PET) is a functional imaging technique that uses radioactive substances known as radiotracers to visualize and measure changes in Metabolism, metabolic processes, and in other physiological activities including blood flow, regional chemical composition, and absorption. Different tracers are used for various imaging purposes, depending on the target process within the body. For example, 18F-FDG, -FDG is commonly used to detect cancer, Sodium fluoride#Medical imaging, NaF is widely used for detecting bone formation, and Isotopes of oxygen#Oxygen-15, oxygen-15 is sometimes used to measure blood flow. PET is a common medical imaging, imaging technique, a Scintigraphy#Process, medical scintillography technique used in nuclear medicine. A radiopharmaceutical, radiopharmaceutical — a radioisotope attached to a drug — is injected into the body as a radioactive tracer, tracer. When the radiopharmaceutical undergoes beta plus decay, a positron is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coronary Artery
The coronary arteries are the arterial blood vessels of coronary circulation, which transport oxygenated blood to the heart muscle. The heart requires a continuous supply of oxygen to function and survive, much like any other tissue or organ of the body. The coronary arteries wrap around the entire heart. The two main branches are the left coronary artery and right coronary artery. The arteries can additionally be categorized based on the area of the heart for which they provide circulation. These categories are called ''epicardial'' (above the epicardium, or the outermost tissue of the heart) and ''microvascular'' (close to the endocardium, or the innermost tissue of the heart). Reduced function of the coronary arteries can lead to decreased flow of oxygen and nutrients to the heart. Not only does this affect supply to the heart muscle itself, but it also can affect the ability of the heart to pump blood throughout the body. Therefore, any disorder or disease of the coronary ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anderson-Fabry Disease
Fabry disease, also known as Anderson–Fabry disease, is a rare genetic disease that can affect many parts of the body, including the kidneys, heart, and skin. Fabry disease is one of a group of conditions known as lysosomal storage diseases. The genetic mutation that causes Fabry disease interferes with the function of an enzyme that processes biomolecules known as sphingolipids, leading to these substances building up in the walls of blood vessels and other organs. It is inherited in an X-linked manner. Fabry disease is sometimes diagnosed using a blood test that measures the activity of the affected enzyme called alpha-galactosidase, but genetic testing is also sometimes used, particularly in females. The treatment for Fabry disease varies depending on the organs affected by the condition, and the underlying cause can be addressed by replacing the enzyme that is lacking. The first descriptions of the condition were made simultaneously by dermatologist Johannes Fabry and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stenosis
A stenosis (from Ancient Greek στενός, "narrow") is an abnormal narrowing in a blood vessel or other tubular organ or structure such as foramina and canals. It is also sometimes called a stricture (as in urethral stricture). ''Stricture'' as a term is usually used when narrowing is caused by contraction of smooth muscle (e.g. achalasia, prinzmetal angina); ''stenosis'' is usually used when narrowing is caused by lesion that reduces the space of lumen (e.g. atherosclerosis). The term coarctation is another synonym, but is commonly used only in the context of aortic coarctation. Restenosis is the recurrence of stenosis after a procedure. Types The resulting syndrome depends on the structure affected. Examples of vascular stenotic lesions include: * Intermittent claudication (peripheral artery stenosis) * Angina ( coronary artery stenosis) * Carotid artery stenosis which predispose to (strokes and transient ischaemic episodes) * Renal artery stenosis The types of sten ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vasodilator
Vasodilation is the widening of blood vessels. It results from relaxation of smooth muscle cells within the vessel walls, in particular in the large veins, large arteries, and smaller arterioles. The process is the opposite of vasoconstriction, which is the narrowing of blood vessels. When blood vessels dilate, the flow of blood is increased due to a decrease in vascular resistance and increase in cardiac output. Therefore, dilation of arterial blood vessels (mainly the arterioles) decreases blood pressure. The response may be intrinsic (due to local processes in the surrounding tissue) or extrinsic (due to hormones or the nervous system). In addition, the response may be localized to a specific organ (depending on the metabolic needs of a particular tissue, as during strenuous exercise), or it may be systemic (seen throughout the entire systemic circulation). Endogenous substances and drugs that cause vasodilation are termed vasodilators. Such vasoactivity is necessary for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cardiac Syndrome X
Microvascular angina, previously known as cardiac syndrome X, is Angina pectoris, angina (chest pain) with signs associated with decreased blood flow to heart tissue but with normal coronary artery, coronary arteries. The use of the term CSX can lead to the lack of appreciation of how microvascular angina is a debilitating heart related pain condition with the increased risk of heart attack and other heart problems. Many mainly women can have difficulty accessing the specialist care of a cardiologist for this reason. Some studies have found increased risk of other vasospastic disorders in cardiac microvascular angina patients, such as migraine and Raynaud's phenomenon. It is treated with Beta blocker, beta-blockers, such as metoprolol however beta blockers can make coronary spasms worse. This is a distinct diagnosis from variant angina. Signs and symptoms While there is no formal definition of microvascular angina, the general consensus is that it entails all of the following: * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coronary Artery Disease
Coronary artery disease (CAD), also called coronary heart disease (CHD), ischemic heart disease (IHD), myocardial ischemia, or simply heart disease, involves the reduction of blood flow to the heart muscle due to build-up of atherosclerotic plaque An atheroma, or atheromatous plaque, is an abnormal and reversible accumulation of material in the inner layer of an arterial wall. The material consists of mostly macrophage cells, or debris, containing lipids, calcium and a variable amount ... in the arteries of the heart. It is the most common of the cardiovascular diseases. Types include stable angina, unstable angina, myocardial infarction, and sudden cardiac death. A common symptom is chest pain or discomfort which may travel into the shoulder, arm, back, neck, or jaw. Occasionally it may feel like heartburn. Usually symptoms occur with exercise or emotional Stress (psychological), stress, last less than a few minutes, and improve with rest. Shortness of breath may also o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Doppler Echocardiography
Doppler echocardiography is a procedure that uses Doppler ultrasonography to examine the heart. An echocardiogram uses high frequency sound waves to create an image of the heart while the use of Doppler technology allows determination of the speed and direction of blood flow by utilizing the Doppler effect. An echocardiogram can, within certain limits, produce accurate assessment of the direction of blood flow and the velocity of blood and cardiac tissue at any arbitrary point using the Doppler effect. One of the limitations is that the ultrasound beam should be as parallel to the blood flow as possible. Velocity measurements allow assessment of cardiac valve areas and function, any abnormal communications between the left and right side of the heart, any leaking of blood through the valves (valvular regurgitation), calculation of the cardiac output and calculation of E/A ratio [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myocardium
Cardiac muscle (also called heart muscle, myocardium, cardiomyocytes and cardiac myocytes) is one of three types of vertebrate muscle tissues, with the other two being skeletal muscle and smooth muscle. It is an involuntary, striated muscle that constitutes the main tissue of the wall of the heart. The cardiac muscle (myocardium) forms a thick middle layer between the outer layer of the heart wall (the pericardium) and the inner layer (the endocardium), with blood supplied via the coronary circulation. It is composed of individual cardiac muscle cells joined by intercalated discs, and encased by collagen fibers and other substances that form the extracellular matrix. Cardiac muscle contracts in a similar manner to skeletal muscle, although with some important differences. Electrical stimulation in the form of a cardiac action potential triggers the release of calcium from the cell's internal calcium store, the sarcoplasmic reticulum. The rise in calcium causes the cell's m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coronary Catheterization
A coronary catheterization is a minimally invasive procedure to access the coronary circulation and blood filled chambers of the heart using a catheter. It is performed for both diagnostic and interventional (treatment) purposes. Coronary catheterization is one of the several cardiology diagnostic tests and procedures. Specifically, through the injection of a liquid radiocontrast agent and illumination with X-rays, angiocardiography allows the recognition of Vascular occlusion, occlusion, stenosis, restenosis, thrombosis or aneurysmal enlargement of the coronary artery lumen (anatomy), lumens; heart chamber size; heart muscle contraction performance; and some aspects of heart valve function. Important internal heart and lung blood pressures, not measurable from outside the body, can be accurately measured during the test. The relevant problems that the test deals with most commonly occur as a result of advanced atherosclerosis – atheroma activity within the wall of the coronary ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cineangiography
Angiography or arteriography is a medical imaging technique used to visualize the inside, or lumen, of blood vessels and organs of the body, with particular interest in the arteries, veins, and the heart chambers. Modern angiography is performed by injecting a radio-opaque contrast agent into the blood vessel and imaging using X-ray based techniques such as fluoroscopy. The word itself comes from the Greek words ἀγγεῖον ''angeion'' 'vessel' and γράφειν ''graphein'' 'to write, record'. The film or image of the blood vessels is called an ''angiograph'', or more commonly an ''angiogram''. Though the word can describe both an arteriogram and a venogram, in everyday usage the terms angiogram and arteriogram are often used synonymously, whereas the term venogram is used more precisely. The term angiography has been applied to radionuclide angiography and newer vascular imaging techniques such as CO2 angiography, CT angiography and MR angiography. The term ''isotope a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
