Brachial Artery: The continuation of the axillary artery; it branches into the radial and ulnar arteries.Arteries: The vessels carrying blood away from the heart.Vasodilation: The physiological widening of BLOOD VESSELS by relaxing the underlying VASCULAR SMOOTH MUSCLE.Forearm: Part of the arm in humans and primates extending from the ELBOW to the WRIST.Regional Blood Flow: The flow of BLOOD through or around an organ or region of the body.Endothelium, Vascular: Single pavement layer of cells which line the luminal surface of the entire vascular system and regulate the transport of macromolecules and blood components.Nitroglycerin: A volatile vasodilator which relieves ANGINA PECTORIS by stimulating GUANYLATE CYCLASE and lowering cytosolic calcium. It is also sometimes used for TOCOLYSIS and explosives.Hyperemia: The presence of an increased amount of blood in a body part or an organ leading to congestion or engorgement of blood vessels. Hyperemia can be due to increase of blood flow into the area (active or arterial), or due to obstruction of outflow of blood from the area (passive or venous).Carotid Arteries: Either of the two principal arteries on both sides of the neck that supply blood to the head and neck; each divides into two branches, the internal carotid artery and the external carotid artery.Radial Artery: The direct continuation of the brachial trunk, originating at the bifurcation of the brachial artery opposite the neck of the radius. Its branches may be divided into three groups corresponding to the three regions in which the vessel is situated, the forearm, wrist, and hand.Pulmonary Artery: The short wide vessel arising from the conus arteriosus of the right ventricle and conveying unaerated blood to the lungs.Femoral Artery: The main artery of the thigh, a continuation of the external iliac artery.Cerebral Arteries: The arterial blood vessels supplying the CEREBRUM.Blood Flow Velocity: A value equal to the total volume flow divided by the cross-sectional area of the vascular bed.Renal Artery: A branch of the abdominal aorta which supplies the kidneys, adrenal glands and ureters.Vasodilator Agents: Drugs used to cause dilation of the blood vessels.Mesenteric Arteries: Arteries which arise from the abdominal aorta and distribute to most of the intestines.Carotid Artery, Common: The two principal arteries supplying the structures of the head and neck. They ascend in the neck, one on each side, and at the level of the upper border of the thyroid cartilage, each divides into two branches, the external (CAROTID ARTERY, EXTERNAL) and internal (CAROTID ARTERY, INTERNAL) carotid arteries.Axillary Artery: The continuation of the subclavian artery; it distributes over the upper limb, axilla, chest and shoulder.Basilar Artery: The artery formed by the union of the right and left vertebral arteries; it runs from the lower to the upper border of the pons, where it bifurcates into the two posterior cerebral arteries.Ulnar Artery: The larger of the two terminal branches of the brachial artery, beginning about one centimeter distal to the bend of the elbow. Like the RADIAL ARTERY, its branches may be divided into three groups corresponding to their locations in the forearm, wrist, and hand.Ultrasonography, Doppler: Ultrasonography applying the Doppler effect, with frequency-shifted ultrasound reflections produced by moving targets (usually red blood cells) in the bloodstream along the ultrasound axis in direct proportion to the velocity of movement of the targets, to determine both direction and velocity of blood flow. (Stedman, 25th ed)Subclavian Artery: Artery arising from the brachiocephalic trunk on the right side and from the arch of the aorta on the left side. It distributes to the neck, thoracic wall, spinal cord, brain, meninges, and upper limb.Blood Pressure: PRESSURE of the BLOOD on the ARTERIES and other BLOOD VESSELS.Iliac Artery: Either of two large arteries originating from the abdominal aorta; they supply blood to the pelvis, abdominal wall and legs.Ultrasonography, Doppler, Pulsed: Ultrasonography applying the Doppler effect, with velocity detection combined with range discrimination. Short bursts of ultrasound are transmitted at regular intervals and the echoes are demodulated as they return.Vertebral Artery: The first branch of the SUBCLAVIAN ARTERY with distribution to muscles of the NECK; VERTEBRAE; SPINAL CORD; CEREBELLUM; and interior of the CEREBRUM.Coronary Artery Bypass: Surgical therapy of ischemic coronary artery disease achieved by grafting a section of saphenous vein, internal mammary artery, or other substitute between the aorta and the obstructed coronary artery distal to the obstructive lesion.Mammary Arteries: Arteries originating from the subclavian or axillary arteries and distributing to the anterior thoracic wall, mediastinal structures, diaphragm, pectoral muscles and mammary gland.Carotid Artery Diseases: Pathological conditions involving the CAROTID ARTERIES, including the common, internal, and external carotid arteries. ATHEROSCLEROSIS and TRAUMA are relatively frequent causes of carotid artery pathology.Carotid Artery, Internal: Branch of the common carotid artery which supplies the anterior part of the brain, the eye and its appendages, the forehead and nose.Compliance: Distensibility measure of a chamber such as the lungs (LUNG COMPLIANCE) or bladder. Compliance is expressed as a change in volume per unit change in pressure.Plethysmography: Recording of change in the size of a part as modified by the circulation in it.Arm: The superior part of the upper extremity between the SHOULDER and the ELBOW.Pulsatile Flow: Rhythmic, intermittent propagation of a fluid through a BLOOD VESSEL or piping system, in contrast to constant, smooth propagation, which produces laminar flow.Coronary Vessels: The veins and arteries of the HEART.Splenic Artery: The largest branch of the celiac trunk with distribution to the spleen, pancreas, stomach and greater omentum.Vasoconstriction: The physiological narrowing of BLOOD VESSELS by contraction of the VASCULAR SMOOTH MUSCLE.Catheterization, Peripheral: Insertion of a catheter into a peripheral artery, vein, or airway for diagnostic or therapeutic purposes.Hepatic Artery: A branch of the celiac artery that distributes to the stomach, pancreas, duodenum, liver, gallbladder, and greater A competitive inhibitor of nitric oxide synthetase.Angiography: Radiography of blood vessels after injection of a contrast medium.Cross-Over Studies: Studies comparing two or more treatments or interventions in which the subjects or patients, upon completion of the course of one treatment, are switched to another. In the case of two treatments, A and B, half the subjects are randomly allocated to receive these in the order A, B and half to receive them in the order B, A. A criticism of this design is that effects of the first treatment may carry over into the period when the second is given. (Last, A Dictionary of Epidemiology, 2d ed)Nitroprusside: A powerful vasodilator used in emergencies to lower blood pressure or to improve cardiac function. It is also an indicator for free sulfhydryl groups in proteins.Dilatation, Pathologic: The condition of an anatomical structure's being dilated beyond normal dimensions.Popliteal Artery: The continuation of the femoral artery coursing through the popliteal fossa; it divides into the anterior and posterior tibial arteries.Infusions, Intra-Arterial: Regional infusion of drugs via an arterial catheter. Often a pump is used to impel the drug through the catheter. Used in therapy of cancer, upper gastrointestinal hemorrhage, infection, and peripheral vascular disease.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Arteriovenous Shunt, Surgical: Surgical shunt allowing direct passage of blood from an artery to a vein. (From Dorland, 28th ed)Celiac Artery: The arterial trunk that arises from the abdominal aorta and after a short course divides into the left gastric, common hepatic and splenic arteries.Ophthalmic Artery: Artery originating from the internal carotid artery and distributing to the eye, orbit and adjacent facial structures.Arterial Occlusive Diseases: Pathological processes which result in the partial or complete obstruction of ARTERIES. They are characterized by greatly reduced or absence of blood flow through these vessels. They are also known as arterial insufficiency.Mesenteric Artery, Superior: A large vessel supplying the whole length of the small intestine except the superior part of the duodenum. It also supplies the cecum and the ascending part of the colon and about half the transverse part of the colon. It arises from the anterior surface of the aorta below the celiac artery at the level of the first lumbar vertebra.Nitric Oxide: A free radical gas produced endogenously by a variety of mammalian cells, synthesized from ARGININE by NITRIC OXIDE SYNTHASE. Nitric oxide is one of the ENDOTHELIUM-DEPENDENT RELAXING FACTORS released by the vascular endothelium and mediates VASODILATION. It also inhibits platelet aggregation, induces disaggregation of aggregated platelets, and inhibits platelet adhesion to the vascular endothelium. Nitric oxide activates cytosolic GUANYLATE CYCLASE and thus elevates intracellular levels of CYCLIC GMP.Vascular Resistance: The force that opposes the flow of BLOOD through a vascular bed. It is equal to the difference in BLOOD PRESSURE across the vascular bed divided by the CARDIAC OUTPUT.Treatment Outcome: Evaluation undertaken to assess the results or consequences of management and procedures used in combating disease in order to determine the efficacy, effectiveness, safety, and practicability of these interventions in individual cases or series.Hemodynamics: The movement and the forces involved in the movement of the blood through the CARDIOVASCULAR SYSTEM.Coronary Angiography: Radiography of the vascular system of the heart muscle after injection of a contrast medium.Vascular Diseases: Pathological processes involving any of the BLOOD VESSELS in the cardiac or peripheral circulation. They include diseases of ARTERIES; VEINS; and rest of the vasculature system in the body.Risk Factors: An aspect of personal behavior or lifestyle, environmental exposure, or inborn or inherited characteristic, which, on the basis of epidemiologic evidence, is known to be associated with a health-related condition considered important to prevent.Umbilical Arteries: Specialized arterial vessels in the umbilical cord. They carry waste and deoxygenated blood from the FETUS to the mother via the PLACENTA. In humans, there are usually two umbilical arteries but sometimes one.Middle Cerebral Artery: The largest of the cerebral arteries. It trifurcates into temporal, frontal, and parietal branches supplying blood to most of the parenchyma of these lobes in the CEREBRAL CORTEX. These are the areas involved in motor, sensory, and speech activities.Renal Artery Obstruction: Narrowing or occlusion of the RENAL ARTERY or arteries. It is due usually to ATHEROSCLEROSIS; FIBROMUSCULAR DYSPLASIA; THROMBOSIS; EMBOLISM, or external pressure. The reduced renal perfusion can lead to renovascular hypertension (HYPERTENSION, RENOVASCULAR).Thoracic Arteries: Arteries originating from the subclavian or axillary arteries and distributing to the anterior thoracic wall, mediastinal structures, diaphragm, pectoral muscles, mammary gland and the axillary aspect of the chest wall.Coronary Disease: An imbalance between myocardial functional requirements and the capacity of the CORONARY VESSELS to supply sufficient blood flow. It is a form of MYOCARDIAL ISCHEMIA (insufficient blood supply to the heart muscle) caused by a decreased capacity of the coronary vessels.Muscle, Smooth, Vascular: The nonstriated involuntary muscle tissue of blood vessels.Temporal Arteries: Arteries arising from the external carotid or the maxillary artery and distributing to the temporal region.Aneurysm: Pathological outpouching or sac-like dilatation in the wall of any blood vessel (ARTERIES or VEINS) or the heart (HEART ANEURYSM). It indicates a thin and weakened area in the wall which may later rupture. Aneurysms are classified by location, etiology, or other characteristics.Laser-Doppler Flowmetry: A method of non-invasive, continuous measurement of MICROCIRCULATION. The technique is based on the values of the DOPPLER EFFECT of low-power laser light scattered randomly by static structures and moving tissue particulates.Bronchial Arteries: Left bronchial arteries arise from the thoracic aorta, the right from the first aortic intercostal or the upper left bronchial artery; they supply the bronchi and the lower trachea.Atherosclerosis: A thickening and loss of elasticity of the walls of ARTERIES that occurs with formation of ATHEROSCLEROTIC PLAQUES within the ARTERIAL INTIMA.Vascular Patency: The degree to which BLOOD VESSELS are not blocked or obstructed.Crutches: Wooden or metal staffs designed to aid a person in walking. (UMDNS,1999)Aneurysm, False: Not an aneurysm but a well-defined collection of blood and CONNECTIVE TISSUE outside the wall of a blood vessel or the heart. It is the containment of a ruptured blood vessel or heart, such as sealing a rupture of the left ventricle. False aneurysm is formed by organized THROMBUS and HEMATOMA in surrounding tissue.Tunica Media: The middle layer of blood vessel walls, composed principally of thin, cylindrical, smooth muscle cells and elastic tissue. It accounts for the bulk of the wall of most arteries. The smooth muscle cells are arranged in circular layers around the vessel, and the thickness of the coat varies with the size of the vessel.Prospective Studies: Observation of a population for a sufficient number of persons over a sufficient number of years to generate incidence or mortality rates subsequent to the selection of the study group.Exercise: Physical activity which is usually regular and done with the intention of improving or maintaining PHYSICAL FITNESS or HEALTH. Contrast with PHYSICAL EXERTION which is concerned largely with the physiologic and metabolic response to energy expenditure.Injections, Intra-Arterial: Delivery of drugs into an artery.Heart Rate: The number of times the HEART VENTRICLES contract per unit of time, usually per minute.Acetylcholine: A neurotransmitter found at neuromuscular junctions, autonomic ganglia, parasympathetic effector junctions, a subset of sympathetic effector junctions, and at many sites in the central nervous system.Double-Blind Method: A method of studying a drug or procedure in which both the subjects and investigators are kept unaware of who is actually getting which specific treatment.Pulse: The rhythmical expansion and contraction of an ARTERY produced by waves of pressure caused by the ejection of BLOOD from the left ventricle of the HEART as it contracts.Vasoconstrictor Agents: Drugs used to cause constriction of the blood vessels.Veins: The vessels carrying blood away from the capillary beds.Administration, Sublingual: Administration of a soluble dosage form by placement under the tongue.Reference Values: The range or frequency distribution of a measurement in a population (of organisms, organs or things) that has not been selected for the presence of disease or abnormality.Vasomotor System: The neural systems which act on VASCULAR SMOOTH MUSCLE to control blood vessel diameter. The major neural control is through the sympathetic nervous system.Cardiovascular Diseases: Pathological conditions involving the CARDIOVASCULAR SYSTEM including the HEART; the BLOOD VESSELS; or the PERICARDIUM.Uterine Artery: A branch arising from the internal iliac artery in females, that supplies blood to the uterus.Hemorheology: The deformation and flow behavior of BLOOD and its elements i.e., PLASMA; ERYTHROCYTES; WHITE BLOOD CELLS; and BLOOD PLATELETS.Stents: Devices that provide support for tubular structures that are being anastomosed or for body cavities during skin grafting.Hypertension: Persistently high systemic arterial BLOOD PRESSURE. Based on multiple readings (BLOOD PRESSURE DETERMINATION), hypertension is currently defined as when SYSTOLIC PRESSURE is consistently greater than 140 mm Hg or when DIASTOLIC PRESSURE is consistently 90 mm Hg or more.Arteriosclerosis: Thickening and loss of elasticity of the walls of ARTERIES of all sizes. There are many forms classified by the types of lesions and arteries involved, such as ATHEROSCLEROSIS with fatty lesions in the ARTERIAL INTIMA of medium and large muscular arteries.Follow-Up Studies: Studies in which individuals or populations are followed to assess the outcome of exposures, procedures, or effects of a characteristic, e.g., occurrence of disease.Analysis of Variance: A statistical technique that isolates and assesses the contributions of categorical independent variables to variation in the mean of a continuous dependent variable.Hand Strength: Force exerted when gripping or grasping.Carotid Artery, External: Branch of the common carotid artery which supplies the exterior of the head, the face, and the greater part of the neck.Subclavian Steal Syndrome: A clinically significant reduction in blood supply to the BRAIN STEM and CEREBELLUM (i.e., VERTEBROBASILAR INSUFFICIENCY) resulting from reversal of blood flow through the VERTEBRAL ARTERY from occlusion or stenosis of the proximal subclavian or brachiocephalic artery. Common symptoms include VERTIGO; SYNCOPE; and INTERMITTENT CLAUDICATION of the involved upper extremity. Subclavian steal may also occur in asymptomatic individuals. (From J Cardiovasc Surg 1994;35(1):11-4; Acta Neurol Scand 1994;90(3):174-8)Tunica Intima: The innermost layer of an artery or vein, made up of one layer of endothelial cells and supported by an internal elastic lamina.Blood Pressure Determination: Techniques for measuring blood pressure.Tomography, X-Ray Computed: Tomography using x-ray transmission and a computer algorithm to reconstruct the image.Angioplasty, Balloon: Use of a balloon catheter for dilation of an occluded artery. It is used in treatment of arterial occlusive diseases, including renal artery stenosis and arterial occlusions in the leg. For the specific technique of BALLOON DILATION in coronary arteries, ANGIOPLASTY, BALLOON, CORONARY is available.Elasticity: Resistance and recovery from distortion of shape.Brachiocephalic Veins: Large veins on either side of the root of the neck formed by the junction of the internal jugular and subclavian veins. They drain blood from the head, neck, and upper extremities, and unite to form the superior vena cava.Norepinephrine: Precursor of epinephrine that is secreted by the adrenal medulla and is a widespread central and autonomic neurotransmitter. Norepinephrine is the principal transmitter of most postganglionic sympathetic fibers and of the diffuse projection system in the brain arising from the locus ceruleus. It is also found in plants and is used pharmacologically as a sympathomimetic.Carotid Artery Injuries: Damages to the CAROTID ARTERIES caused either by blunt force or penetrating trauma, such as CRANIOCEREBRAL TRAUMA; THORACIC INJURIES; and NECK INJURIES. Damaged carotid arteries can lead to CAROTID ARTERY THROMBOSIS; CAROTID-CAVERNOUS SINUS FISTULA; pseudoaneurysm formation; and INTERNAL CAROTID ARTERY DISSECTION. (From Am J Forensic Med Pathol 1997, 18:251; J Trauma 1994, 37:473)Hemostatic Techniques: Techniques for controlling bleeding.Coronary Circulation: The circulation of blood through the CORONARY VESSELS of the HEART.Ischemia: A hypoperfusion of the BLOOD through an organ or tissue caused by a PATHOLOGIC CONSTRICTION or obstruction of its BLOOD VESSELS, or an absence of BLOOD CIRCULATION.Biological Markers: Measurable and quantifiable biological parameters (e.g., specific enzyme concentration, specific hormone concentration, specific gene phenotype distribution in a population, presence of biological substances) which serve as indices for health- and physiology-related assessments, such as disease risk, psychiatric disorders, environmental exposure and its effects, disease diagnosis, metabolic processes, substance abuse, pregnancy, cell line development, epidemiologic studies, etc.Vascular Surgical Procedures: Operative procedures for the treatment of vascular disorders.Case-Control Studies: Studies which start with the identification of persons with a disease of interest and a control (comparison, referent) group without the disease. The relationship of an attribute to the disease is examined by comparing diseased and non-diseased persons with regard to the frequency or levels of the attribute in each group.Peripheral Vascular Diseases: Pathological processes involving any one of the BLOOD VESSELS in the vasculature outside the HEART.Upper Extremity: The region of the upper limb in animals, extending from the deltoid region to the HAND, and including the ARM; AXILLA; and SHOULDER.Stress, Mechanical: A purely physical condition which exists within any material because of strain or deformation by external forces or by non-uniform thermal expansion; expressed quantitatively in units of force per unit area.Carotid Intima-Media Thickness: A measurement of the thickness of the carotid artery walls. It is measured by B-mode ULTRASONOGRAPHY and is used as a surrogate marker for ATHEROSCLEROSIS.Constriction, Pathologic: The condition of an anatomical structure's being constricted beyond normal dimensions.Saphenous Vein: The vein which drains the foot and leg.Predictive Value of Tests: In screening and diagnostic tests, the probability that a person with a positive test is a true positive (i.e., has the disease), is referred to as the predictive value of a positive test; whereas, the predictive value of a negative test is the probability that the person with a negative test does not have the disease. Predictive value is related to the sensitivity and specificity of the test.Ligation: Application of a ligature to tie a vessel or strangulate a part.Dose-Response Relationship, Drug: The relationship between the dose of an administered drug and the response of the organism to the drug.Hypercholesterolemia: A condition with abnormally high levels of CHOLESTEROL in the blood. It is defined as a cholesterol value exceeding the 95th percentile for the population.Ultrasonography, Interventional: The use of ultrasound to guide minimally invasive surgical procedures such as needle ASPIRATION BIOPSY; DRAINAGE; etc. Its widest application is intravascular ultrasound imaging but it is useful also in urology and intra-abdominal conditions.Infarction, Middle Cerebral Artery: NECROSIS occurring in the MIDDLE CEREBRAL ARTERY distribution system which brings blood to the entire lateral aspects of each CEREBRAL HEMISPHERE. Clinical signs include impaired cognition; APHASIA; AGRAPHIA; weak and numbness in the face and arms, contralaterally or bilaterally depending on the infarction.Ascorbic Acid: A six carbon compound related to glucose. It is found naturally in citrus fruits and many vegetables. Ascorbic acid is an essential nutrient in human diets, and necessary to maintain connective tissue and bone. Its biologically active form, vitamin C, functions as a reducing agent and coenzyme in several metabolic pathways. Vitamin C is considered an antioxidant.Vascular System Injuries: Injuries to blood vessels caused by laceration, contusion, puncture, or crush and other types of injuries. Symptoms vary by site and mode of injuries and may include bleeding, bruising, swelling, pain, and numbness. It does not include injuries secondary to pathologic function or diseases such as ATHEROSCLEROSIS.Ultrasonography, Doppler, Color: Ultrasonography applying the Doppler effect, with the superposition of flow information as colors on a gray scale in a real-time image. This type of ultrasonography is well-suited to identifying the location of high-velocity flow (such as in a stenosis) or of mapping the extent of flow in a certain region.Exercise Test: Controlled physical activity which is performed in order to allow assessment of physiological functions, particularly cardiovascular and pulmonary, but also aerobic capacity. Maximal (most intense) exercise is usually required but submaximal exercise is also used.Lipids: A generic term for fats and lipoids, the alcohol-ether-soluble constituents of protoplasm, which are insoluble in water. They comprise the fats, fatty oils, essential oils, waxes, phospholipids, glycolipids, sulfolipids, aminolipids, chromolipids (lipochromes), and fatty acids. (Grant & Hackh's Chemical Dictionary, 5th ed)Retinal Artery Occlusion: Sudden ISCHEMIA in the RETINA due to blocked blood flow through the CENTRAL RETINAL ARTERY or its branches leading to sudden complete or partial loss of vision, respectively, in the eye.Anastomosis, Surgical: Surgical union or shunt between ducts, tubes or vessels. It may be end-to-end, end-to-side, side-to-end, or side-to-side.Photoplethysmography: Plethysmographic determination in which the intensity of light reflected from the skin surface and the red cells below is measured to determine the blood volume of the respective area. There are two types, transmission and reflectance.Cardiac Catheterization: Procedures in which placement of CARDIAC CATHETERS is performed for therapeutic or diagnostic procedures.Aorta: The main trunk of the systemic arteries.Carotid Artery Thrombosis: Blood clot formation in any part of the CAROTID ARTERIES. This may produce CAROTID STENOSIS or occlusion of the vessel, leading to TRANSIENT ISCHEMIC ATTACK; CEREBRAL INFARCTION; or AMAUROSIS FUGAX.Nitric Oxide Synthase: An NADPH-dependent enzyme that catalyzes the conversion of L-ARGININE and OXYGEN to produce CITRULLINE and NITRIC OXIDE.Microcirculation: The circulation of the BLOOD through the MICROVASCULAR NETWORK.Catheterization: Use or insertion of a tubular device into a duct, blood vessel, hollow organ, or body cavity for injecting or withdrawing fluids for diagnostic or therapeutic purposes. It differs from INTUBATION in that the tube here is used to restore or maintain patency in obstructions.Linear Models: Statistical models in which the value of a parameter for a given value of a factor is assumed to be equal to a + bx, where a and b are constants. The models predict a linear regression.Meningeal Arteries: Arteries which supply the dura mater.Retrospective Studies: Studies used to test etiologic hypotheses in which inferences about an exposure to putative causal factors are derived from data relating to characteristics of persons under study or to events or experiences in their past. The essential feature is that some of the persons under study have the disease or outcome of interest and their characteristics are compared with those of unaffected persons.Arginine: An essential amino acid that is physiologically active in the L-form.C-Reactive Protein: A plasma protein that circulates in increased amounts during inflammation and after tissue damage.Blood Circulation: The movement of the BLOOD as it is pumped through the CARDIOVASCULAR SYSTEM.Homocysteine: A thiol-containing amino acid formed by a demethylation of METHIONINE.Cholesterol, LDL: Cholesterol which is contained in or bound to low density lipoproteins (LDL), including CHOLESTEROL ESTERS and free cholesterol.Vascular Access Devices: Devices to be inserted into veins or arteries for the purpose of carrying fluids into or from a peripheral or central vascular location. They may include component parts such as catheters, ports, reservoirs, and valves. They may be left in place temporarily for therapeutic or diagnostic purposes.Renal Dialysis: Therapy for the insufficient cleansing of the BLOOD by the kidneys based on dialysis and including hemodialysis, PERITONEAL DIALYSIS, and HEMODIAFILTRATION.Blood Vessels: Any of the tubular vessels conveying the blood (arteries, arterioles, capillaries, venules, and veins).Carotid Stenosis: Narrowing or stricture of any part of the CAROTID ARTERIES, most often due to atherosclerotic plaque formation. Ulcerations may form in atherosclerotic plaques and induce THROMBUS formation. Platelet or cholesterol emboli may arise from stenotic carotid lesions and induce a TRANSIENT ISCHEMIC ATTACK; CEREBROVASCULAR ACCIDENT; or temporary blindness (AMAUROSIS FUGAX). (From Adams et al., Principles of Neurology, 6th ed, pp 822-3)Peripheral Arterial Disease: Lack of perfusion in the EXTREMITIES resulting from atherosclerosis. It is characterized by INTERMITTENT CLAUDICATION, and an ANKLE BRACHIAL INDEX of 0.9 or less.Constriction: The act of constricting.Ultrasonography: The visualization of deep structures of the body by recording the reflections or echoes of ultrasonic pulses directed into the tissues. Use of ultrasound for imaging or diagnostic purposes employs frequencies ranging from 1.6 to 10 megahertz.Wounds, Penetrating: Wounds caused by objects penetrating the skin.Reproducibility of Results: The statistical reproducibility of measurements (often in a clinical context), including the testing of instrumentation or techniques to obtain reproducible results. The concept includes reproducibility of physiological measurements, which may be used to develop rules to assess probability or prognosis, or response to a stimulus; reproducibility of occurrence of a condition; and reproducibility of experimental results.Dilatation: The act of dilating.Diabetic Angiopathies: VASCULAR DISEASES that are associated with DIABETES MELLITUS.Bradykinin: A nonapeptide messenger that is enzymatically produced from KALLIDIN in the blood where it is a potent but short-lived agent of arteriolar dilation and increased capillary permeability. Bradykinin is also released from MAST CELLS during asthma attacks, from gut walls as a gastrointestinal vasodilator, from damaged tissues as a pain signal, and may be a neurotransmitter.Risk Assessment: The qualitative or quantitative estimation of the likelihood of adverse effects that may result from exposure to specified health hazards or from the absence of beneficial influences. (Last, Dictionary of Epidemiology, 1988)Cerebral Angiography: Radiography of the vascular system of the brain after injection of a contrast medium.Endothelin-1: A 21-amino acid peptide produced in a variety of tissues including endothelial and vascular smooth-muscle cells, neurons and astrocytes in the central nervous system, and endometrial cells. It acts as a modulator of vasomotor tone, cell proliferation, and hormone production. (N Eng J Med 1995;333(6):356-63)Blood Vessel Prosthesis Implantation: Surgical insertion of BLOOD VESSEL PROSTHESES to repair injured or diseased blood vessels.Magnetic Resonance Angiography: Non-invasive method of vascular imaging and determination of internal anatomy without injection of contrast media or radiation exposure. The technique is used especially in CEREBRAL ANGIOGRAPHY as well as for studies of other vascular structures.Nitric Oxide Synthase Type III: A CALCIUM-dependent, constitutively-expressed form of nitric oxide synthase found primarily in ENDOTHELIAL CELLS.Enzyme Inhibitors: Compounds or agents that combine with an enzyme in such a manner as to prevent the normal substrate-enzyme combination and the catalytic reaction.Tourniquets: Devices for the compression of a blood vessel by application around an extremity to control the circulation and prevent the flow of blood to or from the distal area. (From Dorland, 28th ed)Musculocutaneous Nerve: A major nerve of the upper extremity. The fibers of the musculocutaneous nerve originate in the lower cervical spinal cord (usually C5 to C7), travel via the lateral cord of the brachial plexus, and supply sensory and motor innervation to the upper arm, elbow, and forearm.Leg: The inferior part of the lower extremity between the KNEE and the ANKLE.Swine, Miniature: Genetically developed small pigs for use in biomedical research. There are several strains - Yucatan miniature, Sinclair miniature, and Minnesota miniature.Aging: The gradual irreversible changes in structure and function of an organism that occur as a result of the passage of time.Muscle Contraction: A process leading to shortening and/or development of tension in muscle tissue. Muscle contraction occurs by a sliding filament mechanism whereby actin filaments slide inward among the myosin filaments.Regression Analysis: Procedures for finding the mathematical function which best describes the relationship between a dependent variable and one or more independent variables. In linear regression (see LINEAR MODELS) the relationship is constrained to be a straight line and LEAST-SQUARES ANALYSIS is used to determine the best fit. In logistic regression (see LOGISTIC MODELS) the dependent variable is qualitative rather than continuously variable and LIKELIHOOD FUNCTIONS are used to find the best relationship. In multiple regression, the dependent variable is considered to depend on more than a single independent variable.Maxillary Artery: A branch of the external carotid artery which distributes to the deep structures of the face (internal maxillary) and to the side of the face and nose (external maxillary).Single-Blind Method: A method in which either the observer(s) or the subject(s) is kept ignorant of the group to which the subjects are assigned.Embolectomy: Surgical removal of an obstructing clot or foreign material which has been transported from a distant vessel by the bloodstream. Removal of a clot at its original site is called THROMBECTOMY.Lower Extremity: The region of the lower limb in animals, extending from the gluteal region to the FOOT, and including the BUTTOCKS; HIP; and LEG.Osteoarthropathy, Primary Hypertrophic: A condition chiefly characterized by thickening of the skin of the head and distal extremities, deep folds and furrows of the skin of the forehead, cheeks, and scalp, SEBORRHEA; HYPERHIDROSIS; periostosis of the long bones, digital clubbing, and spadelike enlargement of the hands and feet. It is more prevalent in the male, and is usually first evident during adolescence. Inheritance is primarily autosomal recessive, but an autosomal dominant form exists.Diagnostic Techniques, Cardiovascular: Methods and procedures for the diagnosis of diseases or dysfunction of the cardiovascular system or its organs or demonstration of their physiological processes.Models, Cardiovascular: Theoretical representations that simulate the behavior or activity of the cardiovascular system, processes, or phenomena; includes the use of mathematical equations, computers and other electronic equipment.Severity of Illness Index: Levels within a diagnostic group which are established by various measurement criteria applied to the seriousness of a patient's disorder.Hand: The distal part of the arm beyond the wrist in humans and primates, that includes the palm, fingers, and thumb.Blood Glucose: Glucose in blood.Electrocardiography: Recording of the moment-to-moment electromotive forces of the HEART as projected onto various sites on the body's surface, delineated as a scalar function of time. The recording is monitored by a tracing on slow moving chart paper or by observing it on a cardioscope, which is a CATHODE RAY TUBE DISPLAY.Carotid Artery, Internal, Dissection: The splitting of the vessel wall in one or both (left and right) internal carotid arteries (CAROTID ARTERY, INTERNAL). Interstitial hemorrhage into the media of the vessel wall can lead to occlusion of the internal carotid artery and aneurysm formation.Multivariate Analysis: A set of techniques used when variation in several variables has to be studied simultaneously. In statistics, multivariate analysis is interpreted as any analytic method that allows simultaneous study of two or more dependent variables.Thrombosis: Formation and development of a thrombus or blood clot in the blood vessel.Pulse Wave Analysis: Evaluation of the contour of the PULSE waves which vary in different parts of the circulation and depend on physiological as well as pathophysiological conditions of the individual.Hydroxymethylglutaryl-CoA Reductase Inhibitors: Compounds that inhibit HMG-CoA reductases. They have been shown to directly lower cholesterol synthesis.Punctures: Incision of tissues for injection of medication or for other diagnostic or therapeutic procedures. Punctures of the skin, for example may be used for diagnostic drainage; of blood vessels for diagnostic imaging procedures.Nails, Malformed: Deformities in nail structure or appearance, including hypertrophy, splitting, clubbing, furrowing, etc. Genetic diseases such as PACHYONYCHIA CONGENITA can result in malformed nails.Muscle Relaxation: That phase of a muscle twitch during which a muscle returns to a resting position.Coronary Artery Bypass, Off-Pump: Coronary artery bypass surgery on a beating HEART without a CARDIOPULMONARY BYPASS (diverting the flow of blood from the heart and lungs through an oxygenator).Internal Mammary-Coronary Artery Anastomosis: Direct myocardial revascularization in which the internal mammary artery is anastomosed to the right coronary artery, circumflex artery, or anterior descending coronary artery. The internal mammary artery is the most frequent choice, especially for a single graft, for coronary artery bypass surgery.Dogs: The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)Coronary Stenosis: Narrowing or constriction of a coronary artery.Coronary Artery Disease: Pathological processes of CORONARY ARTERIES that may derive from a congenital abnormality, atherosclerotic, or non-atherosclerotic cause.Cross-Sectional Studies: Studies in which the presence or absence of disease or other health-related variables are determined in each member of the study population or in a representative sample at one particular time. This contrasts with LONGITUDINAL STUDIES which are followed over a period of time.Diabetes Mellitus, Type 2: A subclass of DIABETES MELLITUS that is not INSULIN-responsive or dependent (NIDDM). It is characterized initially by INSULIN RESISTANCE and HYPERINSULINEMIA; and eventually by GLUCOSE INTOLERANCE; HYPERGLYCEMIA; and overt diabetes. Type II diabetes mellitus is no longer considered a disease exclusively found in adults. Patients seldom develop KETOSIS but often exhibit OBESITY.Vascular Stiffness: Loss of vascular ELASTICITY due to factors such as AGING; and ARTERIOSCLEROSIS. Increased arterial stiffness is one of the RISK FACTORS for many CARDIOVASCULAR DISEASES.Myocardial Infarction: NECROSIS of the MYOCARDIUM caused by an obstruction of the blood supply to the heart (CORONARY CIRCULATION).Vertebral Artery Dissection: Splitting of the vessel wall in the VERTEBRAL ARTERY. Interstitial hemorrhage into the media of the vessel wall can lead to occlusion of the vertebral artery, aneurysm formation, or THROMBOEMBOLISM. Vertebral artery dissection is often associated with TRAUMA and injuries to the head-neck region but can occur spontaneously.