Loading...
Blood Pressure Determination: Techniques for measuring blood pressure.Blood Pressure: PRESSURE of the BLOOD on the ARTERIES and other BLOOD VESSELS.Pressure: A type of stress exerted uniformly in all directions. Its measure is the force exerted per unit area. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)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.Blood Pressure Monitoring, Ambulatory: Method in which repeated blood pressure readings are made while the patient undergoes normal daily activities. It allows quantitative analysis of the high blood pressure load over time, can help distinguish between types of HYPERTENSION, and can assess the effectiveness of antihypertensive therapy.Heart Rate: The number of times the HEART VENTRICLES contract per unit of time, usually per minute.Antihypertensive Agents: Drugs used in the treatment of acute or chronic vascular HYPERTENSION regardless of pharmacological mechanism. Among the antihypertensive agents are DIURETICS; (especially DIURETICS, THIAZIDE); ADRENERGIC BETA-ANTAGONISTS; ADRENERGIC ALPHA-ANTAGONISTS; ANGIOTENSIN-CONVERTING ENZYME INHIBITORS; CALCIUM CHANNEL BLOCKERS; GANGLIONIC BLOCKERS; and VASODILATOR AGENTS.Hydrostatic Pressure: The pressure due to the weight of fluid.Blood Pressure Monitors: Devices for continuously measuring and displaying the arterial blood pressure.Systole: Period of contraction of the HEART, especially of the HEART VENTRICLES.Hemodynamics: The movement and the forces involved in the movement of the blood through the CARDIOVASCULAR SYSTEM.Diastole: Post-systolic relaxation of the HEART, especially the HEART VENTRICLES.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Hypotension: Abnormally low BLOOD PRESSURE that can result in inadequate blood flow to the brain and other vital organs. Common symptom is DIZZINESS but greater negative impacts on the body occur when there is prolonged depravation of oxygen and nutrients.Intracranial Pressure: Pressure within the cranial cavity. It is influenced by brain mass, the circulatory system, CSF dynamics, and skull rigidity.Renin: A highly specific (Leu-Leu) endopeptidase that generates ANGIOTENSIN I from its precursor ANGIOTENSINOGEN, leading to a cascade of reactions which elevate BLOOD PRESSURE and increase sodium retention by the kidney in the RENIN-ANGIOTENSIN SYSTEM. The enzyme was formerly listed as EC 3.4.99.19.Intraocular Pressure: The pressure of the fluids in the eye.Rats, Inbred SHR: A strain of Rattus norvegicus with elevated blood pressure used as a model for studying hypertension and stroke.Arterial Pressure: The blood pressure in the ARTERIES. It is commonly measured with a SPHYGMOMANOMETER on the upper arm which represents the arterial pressure in the BRACHIAL ARTERY.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.Transducers, Pressure: Transducers that are activated by pressure changes, e.g., blood pressure.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.Kidney: Body organ that filters blood for the secretion of URINE and that regulates ion concentrations.Circadian Rhythm: The regular recurrence, in cycles of about 24 hours, of biological processes or activities, such as sensitivity to drugs and stimuli, hormone secretion, sleeping, and feeding.Sympathetic Nervous System: The thoracolumbar division of the autonomic nervous system. Sympathetic preganglionic fibers originate in neurons of the intermediolateral column of the spinal cord and project to the paravertebral and prevertebral ganglia, which in turn project to target organs. The sympathetic nervous system mediates the body's response to stressful situations, i.e., the fight or flight reactions. It often acts reciprocally to the parasympathetic system.Atmospheric Pressure: The pressure at any point in an atmosphere due solely to the weight of the atmospheric gases above the point concerned.Venous Pressure: The blood pressure in the VEINS. It is usually measured to assess the filling PRESSURE to the HEART VENTRICLE.Sex Determination Processes: The mechanisms by which the SEX of an individual's GONADS are fixed.Air Pressure: The force per unit area that the air exerts on any surface in contact with it. Primarily used for articles pertaining to air pressure within a closed environment.Sphygmomanometers: Instruments for measuring arterial blood pressure consisting of an inflatable cuff, inflating bulb, and a gauge showing the blood pressure. (Stedman, 26th ed)Cardiovascular Diseases: Pathological conditions involving the CARDIOVASCULAR SYSTEM including the HEART; the BLOOD VESSELS; or the PERICARDIUM.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.Cardiovascular System: The HEART and the BLOOD VESSELS by which BLOOD is pumped and circulated through the body.Hypertension, Renal: Persistent high BLOOD PRESSURE due to KIDNEY DISEASES, such as those involving the renal parenchyma, the renal vasculature, or tumors that secrete RENIN.Baroreflex: A response by the BARORECEPTORS to increased BLOOD PRESSURE. Increased pressure stretches BLOOD VESSELS which activates the baroreceptors in the vessel walls. The net response of the CENTRAL NERVOUS SYSTEM is a reduction of central sympathetic outflow. This reduces blood pressure both by decreasing peripheral VASCULAR RESISTANCE and by lowering CARDIAC OUTPUT. Because the baroreceptors are tonically active, the baroreflex can compensate rapidly for both increases and decreases in blood pressure.Sodium Chloride, Dietary: Sodium chloride used in foods.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.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.Rats, Inbred WKY: A strain of Rattus norvegicus used as a normotensive control for the spontaneous hypertensive rats (SHR).Body Weight: The mass or quantity of heaviness of an individual. It is expressed by units of pounds or kilograms.Diet, Sodium-Restricted: A diet which contains very little sodium chloride. It is prescribed by some for hypertension and for edematous states. (Dorland, 27th ed)Regional Blood Flow: The flow of BLOOD through or around an organ or region of the body.Ventricular Pressure: The pressure within a CARDIAC VENTRICLE. Ventricular pressure waveforms can be measured in the beating heart by catheterization or estimated using imaging techniques (e.g., DOPPLER ECHOCARDIOGRAPHY). The information is useful in evaluating the function of the MYOCARDIUM; CARDIAC VALVES; and PERICARDIUM, particularly with simultaneous measurement of other (e.g., aortic or atrial) pressures.Sodium, Dietary: Sodium or sodium compounds used in foods or as a food. The most frequently used compounds are sodium chloride or sodium glutamate.Body Mass Index: An indicator of body density as determined by the relationship of BODY WEIGHT to BODY HEIGHT. BMI=weight (kg)/height squared (m2). BMI correlates with body fat (ADIPOSE TISSUE). Their relationship varies with age and gender. For adults, BMI falls into these categories: below 18.5 (underweight); 18.5-24.9 (normal); 25.0-29.9 (overweight); 30.0 and above (obese). (National Center for Health Statistics, Centers for Disease Control and Prevention)Angiotensin II: An octapeptide that is a potent but labile vasoconstrictor. It is produced from angiotensin I after the removal of two amino acids at the C-terminal by ANGIOTENSIN CONVERTING ENZYME. The amino acid in position 5 varies in different species. To block VASOCONSTRICTION and HYPERTENSION effect of angiotensin II, patients are often treated with ACE INHIBITORS or with ANGIOTENSIN II TYPE 1 RECEPTOR BLOCKERS.Angiotensin-Converting Enzyme Inhibitors: A class of drugs whose main indications are the treatment of hypertension and heart failure. They exert their hemodynamic effect mainly by inhibiting the renin-angiotensin system. They also modulate sympathetic nervous system activity and increase prostaglandin synthesis. They cause mainly vasodilation and mild natriuresis without affecting heart rate and contractility.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.Cardiac Output: The volume of BLOOD passing through the HEART per unit of time. It is usually expressed as liters (volume) per minute so as not to be confused with STROKE VOLUME (volume per beat).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.Renin-Angiotensin System: A BLOOD PRESSURE regulating system of interacting components that include RENIN; ANGIOTENSINOGEN; ANGIOTENSIN CONVERTING ENZYME; ANGIOTENSIN I; ANGIOTENSIN II; and angiotensinase. Renin, an enzyme produced in the kidney, acts on angiotensinogen, an alpha-2 globulin produced by the liver, forming ANGIOTENSIN I. Angiotensin-converting enzyme, contained in the lung, acts on angiotensin I in the plasma converting it to ANGIOTENSIN II, an extremely powerful vasoconstrictor. Angiotensin II causes contraction of the arteriolar and renal VASCULAR SMOOTH MUSCLE, leading to retention of salt and water in the KIDNEY and increased arterial blood pressure. In addition, angiotensin II stimulates the release of ALDOSTERONE from the ADRENAL CORTEX, which in turn also increases salt and water retention in the kidney. Angiotensin-converting enzyme also breaks down BRADYKININ, a powerful vasodilator and component of the KALLIKREIN-KININ SYSTEM.Pressoreceptors: Receptors in the vascular system, particularly the aorta and carotid sinus, which are sensitive to stretch of the vessel walls.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.Central Venous Pressure: The blood pressure in the central large VEINS of the body. It is distinguished from peripheral venous pressure which occurs in an extremity.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.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.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)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.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.Chromatography, High Pressure Liquid: Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.Rats, Sprague-Dawley: A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.Hydrochlorothiazide: A thiazide diuretic often considered the prototypical member of this class. It reduces the reabsorption of electrolytes from the renal tubules. This results in increased excretion of water and electrolytes, including sodium, potassium, chloride, and magnesium. It is used in the treatment of several disorders including edema, hypertension, diabetes insipidus, and hypoparathyroidism.Arteries: The vessels carrying blood away from the heart.Blood Flow Velocity: A value equal to the total volume flow divided by the cross-sectional area of the vascular bed.Dose-Response Relationship, Drug: The relationship between the dose of an administered drug and the response of the organism to the drug.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.Telemetry: Transmission of the readings of instruments to a remote location by means of wires, radio waves, or other means. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Aldosterone: A hormone secreted by the ADRENAL CORTEX that regulates electrolyte and water balance by increasing the renal retention of sodium and the excretion of potassium.Age Factors: Age as a constituent element or influence contributing to the production of a result. It may be applicable to the cause or the effect of a circumstance. It is used with human or animal concepts but should be differentiated from AGING, a physiological process, and TIME FACTORS which refers only to the passage of time.Cohort Studies: Studies in which subsets of a defined population are identified. These groups may or may not be exposed to factors hypothesized to influence the probability of the occurrence of a particular disease or other outcome. Cohorts are defined populations which, as a whole, are followed in an attempt to determine distinguishing subgroup characteristics.Cardiovascular Physiological Phenomena: Processes and properties of the CARDIOVASCULAR SYSTEM as a whole or of any of its parts.Pulmonary Wedge Pressure: The blood pressure as recorded after wedging a CATHETER in a small PULMONARY ARTERY; believed to reflect the PRESSURE in the pulmonary CAPILLARIES.Posture: The position or attitude of the body.Hypertrophy, Left Ventricular: Enlargement of the LEFT VENTRICLE of the heart. This increase in ventricular mass is attributed to sustained abnormal pressure or volume loads and is a contributor to cardiovascular morbidity and mortality.Sodium: A member of the alkali group of metals. It has the atomic symbol Na, atomic number 11, and atomic weight 23.Calibration: Determination, by measurement or comparison with a standard, of the correct value of each scale reading on a meter or other measuring instrument; or determination of the settings of a control device that correspond to particular values of voltage, current, frequency or other 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.Aorta: The main trunk of the systemic arteries.Obesity: A status with BODY WEIGHT that is grossly above the acceptable or desirable weight, usually due to accumulation of excess FATS in the body. The standards may vary with age, sex, genetic or cultural background. In the BODY MASS INDEX, a BMI greater than 30.0 kg/m2 is considered obese, and a BMI greater than 40.0 kg/m2 is considered morbidly obese (MORBID OBESITY).Hypertension, Renovascular: Hypertension due to RENAL ARTERY OBSTRUCTION or compression.African Continental Ancestry Group: Individuals whose ancestral origins are in the continent of Africa.Monitoring, Physiologic: The continuous measurement of physiological processes, blood pressure, heart rate, renal output, reflexes, respiration, etc., in a patient or experimental animal; includes pharmacologic monitoring, the measurement of administered drugs or their metabolites in the blood, tissues, or urine.Sodium Chloride: A ubiquitous sodium salt that is commonly used to season food.Autonomic Nervous System: The ENTERIC NERVOUS SYSTEM; PARASYMPATHETIC NERVOUS SYSTEM; and SYMPATHETIC NERVOUS SYSTEM taken together. Generally speaking, the autonomic nervous system regulates the internal environment during both peaceful activity and physical or emotional stress. Autonomic activity is controlled and integrated by the CENTRAL NERVOUS SYSTEM, especially the HYPOTHALAMUS and the SOLITARY NUCLEUS, which receive information relayed from VISCERAL AFFERENTS.Sex Factors: Maleness or femaleness as a constituent element or influence contributing to the production of a result. It may be applicable to the cause or effect of a circumstance. It is used with human or animal concepts but should be differentiated from SEX CHARACTERISTICS, anatomical or physiological manifestations of sex, and from SEX DISTRIBUTION, the number of males and females in given circumstances.Sex Determination Analysis: Validation of the SEX of an individual by inspection of the GONADS and/or by genetic tests.Blood Glucose: Glucose in blood.Captopril: A potent and specific inhibitor of PEPTIDYL-DIPEPTIDASE A. It blocks the conversion of ANGIOTENSIN I to ANGIOTENSIN II, a vasoconstrictor and important regulator of arterial blood pressure. Captopril acts to suppress the RENIN-ANGIOTENSIN SYSTEM and inhibits pressure responses to exogenous angiotensin.TetrazolesCross-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)Hypotension, Orthostatic: A significant drop in BLOOD PRESSURE after assuming a standing position. Orthostatic hypotension is a finding, and defined as a 20-mm Hg decrease in systolic pressure or a 10-mm Hg decrease in diastolic pressure 3 minutes after the person has risen from supine to standing. Symptoms generally include DIZZINESS, blurred vision, and SYNCOPE.Heart: The hollow, muscular organ that maintains the circulation of the blood.Aging: The gradual irreversible changes in structure and function of an organism that occur as a result of the passage of time.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.Atenolol: A cardioselective beta-1 adrenergic blocker possessing properties and potency similar to PROPRANOLOL, but without a negative inotropic effect.Vasoconstrictor Agents: Drugs used to cause constriction of the blood vessels.Amlodipine: A long-acting dihydropyridine calcium channel blocker. It is effective in the treatment of ANGINA PECTORIS and HYPERTENSION.Natriuresis: Sodium excretion by URINATION.Phenylephrine: An alpha-1 adrenergic agonist used as a mydriatic, nasal decongestant, and cardiotonic agent.Sensitivity and Specificity: Binary classification measures to assess test results. Sensitivity or recall rate is the proportion of true positives. Specificity is the probability of correctly determining the absence of a condition. (From Last, Dictionary of Epidemiology, 2d ed)Rats, Wistar: A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.Renal Circulation: The circulation of the BLOOD through the vessels of the KIDNEY.Vasodilation: The physiological widening of BLOOD VESSELS by relaxing the underlying VASCULAR SMOOTH MUSCLE.Albuminuria: The presence of albumin in the urine, an indicator of KIDNEY DISEASES.Vasoconstriction: The physiological narrowing of BLOOD VESSELS by contraction of the VASCULAR SMOOTH MUSCLE.Respiration: The act of breathing with the LUNGS, consisting of INHALATION, or the taking into the lungs of the ambient air, and of EXHALATION, or the expelling of the modified air which contains more CARBON DIOXIDE than the air taken in (Blakiston's Gould Medical Dictionary, 4th ed.). This does not include tissue respiration (= OXYGEN CONSUMPTION) or cell respiration (= CELL RESPIRATION).Diuretics: Agents that promote the excretion of urine through their effects on kidney function.Prevalence: The total number of cases of a given disease in a specified population at a designated time. It is differentiated from INCIDENCE, which refers to the number of new cases in the population at a given time.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.Prehypertension: Blood pressure levels that are between normotension and hypertension. Individuals with prehypertension are at a higher risk for developing cardiovascular diseases. Generally, prehypertension is defined as SYSTOLIC PRESSURE of 131-139 mm Hg and/or DIASTOLIC PRESSURE of 81-89 when the optimal is 120/80 mm Hg. For diabetics and other metabolism diseases the prehypertension is around 110-129/70-79 mm Hg.Reflex: An involuntary movement or exercise of function in a part, excited in response to a stimulus applied to the periphery and transmitted to the brain or spinal cord.Disease Models, Animal: Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.Osmotic Pressure: The pressure required to prevent the passage of solvent through a semipermeable membrane that separates a pure solvent from a solution of the solvent and solute or that separates different concentrations of a solution. It is proportional to the osmolality of the solution.Vasodilator Agents: Drugs used to cause dilation of the blood vessels.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.Glomerular Filtration Rate: The volume of water filtered out of plasma through glomerular capillary walls into Bowman's capsules per unit of time. It is considered to be equivalent to INULIN clearance.Angiotensin II Type 1 Receptor Blockers: Agents that antagonize ANGIOTENSIN II TYPE 1 RECEPTOR. Included are ANGIOTENSIN II analogs such as SARALASIN and biphenylimidazoles such as LOSARTAN. Some are used as ANTIHYPERTENSIVE AGENTS.Anesthesia: A state characterized by loss of feeling or sensation. This depression of nerve function is usually the result of pharmacologic action and is induced to allow performance of surgery or other painful procedures.Adrenergic beta-Antagonists: Drugs that bind to but do not activate beta-adrenergic receptors thereby blocking the actions of beta-adrenergic agonists. Adrenergic beta-antagonists are used for treatment of hypertension, cardiac arrhythmias, angina pectoris, glaucoma, migraine headaches, and anxiety.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.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.Desoxycorticosterone: A steroid metabolite that is the 11-deoxy derivative of CORTICOSTERONE and the 21-hydroxy derivative of PROGESTERONE.Enalapril: An angiotensin-converting enzyme inhibitor that is used to treat HYPERTENSION and HEART FAILURE.Cerebrovascular Circulation: The circulation of blood through the BLOOD VESSELS of the BRAIN.Brachial Artery: The continuation of the axillary artery; it branches into the radial and ulnar arteries.Manometry: Measurement of the pressure or tension of liquids or gases with a manometer.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.Catecholamines: A general class of ortho-dihydroxyphenylalkylamines derived from tyrosine.Pregnancy: The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.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)Random Allocation: A process involving chance used in therapeutic trials or other research endeavor for allocating experimental subjects, human or animal, between treatment and control groups, or among treatment groups. It may also apply to experiments on inanimate objects.JapanOxygen: An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.Losartan: An antagonist of ANGIOTENSIN TYPE 1 RECEPTOR with antihypertensive activity due to the reduced pressor effect of ANGIOTENSIN II.Peptidyl-Dipeptidase A: A peptidyl-dipeptidase that catalyzes the release of a C-terminal dipeptide, -Xaa-*-Xbb-Xcc, when neither Xaa nor Xbb is Pro. It is a Cl(-)-dependent, zinc glycoprotein that is generally membrane-bound and active at neutral pH. It may also have endopeptidase activity on some substrates. (From Enzyme Nomenclature, 1992) EC 3.4.15.1.Echocardiography: Ultrasonic recording of the size, motion, and composition of the heart and surrounding tissues. The standard approach is transthoracic.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.White Coat Hypertension: Phenomenon where BLOOD PRESSURE readings are elevated only when taken in clinical settings.European Continental Ancestry Group: Individuals whose ancestral origins are in the continent of Europe.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.Blood Volume: Volume of circulating BLOOD. It is the sum of the PLASMA VOLUME and ERYTHROCYTE VOLUME.Longitudinal Studies: Studies in which variables relating to an individual or group of individuals are assessed over a period of time.Lower Body Negative Pressure: External decompression applied to the lower body. It is used to study orthostatic intolerance and the effects of gravitation and acceleration, to produce simulated hemorrhage in physiologic research, to assess cardiovascular function, and to reduce abdominal stress during childbirth.Angiotensinogen: An alpha-globulin of about 453 amino acids, depending on the species. It is produced by the liver and secreted into blood circulation. Angiotensinogen is the inactive precursor of natural angiotensins. Upon successive enzyme cleavages, angiotensinogen yields angiotensin I, II, and III with amino acids numbered at 10, 8, and 7, respectively.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)Epinephrine: The active sympathomimetic hormone from the ADRENAL MEDULLA. It stimulates both the alpha- and beta- adrenergic systems, causes systemic VASOCONSTRICTION and gastrointestinal relaxation, stimulates the HEART, and dilates BRONCHI and cerebral vessels. It is used in ASTHMA and CARDIAC FAILURE and to delay absorption of local ANESTHETICS.Organ Size: The measurement of an organ in volume, mass, or heaviness.Cholesterol: The principal sterol of all higher animals, distributed in body tissues, especially the brain and spinal cord, and in animal fats and oils.Carbon Dioxide: A colorless, odorless gas that can be formed by the body and is necessary for the respiration cycle of plants and animals.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.Potassium: An element in the alkali group of metals with an atomic symbol K, atomic number 19, and atomic weight 39.10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the WATER-ELECTROLYTE BALANCE.Propranolol: A widely used non-cardioselective beta-adrenergic antagonist. Propranolol has been used for MYOCARDIAL INFARCTION; ARRHYTHMIA; ANGINA PECTORIS; HYPERTENSION; HYPERTHYROIDISM; MIGRAINE; PHEOCHROMOCYTOMA; and ANXIETY but adverse effects instigate replacement by newer drugs.Cardiomegaly: Enlargement of the HEART, usually indicated by a cardiothoracic ratio above 0.50. Heart enlargement may involve the right, the left, or both HEART VENTRICLES or HEART ATRIA. Cardiomegaly is a nonspecific symptom seen in patients with chronic systolic heart failure (HEART FAILURE) or several forms of CARDIOMYOPATHIES.Sex Characteristics: Those characteristics that distinguish one SEX from the other. The primary sex characteristics are the OVARIES and TESTES and their related hormones. Secondary sex characteristics are those which are masculine or feminine but not directly related to reproduction.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.Rats, Inbred Strains: Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations or by parent x offspring matings carried out with certain restrictions. This also includes animals with a long history of closed colony breeding.Calcium Channel Blockers: A class of drugs that act by selective inhibition of calcium influx through cellular membranes.Carotid Sinus: The dilated portion of the common carotid artery at its bifurcation into external and internal carotids. It contains baroreceptors which, when stimulated, cause slowing of the heart, vasodilatation, and a fall in blood pressure.Supine Position: The posture of an individual lying face up.Positive-Pressure Respiration: A method of mechanical ventilation in which pressure is maintained to increase the volume of gas remaining in the lungs at the end of expiration, thus reducing the shunting of blood through the lungs and improving gas exchange.Physical Exertion: Expenditure of energy during PHYSICAL ACTIVITY. Intensity of exertion may be measured by rate of OXYGEN CONSUMPTION; HEAT produced, or HEART RATE. Perceived exertion, a psychological measure of exertion, is included.Proteinuria: The presence of proteins in the urine, an indicator of KIDNEY DISEASES.Flow Injection Analysis: The analysis of a chemical substance by inserting a sample into a carrier stream of reagent using a sample injection valve that propels the sample downstream where mixing occurs in a coiled tube, then passes into a flow-through detector and a recorder or other data handling device.Metabolic Syndrome X: A cluster of metabolic risk factors for CARDIOVASCULAR DISEASES and TYPE 2 DIABETES MELLITUS. The major components of metabolic syndrome X include excess ABDOMINAL FAT; atherogenic DYSLIPIDEMIA; HYPERTENSION; HYPERGLYCEMIA; INSULIN RESISTANCE; a proinflammatory state; and a prothrombotic (THROMBOSIS) state. (from AHA/NHLBI/ADA Conference Proceedings, Circulation 2004; 109:551-556)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.Genotype: The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.Elasticity: Resistance and recovery from distortion of shape.Atrial Natriuretic Factor: A potent natriuretic and vasodilatory peptide or mixture of different-sized low molecular weight PEPTIDES derived from a common precursor and secreted mainly by the HEART ATRIUM. All these peptides share a sequence of about 20 AMINO ACIDS.Continuous Positive Airway Pressure: A technique of respiratory therapy, in either spontaneously breathing or mechanically ventilated patients, in which airway pressure is maintained above atmospheric pressure throughout the respiratory cycle by pressurization of the ventilatory circuit. (On-Line Medical Dictionary [Internet]. Newcastle upon Tyne(UK): The University Dept. of Medical Oncology: The CancerWEB Project; c1997-2003 [cited 2003 Apr 17]. Available from: http://cancerweb.ncl.ac.uk/omd/)Perindopril: An angiotensin-converting enzyme inhibitor. It is used in patients with hypertension and heart failure.Homeostasis: The processes whereby the internal environment of an organism tends to remain balanced and stable.Valsalva Maneuver: Forced expiratory effort against a closed GLOTTIS.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.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.Myocardium: The muscle tissue of the HEART. It is composed of striated, involuntary muscle cells (MYOCYTES, CARDIAC) connected to form the contractile pump to generate blood flow.Methods: A series of steps taken in order to conduct research.Diet: Regular course of eating and drinking adopted by a person or animal.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.NG-Nitroarginine Methyl Ester: A non-selective inhibitor of nitric oxide synthase. It has been used experimentally to induce hypertension.Electrolytes: Substances that dissociate into two or more ions, to some extent, in water. Solutions of electrolytes thus conduct an electric current and can be decomposed by it (ELECTROLYSIS). (Grant & Hackh's Chemical Dictionary, 5th ed)Blood Circulation: The movement of the BLOOD as it is pumped through the CARDIOVASCULAR SYSTEM.Anthropometry: The technique that deals with the measurement of the size, weight, and proportions of the human or other primate body.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.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.Clonidine: An imidazoline sympatholytic agent that stimulates ALPHA-2 ADRENERGIC RECEPTORS and central IMIDAZOLINE RECEPTORS. It is commonly used in the management of HYPERTENSION.Ventricular Function, Left: The hemodynamic and electrophysiological action of the left HEART VENTRICLE. Its measurement is an important aspect of the clinical evaluation of patients with heart disease to determine the effects of the disease on cardiac performance.Indicators and Reagents: Substances used for the detection, identification, analysis, etc. of chemical, biological, or pathologic processes or conditions. Indicators are substances that change in physical appearance, e.g., color, at or approaching the endpoint of a chemical titration, e.g., on the passage between acidity and alkalinity. Reagents are substances used for the detection or determination of another substance by chemical or microscopical means, especially analysis. Types of reagents are precipitants, solvents, oxidizers, reducers, fluxes, and colorimetric reagents. (From Grant & Hackh's Chemical Dictionary, 5th ed, p301, p499)Kidney Failure, Chronic: The end-stage of CHRONIC RENAL INSUFFICIENCY. It is characterized by the severe irreversible kidney damage (as measured by the level of PROTEINURIA) and the reduction in GLOMERULAR FILTRATION RATE to less than 15 ml per min (Kidney Foundation: Kidney Disease Outcome Quality Initiative, 2002). These patients generally require HEMODIALYSIS or KIDNEY TRANSPLANTATION.Hydralazine: A direct-acting vasodilator that is used as an antihypertensive agent.Cerebrospinal Fluid Pressure: Manometric pressure of the CEREBROSPINAL FLUID as measured by lumbar, cerebroventricular, or cisternal puncture. Within the cranial cavity it is called INTRACRANIAL PRESSURE.Heart Ventricles: The lower right and left chambers of the heart. The right ventricle pumps venous BLOOD into the LUNGS and the left ventricle pumps oxygenated blood into the systemic arterial circulation.Pregnancy Complications, Cardiovascular: The co-occurrence of pregnancy and a cardiovascular disease. The disease may precede or follow FERTILIZATION and it may or may not have a deleterious effect on the pregnant woman or FETUS.Receptor, Angiotensin, Type 1: An angiotensin receptor subtype that is expressed at high levels in a variety of adult tissues including the CARDIOVASCULAR SYSTEM, the KIDNEY, the ENDOCRINE SYSTEM and the NERVOUS SYSTEM. Activation of the type 1 angiotensin receptor causes VASOCONSTRICTION and sodium retention.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Propanolamines: AMINO ALCOHOLS containing the propanolamine (NH2CH2CHOHCH2) group and its derivatives.Sodium Chloride Symporter Inhibitors: Agents that inhibit SODIUM CHLORIDE SYMPORTERS. They act as DIURETICS. Excess use is associated with HYPOKALEMIA.Angiotensin Receptor Antagonists: Agents that antagonize ANGIOTENSIN RECEPTORS. Many drugs in this class specifically target the ANGIOTENSIN TYPE 1 RECEPTOR.Nifedipine: A potent vasodilator agent with calcium antagonistic action. It is a useful anti-anginal agent that also lowers blood pressure.Forearm: Part of the arm in humans and primates extending from the ELBOW to the WRIST.Aorta, Thoracic: The portion of the descending aorta proceeding from the arch of the aorta and extending to the DIAPHRAGM, eventually connecting to the ABDOMINAL AORTA.Oxygen Consumption: The rate at which oxygen is used by a tissue; microliters of oxygen STPD used per milligram of tissue per hour; the rate at which oxygen enters the blood from alveolar gas, equal in the steady state to the consumption of oxygen by tissue metabolism throughout the body. (Stedman, 25th ed, p346)