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Inotrope
An inotrope is an agent that alters the force or energy of muscular contractions. Negatively inotropic agents weaken the force of muscular contractions. Positively inotropic agents increase the strength of muscular contraction. The term ''inotropic state'' is most commonly used in reference to various drugs that affect the strength of contraction of heart muscle. However, it can also refer to pathological conditions. For example, enlarged heart muscle can increase inotropic state, whereas dead heart muscle can decrease it. Medical uses Both positive and negative inotropes are used in the management of various cardiovascular conditions. The choice of agent depends largely on specific pharmacological effects of individual agents with respect to the condition. One of the most important factors affecting inotropic state is the level of calcium in the cytoplasm of the muscle cell. Positive inotropes usually increase this level, while negative inotropes decrease it. However, not a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cardiogenic Shock
Cardiogenic shock (CS) is a medical emergency resulting from inadequate blood flow due to the dysfunction of the ventricles of the heart.Textbooks of Internal MedicinHarrison's Principles of Internal Medicine 16th Edition, The McGraw-Hill CompaniesCecil Textbook of Medicine by Lee Goldman, Dennis Ausiello, 22nd Edition (2003), W. B. Saunders CompanyThe Oxford Textbook of Medicine Edited by David A. Warrell, Timothy M. Cox and John D. Firth with Edward J. Benz, Fourth Edition (2003), Oxford University Press, Shock: An Overview PDF by Michael L. Cheatham, MD, Ernest F.J. Block, MD, Howard G. Smith, MD, John T. Promes, MD, Surgical Critical Care Service, Department of Surgical Education, |
Dobutamine
Dobutamine is a medication used in the treatment of cardiogenic shock (as a result of inadequate tissue perfusion) and severe heart failure. It may also be used in certain types of cardiac stress tests. It is given by IV only, as an injection into a vein or intraosseous as a continuous infusion. The amount of medication needs to be adjusted to the desired effect. Onset of effects is generally seen within 2 minutes. It has a half-life of two minutes. This drug is generally only administered short term, although it may be used for longer periods to relieve symptoms of heart failure in patients awaiting heart transplantation. Common side effects include a fast heart rate, an irregular heart beat, and inflammation at the site of injection. Use is not recommended in those with idiopathic hypertrophic subaortic stenosis. It primarily works by direct stimulation of β1 receptors, which increases the strength of the heart's contractions, leading to a positive ionotrophic effect. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adrenaline
Adrenaline, also known as epinephrine, is a hormone and medication which is involved in regulating visceral functions (e.g., respiration). It appears as a white microcrystalline granule. Adrenaline is normally produced by the adrenal glands and by a small number of neurons in the medulla oblongata. It plays an essential role in the fight-or-flight response by increasing blood flow to muscles, heart output by acting on the SA node, pupil dilation response, and blood sugar level. It does this by binding to alpha and beta receptors. It is found in many animals, including humans, and some single-celled organisms. It has also been isolated from the plant ''Scoparia dulcis'' found in Northern Vietnam. Medical uses As a medication, it is used to treat several conditions, including allergic reaction anaphylaxis, cardiac arrest, and superficial bleeding. Inhaled adrenaline may be used to improve the symptoms of croup. It may also be used for asthma when other treatments are not ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Levosimendan
Levosimendan (INN) is a calcium sensitizer used in the management of acutely decompensated congestive heart failure. It is marketed under the trade name Simdax ( Orion Corporation). Overall the drug has a two fold mechanism of action. It leads to greater ionotrophy by increasing the calcium sensitivity as it binds to Troponin and this results in a greater positive iontrophic force. Secondly, the drug is able to open ATP sensitive potassium channels in vascular smooth muscle cells, and the vascular dilatory effects of the drug lead to a decreased pre-load and afterload, putting less work on the heart. This drug is in the process of review by the FDA but has not been approved yet. Mechanism of action Levosimendan is a calcium sensitizer — it increases the sensitivity of the heart to calcium, thus increasing cardiac contractility without a rise in intracellular calcium. Levosimendan exerts its positive inotropic effect by increasing calcium sensitivity of myocytes by binding ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Action Potential
An action potential occurs when the membrane potential of a specific cell location rapidly rises and falls. This depolarization then causes adjacent locations to similarly depolarize. Action potentials occur in several types of animal cells, called excitable cells, which include neurons, muscle cells, and in some plant cells. Certain endocrine cells such as pancreatic beta cells, and certain cells of the anterior pituitary gland are also excitable cells. In neurons, action potentials play a central role in cell-cell communication by providing for—or with regard to saltatory conduction, assisting—the propagation of signals along the neuron's axon toward synaptic boutons situated at the ends of an axon; these signals can then connect with other neurons at synapses, or to motor cells or glands. In other types of cells, their main function is to activate intracellular processes. In muscle cells, for example, an action potential is the first step in the chain of event ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dopexamine
Dopexamine is a synthetic analogue of dopamine that is administered intravenously in hospitals to reduce exacerbations of heart failure and to treat heart failure following cardiac surgery. It is not used often, as more established drugs like epinephrine, dopamine, dobutamine, norepinephrine, and levosimendan work as well. It works by stimulating beta-2 adrenergic receptors and peripheral dopamine receptor D1 and dopamine receptor D2. It also inhibits the neuronal re-uptake of norepinephrine. The most common adverse effects include fast heart beats and nausea. It was discovered by scientists at Fisons, which licensed it to Ipsen in 1993, and Ipsen in turn licensed it to Élan in 1999. Ipsen licensed rights in North America and Japan to Circassia in 2008; the drug had never been approved in those countries. Dopexamine went off-patent in 2010. Medical use Dopexamine is used in hospitals as an inotropic agent to reduce exacerbations of heart failure and to trea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dopamine
Dopamine (DA, a contraction of 3,4-dihydroxyphenethylamine) is a neuromodulatory molecule that plays several important roles in cells. It is an organic chemical of the catecholamine and phenethylamine families. Dopamine constitutes about 80% of the catecholamine content in the brain. It is an amine synthesized by removing a carboxyl group from a molecule of its precursor chemical, L-DOPA, which is synthesized in the brain and kidneys. Dopamine is also synthesized in plants and most animals. In the brain, dopamine functions as a neurotransmitter—a chemical released by neurons (nerve cells) to send signals to other nerve cells. Neurotransmitters are synthesized in specific regions of the brain, but affect many regions systemically. The brain includes several distinct dopamine pathways, one of which plays a major role in the motivational component of reward-motivated behavior. The anticipation of most types of rewards increases the level of dopamine in the brain, and many ad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Catecholamine
A catecholamine (; abbreviated CA) is a monoamine neurotransmitter, an organic compound that has a catechol (benzene with two hydroxyl side groups next to each other) and a side-chain amine. Catechol can be either a free molecule or a substituent of a larger molecule, where it represents a 1,2-dihydroxybenzene group. Catecholamines are derived from the amino acid tyrosine, which is derived from dietary sources as well as synthesis from phenylalanine. Catecholamines are water-soluble and are 50% bound to plasma proteins in circulation. Included among catecholamines are epinephrine (adrenaline), norepinephrine (noradrenaline), and dopamine. Release of the hormones epinephrine and norepinephrine from the adrenal medulla of the adrenal glands is part of the fight-or-flight response. Tyrosine is created from phenylalanine by hydroxylation by the enzyme phenylalanine hydroxylase. Tyrosine is also ingested directly from dietary protein. Catecholamine-secreting cells u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcium
Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to its heavier homologues strontium and barium. It is the fifth most abundant element in Earth's crust, and the third most abundant metal, after iron and aluminium. The most common calcium compound on Earth is calcium carbonate, found in limestone and the fossilised remnants of early sea life; gypsum, anhydrite, fluorite, and apatite are also sources of calcium. The name derives from Latin ''calx'' " lime", which was obtained from heating limestone. Some calcium compounds were known to the ancients, though their chemistry was unknown until the seventeenth century. Pure calcium was isolated in 1808 via electrolysis of its oxide by Humphry Davy, who named the element. Calcium compounds are widely used in many industries: in food ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Berberine
Berberine is a quaternary ammonium salt from the protoberberine group of benzylisoquinoline alkaloids found in such plants as ''Berberis vulgaris'' (barberry), ''Berberis aristata'' (tree turmeric), ''Mahonia aquifolium'' (Oregon grape), ''Hydrastis canadensis'' (goldenseal), ''Xanthorhiza simplicissima'' (yellowroot), ''Phellodendron amurense'' (Amur cork tree), ''Coptis chinensis'' (Chinese goldthread), ''Tinospora cordifolia'', ''Argemone mexicana'' (prickly poppy), and ''Eschscholzia californica'' (Californian poppy). Berberine is usually found in the roots, rhizomes, stems, and bark. Due to its yellow color, ''Berberis'' species were used to dye wool, leather, and wood. Under ultraviolet light, berberine shows a strong yellow fluorescence, making it useful in histology for staining heparin in mast cells. As a natural dye, berberine has a color index of 75160. Research and adverse effects The safety of using berberine for any condition is not adequately defined by high-qua ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digoxin
Digoxin (better known as Digitalis), sold under the brand name Lanoxin among others, is a medication used to treat various heart conditions. Most frequently it is used for atrial fibrillation, atrial flutter, and heart failure. Digoxin is one of the oldest medications used in the field of cardiology. It works by increasing myocardial contractility, increasing stroke volume and blood pressure, reducing heart rate, and somewhat extending the time frame of the contraction. Digoxin is taken by mouth or by injection into a vein. Digoxin has a half life of approximately 36 hours given at average doses in patients with normal renal function. It is excreted mostly unchanged in the urine. Common side effects include breast enlargement with other side effects generally due to an excessive dose. These side effects may include loss of appetite, nausea, trouble seeing, confusion, and an irregular heartbeat. Greater care is required in older people and those with poor kidney function. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cardiomyopathy
Cardiomyopathy is a group of diseases that affect the heart muscle. Early on there may be few or no symptoms. As the disease worsens, shortness of breath, feeling tired, and swelling of the legs may occur, due to the onset of heart failure. An irregular heart beat and fainting may occur. Those affected are at an increased risk of sudden cardiac death. Types of cardiomyopathy include hypertrophic cardiomyopathy, dilated cardiomyopathy, restrictive cardiomyopathy, arrhythmogenic right ventricular dysplasia, and Takotsubo cardiomyopathy (broken heart syndrome). In hypertrophic cardiomyopathy the heart muscle enlarges and thickens. In dilated cardiomyopathy the ventricles enlarge and weaken. In restrictive cardiomyopathy the ventricle stiffens. In many cases, the cause cannot be determined. Hypertrophic cardiomyopathy is usually inherited, whereas dilated cardiomyopathy is inherited in about one third of cases. Dilated cardiomyopathy may also result from alcohol, h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
