Niacinamide: An important compound functioning as a component of the coenzyme NAD. Its primary significance is in the prevention and/or cure of blacktongue and PELLAGRA. Most animals cannot manufacture this compound in amounts sufficient to prevent nutritional deficiency and it therefore must be supplemented through dietary intake.Vasodilator Agents: Drugs used to cause dilation of the blood vessels.Glyburide: An antidiabetic sulfonylurea derivative with actions similar to those of chlorpropamide.Cromakalim: A potassium-channel opening vasodilator that has been investigated in the management of hypertension. It has also been tried in patients with asthma. (Martindale, The Extra Pharmacopoeia, 30th ed, p352)Pinacidil: A guanidine that opens POTASSIUM CHANNELS producing direct peripheral vasodilatation of the ARTERIOLES. It reduces BLOOD PRESSURE and peripheral resistance and produces fluid retention. (Martindale The Extra Pharmacopoeia, 31st ed)Benzopyrans: Compounds with a core of fused benzo-pyran rings.Anti-Arrhythmia Agents: Agents used for the treatment or prevention of cardiac arrhythmias. They may affect the polarization-repolarization phase of the action potential, its excitability or refractoriness, or impulse conduction or membrane responsiveness within cardiac fibers. Anti-arrhythmia agents are often classed into four main groups according to their mechanism of action: sodium channel blockade, beta-adrenergic blockade, repolarization prolongation, or calcium channel blockade.Potassium Channels: Cell membrane glycoproteins that are selectively permeable to potassium ions. At least eight major groups of K channels exist and they are made up of dozens of different subunits.Isosorbide Dinitrate: A vasodilator used in the treatment of ANGINA PECTORIS. Its actions are similar to NITROGLYCERIN but with a slower onset of action.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.KATP Channels: Heteromultimers of Kir6 channels (the pore portion) and sulfonylurea receptor (the regulatory portion) which affect function of the HEART; PANCREATIC BETA CELLS; and KIDNEY COLLECTING DUCTS. KATP channel blockers include GLIBENCLAMIDE and mitiglinide whereas openers include CROMAKALIM and minoxidil sulfate.Imino Pyranoses: Six-carbon pyranose sugars in which the OXYGEN is replaced by a NITROGEN atom.Decanoic Acids: 10-carbon saturated monocarboxylic acids.Hydroxy Acids: Organic compounds containing both the hydroxyl and carboxyl radicals.Methylene Blue: A compound consisting of dark green crystals or crystalline powder, having a bronze-like luster. Solutions in water or alcohol have a deep blue color. Methylene blue is used as a bacteriologic stain and as an indicator. It inhibits GUANYLATE CYCLASE, and has been used to treat cyanide poisoning and to lower levels of METHEMOGLOBIN.Guanidines: A family of iminourea derivatives. The parent compound has been isolated from mushrooms, corn germ, rice hulls, mussels, earthworms, and turnip juice. Derivatives may have antiviral and antifungal properties.Pyrroles: Azoles of one NITROGEN and two double bonds that have aromatic chemical properties.Ventricular Premature Complexes: A type of cardiac arrhythmia with premature contractions of the HEART VENTRICLES. It is characterized by the premature QRS complex on ECG that is of abnormal shape and great duration (generally >129 msec). It is the most common form of all cardiac arrhythmias. Premature ventricular complexes have no clinical significance except in concurrence with heart diseases.Angina Pectoris: The symptom of paroxysmal pain consequent to MYOCARDIAL ISCHEMIA usually of distinctive character, location and radiation. It is thought to be provoked by a transient stressful situation during which the oxygen requirements of the MYOCARDIUM exceed that supplied by the CORONARY CIRCULATION.Ischemic Preconditioning, Myocardial: Exposure of myocardial tissue to brief, repeated periods of vascular occlusion in order to render the myocardium resistant to the deleterious effects of ISCHEMIA or REPERFUSION. The period of pre-exposure and the number of times the tissue is exposed to ischemia and reperfusion vary, the average being 3 to 5 minutes.Picolines: A group of compounds that are monomethyl derivatives of pyridines. (From Dorland, 28th ed)Rectovaginal Fistula: An abnormal anatomical passage between the RECTUM and the VAGINA.Adenosine Triphosphate: An adenine nucleotide containing three phosphate groups esterified to the sugar moiety. In addition to its crucial roles in metabolism adenosine triphosphate is a neurotransmitter.Aminophylline: A drug combination that contains THEOPHYLLINE and ethylenediamine. It is more soluble in water than theophylline but has similar pharmacologic actions. It's most common use is in bronchial asthma, but it has been investigated for several other applications.Diltiazem: A benzothiazepine derivative with vasodilating action due to its antagonism of the actions of CALCIUM ion on membrane functions.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.Muscle Relaxation: That phase of a muscle twitch during which a muscle returns to a resting position.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)Oral Ulcer: A loss of mucous substance of the mouth showing local excavation of the surface, resulting from the sloughing of inflammatory necrotic tissue. It is the result of a variety of causes, e.g., denture irritation, aphthous stomatitis (STOMATITIS, APHTHOUS); NOMA; necrotizing gingivitis (GINGIVITIS, NECROTIZING ULCERATIVE); TOOTHBRUSHING; and various irritants. (From Jablonski, Dictionary of Dentistry, 1992, p842)Myocardial Ischemia: A disorder of cardiac function caused by insufficient blood flow to the muscle tissue of the heart. The decreased blood flow may be due to narrowing of the coronary arteries (CORONARY ARTERY DISEASE), to obstruction by a thrombus (CORONARY THROMBOSIS), or less commonly, to diffuse narrowing of arterioles and other small vessels within the heart. Severe interruption of the blood supply to the myocardial tissue may result in necrosis of cardiac muscle (MYOCARDIAL INFARCTION).Myocardial Infarction: NECROSIS of the MYOCARDIUM caused by an obstruction of the blood supply to the heart (CORONARY CIRCULATION).Diazoxide: A benzothiadiazine derivative that is a peripheral vasodilator used for hypertensive emergencies. It lacks diuretic effect, apparently because it lacks a sulfonamide group.Coronary Vessels: The veins and arteries of the HEART.Romano-Ward Syndrome: A form of long QT syndrome that is without congenital deafness. It is caused by mutation of the KCNQ1 gene which encodes a protein in the VOLTAGE-GATED POTASSIUM CHANNEL.Fissure in Ano: A painful linear ulcer at the margin of the anus. It appears as a crack or slit in the mucous membrane of the anus and is very painful and difficult to heal. (Dorland, 27th ed & Stedman, 25th ed)Myocardial Reperfusion: Generally, restoration of blood supply to heart tissue which is ischemic due to decrease in normal blood supply. The decrease may result from any source including atherosclerotic obstruction, narrowing of the artery, or surgical clamping. Reperfusion can be induced to treat ischemia. Methods include chemical dissolution of an occluding thrombus, administration of vasodilator drugs, angioplasty, catheterization, and artery bypass graft surgery. However, it is thought that reperfusion can itself further damage the ischemic tissue, causing MYOCARDIAL REPERFUSION INJURY.Verapamil: A calcium channel blocker that is a class IV anti-arrhythmia agent.Administration, Intravenous: Delivery of substances through VENIPUNCTURE into the VEINS.Myocardial Reperfusion Injury: Damage to the MYOCARDIUM resulting from MYOCARDIAL REPERFUSION (restoration of blood flow to ischemic areas of the HEART.) Reperfusion takes place when there is spontaneous thrombolysis, THROMBOLYTIC THERAPY, collateral flow from other coronary vascular beds, or reversal of vasospasm.Cardiac Complexes, Premature: A group of cardiac arrhythmias in which the cardiac contractions are not initiated at the SINOATRIAL NODE. They include both atrial and ventricular premature beats, and are also known as extra or ectopic heartbeats. Their frequency is increased in heart diseases.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.Sulfonylurea CompoundsCardiotonic Agents: Agents that have a strengthening effect on the heart or that can increase cardiac output. They may be CARDIAC GLYCOSIDES; SYMPATHOMIMETICS; or other drugs. They are used after MYOCARDIAL INFARCT; CARDIAC SURGICAL PROCEDURES; in SHOCK; or in congestive heart failure (HEART FAILURE).Hemodynamics: The movement and the forces involved in the movement of the blood through the CARDIOVASCULAR SYSTEM.Nicardipine: A potent calcium channel blockader with marked vasodilator action. It has antihypertensive properties and is effective in the treatment of angina and coronary spasms without showing cardiodepressant effects. It has also been used in the treatment of asthma and enhances the action of specific antineoplastic agents.Coronary Vasospasm: Spasm of the large- or medium-sized coronary arteries.Angina, Stable: Persistent and reproducible chest discomfort usually precipitated by a physical exertion that dissipates upon cessation of such an activity. The symptoms are manifestations of MYOCARDIAL ISCHEMIA.Injections, Intravenous: Injections made into a vein for therapeutic or experimental purposes.Carbonyl Cyanide m-Chlorophenyl Hydrazone: A proton ionophore. It is commonly used as an uncoupling agent and inhibitor of photosynthesis because of its effects on mitochondrial and chloroplast membranes.Tetraethylammonium CompoundsInfusions, Intravenous: The long-term (minutes to hours) administration of a fluid into the vein through venipuncture, either by letting the fluid flow by gravity or by pumping it.Diverticulum, Colon: A pouch or sac opening from the COLON.Dose-Response Relationship, Drug: The relationship between the dose of an administered drug and the response of the organism to the drug.Rubidium: An element that is an alkali metal. It has an atomic symbol Rb, atomic number 37, and atomic weight 85.47. It is used as a chemical reagent and in the manufacture of photoelectric cells.Oxadiazoles2-Chloroadenosine: 2-Chloroadenosine. A metabolically stable analog of adenosine which acts as an adenosine receptor agonist. The compound has a potent effect on the peripheral and central nervous system.Nifedipine: A potent vasodilator agent with calcium antagonistic action. It is a useful anti-anginal agent that also lowers blood pressure.Sulfonylurea Receptors: ATP-BINDING CASSETTE PROTEINS that are highly conserved and widely expressed in nature. They form an integral part of the ATP-sensitive potassium channel complex which has two intracellular nucleotide folds that bind to sulfonylureas and their analogs.Blood Pressure: PRESSURE of the BLOOD on the ARTERIES and other BLOOD VESSELS.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.Membrane Potentials: The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).Angioplasty, Balloon, Coronary: Dilation of an occluded coronary artery (or arteries) by means of a balloon catheter to restore myocardial blood supply.Coronary Circulation: The circulation of blood through the CORONARY VESSELS of the HEART.Rubidium Radioisotopes: Unstable isotopes of rubidium that decay or disintegrate emitting radiation. Rb atoms with atomic weights 79-84, and 86-95 are radioactive rubidium isotopes.Mitochondria, Heart: The mitochondria of the myocardium.Arrhythmias, Cardiac: Any disturbances of the normal rhythmic beating of the heart or MYOCARDIAL CONTRACTION. Cardiac arrhythmias can be classified by the abnormalities in HEART RATE, disorders of electrical impulse generation, or impulse conduction.Potassium Channels, Inwardly Rectifying: Potassium channels where the flow of K+ ions into the cell is greater than the outward flow.Calcium Channel Blockers: A class of drugs that act by selective inhibition of calcium influx through cellular membranes.Guinea Pigs: A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.Nitric Oxide Donors: A diverse group of agents, with unique chemical structures and biochemical requirements, which generate NITRIC OXIDE. These compounds have been used in the treatment of cardiovascular diseases and the management of acute myocardial infarction, acute and chronic congestive heart failure, and surgical control of blood pressure. (Adv Pharmacol 1995;34:361-81)PyransRadionuclide Ventriculography: Imaging of a ventricle of the heart after the injection of a radioactive contrast medium. The technique is less invasive than cardiac catheterization and is used to assess ventricular function.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.Methacholine Compounds: A group of compounds that are derivatives of beta-methylacetylcholine (methacholine).1-Deoxynojirimycin: An alpha-glucosidase inhibitor with antiviral action. Derivatives of deoxynojirimycin may have anti-HIV activity.Cyclic GMP: Guanosine cyclic 3',5'-(hydrogen phosphate). A guanine nucleotide containing one phosphate group which is esterified to the sugar moiety in both the 3'- and 5'-positions. It is a cellular regulatory agent and has been described as a second messenger. Its levels increase in response to a variety of hormones, including acetylcholine, insulin, and oxytocin and it has been found to activate specific protein kinases. (From Merck Index, 11th ed)Isoproterenol: Isopropyl analog of EPINEPHRINE; beta-sympathomimetic that acts on the heart, bronchi, skeletal muscle, alimentary tract, etc. It is used mainly as bronchodilator and heart stimulant.Mesenteric Arteries: Arteries which arise from the abdominal aorta and distribute to most of the intestines.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.Immersion: The placing of a body or a part thereof into a liquid.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.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.Heart Rate: The number of times the HEART VENTRICLES contract per unit of time, usually per minute.Adenoma, Islet Cell: A benign tumor of the pancreatic ISLET CELLS. Usually it involves the INSULIN-producing PANCREATIC BETA CELLS, as in INSULINOMA, resulting in HYPERINSULINISM.Potassium Chloride: A white crystal or crystalline powder used in BUFFERS; FERTILIZERS; and EXPLOSIVES. It can be used to replenish ELECTROLYTES and restore WATER-ELECTROLYTE BALANCE in treating HYPOKALEMIA.GTP Cyclohydrolase: (GTP cyclohydrolase I) or GTP 7,8-8,9-dihydrolase (pyrophosphate-forming) (GTP cyclohydrolase II). An enzyme group that hydrolyzes the imidazole ring of GTP, releasing carbon-8 as formate. Two C-N bonds are hydrolyzed and the pentase unit is isomerized. This is the first step in the synthesis of folic acid from GTP. EC (GTP cyclohydrolase I) and EC (GTP cyclohydrolase II).Monocrotaline: A pyrrolizidine alkaloid and a toxic plant constituent that poisons livestock and humans through the ingestion of contaminated grains and other foods. The alkaloid causes pulmonary artery hypertension, right ventricular hypertrophy, and pathological changes in the pulmonary vasculature. Significant attenuation of the cardiopulmonary changes are noted after oral magnesium treatment.Hypoglycemic Agents: Substances which lower blood glucose levels.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.Muscle, Smooth, Vascular: The nonstriated involuntary muscle tissue of blood vessels.Pyridines: Compounds with a six membered aromatic ring containing NITROGEN. The saturated version is PIPERIDINES.Purkinje Fibers: Modified cardiac muscle fibers composing the terminal portion of the heart conduction system.Electrophysiology: The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.Drug Administration Routes: The various ways of administering a drug or other chemical to a site in a patient or animal from where the chemical is absorbed into the blood and delivered to the target tissue.Hydroxybenzoates: Benzoate derivatives substituted by one or more hydroxy groups in any position on the benzene ring.Sarcolemma: The excitable plasma membrane of a muscle cell. (Glick, Glossary of Biochemistry and Molecular Biology, 1990)Potassium Channel Blockers: A class of drugs that act by inhibition of potassium efflux through cell membranes. Blockade of potassium channels prolongs the duration of ACTION POTENTIALS. They are used as ANTI-ARRHYTHMIA AGENTS and VASODILATOR AGENTS.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.Premedication: Preliminary administration of a drug preceding a diagnostic, therapeutic, or surgical procedure. The commonest types of premedication are antibiotics (ANTIBIOTIC PROPHYLAXIS) and anti-anxiety agents. It does not include PREANESTHETIC MEDICATION.Administration, Oral: The giving of drugs, chemicals, or other substances by mouth.Nitric Oxide Synthase Type III: A CALCIUM-dependent, constitutively-expressed form of nitric oxide synthase found primarily in ENDOTHELIAL CELLS.Rabbits: The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.Heart: The hollow, muscular organ that maintains the circulation of the blood.Nicorandil: A derivative of the NIACINAMIDE that is structurally combined with an organic nitrate. It is a potassium-channel opener that causes vasodilatation of arterioles and large coronary arteries. Its nitrate-like properties produce venous vasodilation through stimulation of guanylate cyclase.Aminoquinolines: Quinolines substituted in any position by one or more amino groups.Trachea: The cartilaginous and membranous tube descending from the larynx and branching into the right and left main bronchi.Cardiovascular Agents: Agents that affect the rate or intensity of cardiac contraction, blood vessel diameter, or blood volume.AcetophenonesMuscle, Smooth: Unstriated and unstriped muscle, one of the muscles of the internal organs, blood vessels, hair follicles, etc. Contractile elements are elongated, usually spindle-shaped cells with centrally located nuclei. Smooth muscle fibers are bound together into sheets or bundles by reticular fibers and frequently elastic nets are also abundant. (From Stedman, 25th ed)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.Guanylate Cyclase: An enzyme that catalyzes the conversion of GTP to 3',5'-cyclic GMP and pyrophosphate. It also acts on ITP and dGTP. (From Enzyme Nomenclature, 1992) EC 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.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.Cardiac Catheterization: Procedures in which placement of CARDIAC CATHETERS is performed for therapeutic or diagnostic procedures.Ureter: One of a pair of thick-walled tubes that transports urine from the KIDNEY PELVIS to the URINARY BLADDER.Acidosis: A pathologic condition of acid accumulation or depletion of base in the body. The two main types are RESPIRATORY ACIDOSIS and metabolic acidosis, due to metabolic acid build up.Receptors, Drug: Proteins that bind specific drugs with high affinity and trigger intracellular changes influencing the behavior of cells. Drug receptors are generally thought to be receptors for some endogenous substance not otherwise specified.Nephritis, Interstitial: Inflammation of the interstitial tissue of the kidney. This term is generally used for primary inflammation of KIDNEY TUBULES and/or surrounding interstitium. For primary inflammation of glomerular interstitium, see GLOMERULONEPHRITIS. Infiltration of the inflammatory cells into the interstitial compartment results in EDEMA, increased spaces between the tubules, and tubular renal dysfunction.Femoral Artery: The main artery of the thigh, a continuation of the external iliac artery.Prostaglandin Endoperoxides, Synthetic: Synthetic compounds that are analogs of the naturally occurring prostaglandin endoperoxides and that mimic their pharmacologic and physiologic activities. They are usually more stable than the naturally occurring compounds.Oxidative Stress: A disturbance in the prooxidant-antioxidant balance in favor of the former, leading to potential damage. Indicators of oxidative stress include damaged DNA bases, protein oxidation products, and lipid peroxidation products (Sies, Oxidative Stress, 1991, pxv-xvi).Collateral Circulation: Maintenance of blood flow to an organ despite obstruction of a principal vessel. Blood flow is maintained through small vessels.Nitrates: Inorganic or organic salts and esters of nitric acid. These compounds contain the NO3- radical.Long QT Syndrome: A condition that is characterized by episodes of fainting (SYNCOPE) and varying degree of ventricular arrhythmia as indicated by the prolonged QT interval. The inherited forms are caused by mutation of genes encoding cardiac ion channel proteins. The two major forms are ROMANO-WARD SYNDROME and JERVELL-LANGE NIELSEN SYNDROME.NG-Nitroarginine Methyl Ester: A non-selective inhibitor of nitric oxide synthase. It has been used experimentally to induce hypertension.Heart Failure: A heterogeneous condition in which the heart is unable to pump out sufficient blood to meet the metabolic need of the body. Heart failure can be caused by structural defects, functional abnormalities (VENTRICULAR DYSFUNCTION), or a sudden overload beyond its capacity. Chronic heart failure is more common than acute heart failure which results from sudden insult to cardiac function, such as MYOCARDIAL INFARCTION.Cyclic N-Oxides: Heterocyclic compounds in which an oxygen is attached to a cyclic nitrogen.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.Ventricular Remodeling: The geometric and structural changes that the HEART VENTRICLES undergo, usually following MYOCARDIAL INFARCTION. It comprises expansion of the infarct and dilatation of the healthy ventricle segments. While most prevalent in the left ventricle, it can also occur in the right ventricle.Swine: Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA).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.Drug Interactions: The action of a drug that may affect the activity, metabolism, or toxicity of another drug.Arteries: The vessels carrying blood away from the heart.Coronary Angiography: Radiography of the vascular system of the heart muscle after injection of a contrast medium.Coronary Stenosis: Narrowing or constriction of a coronary artery.Uncoupling Agents: Chemical agents that uncouple oxidation from phosphorylation in the metabolic cycle so that ATP synthesis does not occur. Included here are those IONOPHORES that disrupt electron transfer by short-circuiting the proton gradient across mitochondrial membranes.Tachycardia, Ventricular: An abnormally rapid ventricular rhythm usually in excess of 150 beats per minute. It is generated within the ventricle below the BUNDLE OF HIS, either as autonomic impulse formation or reentrant impulse conduction. Depending on the etiology, onset of ventricular tachycardia can be paroxysmal (sudden) or nonparoxysmal, its wide QRS complexes can be uniform or polymorphic, and the ventricular beating may be independent of the atrial beating (AV dissociation).Ion Channel Gating: The opening and closing of ion channels due to a stimulus. The stimulus can be a change in membrane potential (voltage-gated), drugs or chemical transmitters (ligand-gated), or a mechanical deformation. Gating is thought to involve conformational changes of the ion channel which alters selective permeability.Echocardiography: Ultrasonic recording of the size, motion, and composition of the heart and surrounding tissues. The standard approach is transthoracic.Anesthetics, Inhalation: Gases or volatile liquids that vary in the rate at which they induce anesthesia; potency; the degree of circulation, respiratory, or neuromuscular depression they produce; and analgesic effects. Inhalation anesthetics have advantages over intravenous agents in that the depth of anesthesia can be changed rapidly by altering the inhaled concentration. Because of their rapid elimination, any postoperative respiratory depression is of relatively short duration. (From AMA Drug Evaluations Annual, 1994, p173)Percutaneous Coronary Intervention: A family of percutaneous techniques that are used to manage CORONARY OCCLUSION, including standard balloon angioplasty (PERCUTANEOUS TRANSLUMINAL CORONARY ANGIOPLASTY), the placement of intracoronary STENTS, and atheroablative technologies (e.g., ATHERECTOMY; ENDARTERECTOMY; THROMBECTOMY; PERCUTANEOUS TRANSLUMINAL LASER ANGIOPLASTY). PTCA was the dominant form of PCI, before the widespread use of stenting.Vasodilation: The physiological widening of BLOOD VESSELS by relaxing the underlying VASCULAR SMOOTH MUSCLE.Action Potentials: Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli.Isoflurane: A stable, non-explosive inhalation anesthetic, relatively free from significant side effects.Chemistry, Pharmaceutical: Chemistry dealing with the composition and preparation of agents having PHARMACOLOGIC ACTIONS or diagnostic use.Heart Conduction System: An impulse-conducting system composed of modified cardiac muscle, having the power of spontaneous rhythmicity and conduction more highly developed than the rest of the heart.Reactive Oxygen Species: Molecules or ions formed by the incomplete one-electron reduction of oxygen. These reactive oxygen intermediates include SINGLET OXYGEN; SUPEROXIDES; PEROXIDES; HYDROXYL RADICAL; and HYPOCHLOROUS ACID. They contribute to the microbicidal activity of PHAGOCYTES, regulation of signal transduction and gene expression, and the oxidative damage to NUCLEIC ACIDS; PROTEINS; and LIPIDS.Ventricular Fibrillation: A potentially lethal cardiac arrhythmia that is characterized by uncoordinated extremely rapid firing of electrical impulses (400-600/min) in HEART VENTRICLES. Such asynchronous ventricular quivering or fibrillation prevents any effective cardiac output and results in unconsciousness (SYNCOPE). It is one of the major electrocardiographic patterns seen with CARDIAC ARREST.Myocardial Contraction: Contractile activity of the MYOCARDIUM.Fluorescence: The property of emitting radiation while being irradiated. The radiation emitted is usually of longer wavelength than that incident or absorbed, e.g., a substance can be irradiated with invisible radiation and emit visible light. X-ray fluorescence is used in diagnosis.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.Microcirculation: The circulation of the BLOOD through the MICROVASCULAR NETWORK.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.Regional Blood Flow: The flow of BLOOD through or around an organ or region of the body.Quaternary Ammonium Compounds: Derivatives of ammonium compounds, NH4+ Y-, in which all four of the hydrogens bonded to nitrogen have been replaced with hydrocarbyl groups. These are distinguished from IMINES which are RN=CR2.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.Human Umbilical Vein Endothelial Cells: Endothelial cells that line venous vessels of the UMBILICAL CORD.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Reperfusion Injury: Adverse functional, metabolic, or structural changes in ischemic tissues resulting from the restoration of blood flow to the tissue (REPERFUSION), including swelling; HEMORRHAGE; NECROSIS; and damage from FREE RADICALS. The most common instance is MYOCARDIAL REPERFUSION INJURY.Formaldehyde: A highly reactive aldehyde gas formed by oxidation or incomplete combustion of hydrocarbons. In solution, it has a wide range of uses: in the manufacture of resins and textiles, as a disinfectant, and as a laboratory fixative or preservative. Formaldehyde solution (formalin) is considered a hazardous compound, and its vapor toxic. (From Reynolds, Martindale The Extra Pharmacopoeia, 30th ed, p717)Diabetes Mellitus, Experimental: Diabetes mellitus induced experimentally by administration of various diabetogenic agents or by PANCREATECTOMY.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.Acute Disease: Disease having a short and relatively severe course.Carbachol: A slowly hydrolyzed CHOLINERGIC AGONIST that acts at both MUSCARINIC RECEPTORS and NICOTINIC RECEPTORS.Ion Channels: Gated, ion-selective glycoproteins that traverse membranes. The stimulus for ION CHANNEL GATING can be due to a variety of stimuli such as LIGANDS, a TRANSMEMBRANE POTENTIAL DIFFERENCE, mechanical deformation or through INTRACELLULAR SIGNALING PEPTIDES AND PROTEINS.Kidney Glomerulus: A cluster of convoluted capillaries beginning at each nephric tubule in the kidney and held together by connective tissue.Spin Labels: Molecules which contain an atom or a group of atoms exhibiting an unpaired electron spin that can be detected by electron spin resonance spectroscopy and can be bonded to another molecule. (McGraw-Hill Dictionary of Chemical and Technical Terms, 4th ed)Vasoconstrictor Agents: Drugs used to cause constriction of the blood vessels.Mice, Inbred ICRAngina, Unstable: Precordial pain at rest, which may precede a MYOCARDIAL INFARCTION.ATP-Binding Cassette Transporters: A family of MEMBRANE TRANSPORT PROTEINS that require ATP hydrolysis for the transport of substrates across membranes. The protein family derives its name from the ATP-binding domain found on the protein.Electrocardiography, Ambulatory: Method in which prolonged electrocardiographic recordings are made on a portable tape recorder (Holter-type system) or solid-state device ("real-time" system), while the patient undergoes normal daily activities. It is useful in the diagnosis and management of intermittent cardiac arrhythmias and transient myocardial ischemia.Cells, Cultured: Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.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.Drug Therapy, Combination: Therapy with two or more separate preparations given for a combined effect.Capillaries: The minute vessels that connect the arterioles and venules.Hypertension, Pulmonary: Increased VASCULAR RESISTANCE in the PULMONARY CIRCULATION, usually secondary to HEART DISEASES or LUNG DISEASES.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.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.Stroke Volume: The amount of BLOOD pumped out of the HEART per beat, not to be confused with cardiac output (volume/time). It is calculated as the difference between the end-diastolic volume and the end-systolic volume.Patch-Clamp Techniques: An electrophysiologic technique for studying cells, cell membranes, and occasionally isolated organelles. All patch-clamp methods rely on a very high-resistance seal between a micropipette and a membrane; the seal is usually attained by gentle suction. The four most common variants include on-cell patch, inside-out patch, outside-out patch, and whole-cell clamp. Patch-clamp methods are commonly used to voltage clamp, that is control the voltage across the membrane and measure current flow, but current-clamp methods, in which the current is controlled and the voltage is measured, are also used.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.Thrombolytic Therapy: Use of infusions of FIBRINOLYTIC AGENTS to destroy or dissolve thrombi in blood vessels or bypass grafts.Natriuretic Peptide, Brain: A PEPTIDE that is secreted by the BRAIN and the HEART ATRIA, stored mainly in cardiac ventricular MYOCARDIUM. It can cause NATRIURESIS; DIURESIS; VASODILATION; and inhibits secretion of RENIN and ALDOSTERONE. It improves heart function. It contains 32 AMINO ACIDS.NADPH Oxidase: A flavoprotein enzyme that catalyzes the univalent reduction of OXYGEN using NADPH as an electron donor to create SUPEROXIDE ANION. The enzyme is dependent on a variety of CYTOCHROMES. Defects in the production of superoxide ions by enzymes such as NADPH oxidase result in GRANULOMATOUS DISEASE, CHRONIC.Antioxidants: Naturally occurring or synthetic substances that inhibit or retard the oxidation of a substance to which it is added. They counteract the harmful and damaging effects of oxidation in animal tissues.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.Aorta: The main trunk of the systemic arteries.Coronary Artery Disease: Pathological processes of CORONARY ARTERIES that may derive from a congenital abnormality, atherosclerotic, or non-atherosclerotic cause.Hospitalization: The confinement of a patient in a hospital.Calcium: A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.Blotting, Western: Identification of proteins or peptides that have been electrophoretically separated by blot transferring from the electrophoresis gel to strips of nitrocellulose paper, followed by labeling with antibody probes.Drug Administration Schedule: Time schedule for administration of a drug in order to achieve optimum effectiveness and convenience.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.Calcium Channels: Voltage-dependent cell membrane glycoproteins selectively permeable to calcium ions. They are categorized as L-, T-, N-, P-, Q-, and R-types based on the activation and inactivation kinetics, ion specificity, and sensitivity to drugs and toxins. The L- and T-types are present throughout the cardiovascular and central nervous systems and the N-, P-, Q-, & R-types are located in neuronal tissue.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.Apoptosis: One of the mechanisms by which CELL DEATH occurs (compare with NECROSIS and AUTOPHAGOCYTOSIS). Apoptosis is the mechanism responsible for the physiological deletion of cells and appears to be intrinsically programmed. It is characterized by distinctive morphologic changes in the nucleus and cytoplasm, chromatin cleavage at regularly spaced sites, and the endonucleolytic cleavage of genomic DNA; (DNA FRAGMENTATION); at internucleosomal sites. This mode of cell death serves as a balance to mitosis in regulating the size of animal tissues and in mediating pathologic processes associated with tumor growth.Prognosis: A prediction of the probable outcome of a disease based on a individual's condition and the usual course of the disease as seen in similar situations.Glucose: A primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. It is used therapeutically in fluid and nutrient replacement.Mitochondria: Semiautonomous, self-reproducing organelles that occur in the cytoplasm of all cells of most, but not all, eukaryotes. Each mitochondrion is surrounded by a double limiting membrane. The inner membrane is highly invaginated, and its projections are called cristae. Mitochondria are the sites of the reactions of oxidative phosphorylation, which result in the formation of ATP. They contain distinctive RIBOSOMES, transfer RNAs (RNA, TRANSFER); AMINO ACYL T RNA SYNTHETASES; and elongation and termination factors. Mitochondria depend upon genes within the nucleus of the cells in which they reside for many essential messenger RNAs (RNA, MESSENGER). Mitochondria are believed to have arisen from aerobic bacteria that established a symbiotic relationship with primitive protoeukaryotes. (King & Stansfield, A Dictionary of Genetics, 4th ed)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.

Cardioprotection by opening of the K(ATP) channel in unstable angina. Is this a clinical manifestation of myocardial preconditioning? Results of a randomized study with nicorandil. CESAR 2 investigation. Clinical European studies in angina and revascularization. (1/236)

AIMS: To assess the anti-ischaemic and anti-arrhythmic effects and overall safety of nicorandil, an ATP sensitive potassium (K+) channel opener, with 'cardioprotective' effects, in patients with unstable angina. METHODS: In a multicentre, randomized, double-blind, parallel-group, placebo-controlled study, oral nicorandil 20 mg twice daily or a matching placebo was administered for a minimum of 48 h to patients admitted with unstable angina. Treatment was standardized to include, where tolerated, oral aspirin, a beta-blocker and diltiazem. Continuous Holter ECG monitoring was performed for 48 h to assess the frequency and duration of transient myocardial ischaemia and any tachyarrhythmia, as the predefined end-points of the study. A pain chart recorded the incidence and severity of chest pain throughout the study period. Patients with myocardial infarction identified retrospectively from troponin-T analysis were excluded. RESULTS: Two hundred and forty-five patients were recruited into the study. Forty-three patients were excluded with an index diagnosis of myocardial infarction, two were not randomized and 12 had unsatisfactory tape data. In the remaining 188 patients, six out of 89 patients (6.7%) on nicorandil experienced an arrhythmia, compared with 17 out of 99 patients (17.2%) on placebo (P=0.04). Three nicorandil patients experienced three runs of non-sustained ventricular tachycardia compared to 31 runs in 10 patients on placebo (P=0.087 patients; P<0.0001 runs). Three nicorandil patients had four runs of supraventricular tachycardia, compared to 15 runs in nine patients on placebo (P=0.14 patients; P=0.017 runs). Eleven (12.4%) patients on nicorandil had 37 episodes of transient myocardial ischaemia (mostly silent) compared with 74 episodes in 21 (21.2%) patients on placebo (P=0.12 patients; P=0.0028 episodes). In the overall safety analysis, which included all patients who received at least one dose of study medication, there were no significant differences in the rates of myocardial infarction or death between the nicorandil or placebo-treated groups. CONCLUSIONS: Nicorandil, added to aggressive anti-anginal treatment for unstable angina, reduces transient myocardial ischaemia, non-sustained ventricular, and supraventricular arrhythmia compared to placebo. The anti-arrhythmic activity with nicorandil is probably a secondary effect resulting from its anti-ischaemic action and we suggest that this may be related to its effect on the ATP sensitive potassium channel causing pharmacological preconditioning.  (+info)

Intravenous nicorandil can preserve microvascular integrity and myocardial viability in patients with reperfused anterior wall myocardial infarction. (2/236)

OBJECTIVES: We assessed whether the intravenous administration of nicorandil, an adenosine triphosphate (ATP)-sensitive K+ channel opener, exerts beneficial effect on microvascular function and functional and clinical outcomes in patients with acute myocardial infarction (AMI). BACKGROUND: Experimental studies documented that ATP-sensitive K+ channel opener exerts cardioprotection after prolonged ischemia. METHODS: We randomly divided 81 patients with a first anterior AMI into two groups, nicorandil (n = 40) and control groups (n = 41). All patients received successful coronary angioplasty within 12 h after the symptom onset and underwent myocardial contrast echcardiography (MCE) with the intracoronary injection of sonicated microbubbles. In the nicorandil group, we injected 4 mg of nicorandil followed by the infusion at 6 mg/h for 24 h and by oral nicorandil (15 mg/day). RESULTS: The improvement in regional left ventricular function, wall motion score and regional wall motion was significantly better in the nicorandil group then in the control group. Intractable congestive heart failure, malignant ventricular arrhythmia and pericardial effusion were more frequently found in the control group than in the nicorandil group (15% vs. 37%, 5% vs. 20% and 8% vs. 37%, p < 0.05, respectively). The frequency of sizable MCE no reflow phenomenon was significantly lower in the nicorandil group than in the control group (15% vs. 33%, p < 0.05). CONCLUSIONS: Intravenous nicorandil in conjunction with coronary angioplasty is associated with better functional and clinical outcomes compared to angioplasty alone in patients with an anterior AMI. Myocardial contrast echocardiography findings imply that an improvement in microvascular function with nicorandil may be attributable to this better outcome.  (+info)

Effects of nicorandil on experimentally induced gastric ulcers in rats: a possible role of K(ATP) channels. (3/236)

The anti-ulcer effects of nicorandil [N-(2-hydroxyethyl)nicotinamide nitrate ester] were examined on water-immersion plus restraint stress-induced and aspirin-induced gastric ulcers in rats, compared with those of cimetidine. Nicorandil (3 and 10 mg/kg) given orally to rats dose-dependently inhibited the development of acid-related damage (water-immersion- and aspirin-induced gastric lesions) in the models. Cimetidine (50 mg/kg, p.o.) also had anti-ulcer effects in the same models. However, in the presence of glibenclamide (20 mg/kg, i.v.), an antagonist of K(ATP) channels, nicorandil did not inhibit the formation of gastric lesions. Nicorandil (10 mg/kg) given intraduodenally (i.d.), like cimetidine (50 mg/kg), significantly reduced the volume of the gastric content, total acidity and total acid output in the pylorus ligation model. Glibenclamide reversed the changes caused by i.d. nicorandil. I.v. infusion of nicorandil (20 microg/kg per min) significantly increased gastric mucosal blood flow, without affecting blood pressure and heart rate, but the increase in the blood flow was not observed after i.v. treatment with glibenclamide (20 mg/kg). These results indicate that nicorandil administered orally to rats produces the anti-ulcer effect by reducing the aggressive factors and by enhancing the defensive process in the mucosa through its K(ATP)-channel-opening property.  (+info)

Effects of nicorandil on aortic input impedance: a comparative study with nitroglycerin. (4/236)

A study of aortic input impedance was performed to evaluate the effects of nicorandil on the systemic circulation, and the effects were compared with those of nitroglycerin. Sixteen patients with coronary artery disease were divided into 2 age-matched groups. Aortic input impedance was obtained from Fourier analysis of aortic pressure and flow signals at baseline conditions, after intravenous administration of either 4 mg (Group 1) or 8 mg (Group 2) nicorandil, and 20 min after 0.3 mg sublingual nitroglycerin. In Group 1, the first harmonic impedance modulus (Z1, 304+/-140 dyne x s x cm(-5)) and the average of the first to third harmonics (Z1-3, 207+/-99 dyne x s x cm(-5)), indices of wave reflection, significantly decreased (24.4% (p<0.05) and 24.7% (p<0.01), respectively) after nicorandil, and 41.3% (p<0.01) and 33.9% (p<0.01) after nitroglycerin. The effects between the 2 vasodilators were not significantly different. In Group 2, Z1 and Z1-3 (275+/-138 and 196+/-93 dyne x s x cm(-5), respectively) also decreased after administration of nicorandil (28.4% (p<0.01) and 35.9% (p<0.01), respectively), and after administration of nitroglycerin (23.9% (p<0.01) and 28.7% (p<0.01), respectively), without any significant difference between the 2 drugs. Characteristic impedance and total peripheral resistance (R) in both groups remained unchanged except for R after 8 mg nicorandil (from 1830+/-415 to 1433+/-428 dyne x s x cm(-5); p<0.01). Like nitroglycerin, both doses of nicorandil reduced wave reflection. The reduction in R after 8 mg nicorandil is related to decreased tone in the resistance arteries, probably due to potassium channel opener effects.  (+info)

Effects of nicorandil as compared to mixtures of sodium nitroprusside and levcromakalim in isolated rat aorta. (5/236)

1. The contribution of the relaxant mechanisms of nicorandil (NIC) were analysed by comparing its effects with those of sodium nitroprusside (SNP), levcromakalim (LEM) and mixtures (1:10, 1:30 and 1:100) of SNP:LEM in isolated endothelium-denuded rat aorta. 2. In rings precontracted with KCl (25 mM), the relative inhibitory potency of the soluble guanylate cyclase inhibitor ODQ and the K(ATP) channel inhibitor glibenclamide (GLI) on SNP:LEM mixtures showed a good correlation with the relative proportion of SNP and LEM in the mixtures. Furthermore, the degree of the inhibition by ODQ and GLI of the effects of the 1:30 SNP:LEM mixture varied as a function of the relative potency of SNP and LEM in KCl-, noradrenaline- (NA) or NA plus nifedipine-treated arteries. 3. The inhibitory effects of ODQ, GLI and ODQ plus GLI on NIC-induced relaxation was similar to that for the 1:30 SNP:LEM mixture in NA plus nifedipine-contracted arteries, but the inhibition of GLI or ODQ plus GLI was smaller in KCl-contracted arteries. 4. In conclusion, the relative importance of activation of the cyclic GMP pathway and K(ATP) channel opening in mixtures of SNP and LEM could be predicted by the proportion of the drugs in the mixtures and by the relative potency of SNP vs LEM in different experimental conditions. Furthermore, the present results suggest that besides these two mechanisms, a third ODQ- and GLI-insensitive mechanism, possibly involving Ca2+ channel blockade, also participates in the relaxant effects of NIC in KCl-induced contractions.  (+info)

Nonischemic ST-segment elevation induced by negative inotropic agents. (6/236)

The present study investigated whether regional ventricular dyskinesia (ie, systolic bulging) is a direct cause of ST-segment elevation in canine hearts in vivo. Regional ventricular dyskinesia was induced in 33 anesthetized open-chest dogs by injection of negative inotropic agents into the left anterior descending coronary artery (LAD) without disruption of coronary blood flow. Regional myocardial contraction was assessed in terms of the percent systolic shortening (%SS) and percent systolic bulging (%bulging), which were measured using ultrasonic crystals. The ST-segment elevation of the LAD-perfused area was measured with a unipolar electrode. Lidocaine, a sodium channel blocker, nicorandil, a potassium channel opener, propranolol, a beta-adrenergic blocker, or verapamil, a calcium channel blocker, was administered by intracoronary injection during maximal vasodilation induced by adenosine. All drugs induced dose-dependent ST-segment elevation in association with a parallel reduction in %SS and a parallel increase in %bulging. The absence of myocardial ischemia was confirmed by the absence of NADH fluorescence. It was concluded that regional ventricular dyskinesia had an important role in ST-segment elevation not associated with myocardial ischemia.  (+info)

Nicorandil abolished repolarisation alternans in a patient with idiopathic long QT syndrome. (7/236)

A 23 year old woman with idiopathic long QT syndrome had repeated syncopal attacks associated with torsades de pointes. T wave alternans (TWA) was recorded and the QT interval was abnormally prolonged during treadmill exercise test. Monophasic action potential (MAP) alternans also appeared after an abrupt shortening of the cycle length in electrophysiological study. After intravenous administration of nicorandil 6 mg, both TWA and MAP alternans disappeared.  (+info)

Three minute, but not one minute, ischemia and nicorandil have a preconditioning effect in patients with coronary artery disease. (8/236)

OBJECTIVES: This study focused on 1) the determination of the optimal preconditioning (PC) duration, and 2) the protective effect of nicorandil (NC), a hybrid nitrate with a KATP channel opening effect, during a percutaneous transluminal coronary angioplasty (PTCA) model in humans. BACKGROUND: The ischemic PC effect is induced in 180 s ischemia, but not in 120 s ischemia in rabbit hearts. However, the duration of ischemia that induces PC effect and the role of the KATP channel in the PC effect in humans are still unclear. METHODS: Forty-six patients with stable angina were randomly allocated to four groups: the duration of the first inflation as PC ischemia was 60 s in the PC60 group (n = 12), and 180 s in the PC180 group (n = 12). In the other groups, NC (80 microg/kg) was intravenously given for 1 min in the NC group (n = 12), and isosorbide dinitrate (ISDN) (40 microg/kg) was given in the ISDN group (n = 10). Five minutes after first inflation or drug administration, a second inflation was conducted for 120 s in each group. In the ECG, the lead with the largest shift in ST segment (deltaST max), and the sum of elevated ST levels in all leads (sigmaST) were determined. RESULTS: In the PC60 group, no significant difference was observed in either deltaST max or sigmaST between the first and second inflation. However, the second inflation in the PC180 group showed significantly lower levels of deltaST max and sigmaST compared with those of the first inflation. In the NC group, both deltaST max and sigmaST measured at 30 s and 60 s after balloon inflation were significantly lower than those of the first inflation in the PC60 and PC180 control groups. In the ISDN group, no significant difference was observed in deltaST max or sigmaST. CONCLUSION: In human PTCA models, a PC effect is observed in 180 s ischemia, but not in 60 s ischemia. A pharmacological PC effect is induced by NC, a KATP channel opener with a nitrate-like effect but not ISDN. This suggests that the opening of KATP channels plays an important role in the protecting effect of NC.  (+info)

  • Nicorandil, an ATP sensitive potassium-channel opener, may reduce the incidence of microvascular dysfunction after percutaneous coronary intervention (PCI) by dilating coronary resistance vessels. (
  • The goal of the trial was to evaluate treatment with nicorandil, a hybrid adenosine triphosphate-sensitive potassium channel (K ATP ) activator and vascular smooth muscle relaxant, in patients undergoing percutaneous coronary intervention (PCI). (
  • The goal of these two trials was to evaluate the effect of the human atrial natriuretic peptide (hANP) carperitide and nicorandil, compared with control, among patients with ST elevation myocardial infarction (MI) treated with percutaneous coronary intervention (PCI). (
  • drop out rate 10%, an event rate of the primary end point for two years 50%, a risk reduction rate brought by nicorandil 60%, a statistical power 80% and two-sided significant level 0.05. (
  • The number of attacks during the pretreatment period, 3.6 +/- 0.4 per day, became significantly reduced to 0.7 +/- 0.2 per day during nicorandil therapy (P less than 0.001) and significantly increased to 1.3 +/- 0.3 per day after withdrawal of the drug (P less than 0.05). (
  • In 17 patients with continuous ECG monitoring, the frequency of occurrence of ST-segment elevation was 8.6 +/- 2.7 per day during the preobservation period, significantly decreased to 0.4 +/- 0.2 per day during nicorandil therapy (P less than 0.01), and significantly increased to 1.9 +/- 0.7 per day after withdrawal of the drug (P less than 0.05). (
  • To study the role of pre-operative oral nicorandil in decreasing reperfusion cardiac injury in patients subjected to cardiac valve surgery. (
  • Pre-operative oral nicorandil expressively decreased myocardial reperfusion damage during open heart valve operations, this evidenced by the decrease in the postoperative use of inotropic drugs, considerable reduction of postoperative elevation of cardiac enzymes and inflammatory cytokines with no reported complications. (
  • here in our study we tried to explore the effect of pre-operative oral nicorandil on myocardial ischemia/reperfusion injury and record its effect in patient subjected to open heart valve surgery. (
  • Oral nicorandil 15 to 60mg did not consistently affect the systolic blood pressure response to exercise, although a decrease in preload is still evident (33%) and a transient increase in exercise heart rate may be apparent 30 minutes post dose (20 to 30mg). (
  • Design and patients The effect of oral nicorandil (15 to 60 mg daily for four weeks) on premature ventricular contractions was investigated in 20 patients (11 female, nine male, mean (SD) age 63 (17) years) who underwent 24 hour ambulatory ECG. (
  • Therefore, by combining these two vasodilator mechanisms, nicorandil represents a novel type of compound for use in the treatment of angina pectoris. (
  • In summary, clinical experience thus far indicates that nicorandil, with its novel combination of two distinct vasodilator mechanisms, offers an effective alternative to established vasodilator therapy with conventional nitrates and calcium antagonists in the long term treatment of stable angina pectoris. (
  • Effect of intravenous nicorandil and preexisting angina pectoris on short- and long-term outcomes in patients with a first ST-segment elevation acute myocardial infarction. (
  • It's even weirder that he wants to switch atenolol for nicorandil, when most cardiologist actually prescribe combination of nicorandil and atenolol for angina pectoris patients. (
  • His cardiologist too switched him from atenolol to Nicorandil, but he at least explained to us why he was doing this - dad's cardiac function tests results weren't as good as when he first started atenolol and he switched him to Nicorandil to prevent his angina pectoris from worsening in the future. (
  • Nicorandil is used to treat chronic stable angina pectoris. (
  • The effect of nicorandil, a new coronary vasodilator, was evaluated in 32 patients with variant angina pectoris in a single-blind trial. (
  • The results demonstrate the effectiveness of nicorandil in the treatment of variant angina pectoris. (
  • Nicorandil, marketed in the UK as Ikorel, is a powerful potassium-channel activator to treat angina pectoris (severe chest pains), and a recent study suggests it is a very effective one. (
  • Nicorandil and long-acting nitrates are vasodilatory drugs used commonly in the management of chronic stable angina pectoris. (
  • Currently nicorandil, a potassium channel opener is being frequently used for the prevention and long-term treatment of angina pectoris. (
  • In comparative trials involving a total of 84 patients who received nicorandil, the incidence of headache was similar to that produced by isosorbide mononitrate and isosorbide dinitrate. (
  • The incidence of adverse events was not modified when nicorandil was given in combination with a beta-blocker, a calcium antagonist, or both agents. (
  • In comparative studies of nicorandil versus beta-blockers, calcium antagonists, or nitrates, the overall incidence of adverse events was no different between the two treatment groups, although the safety profile differed according to the drug category. (
  • The purpose of this study is to prospectively investigate whether nicorandil is effective in reducing the incidence of cardiovascular events in patients with CAD on hemodialysis. (
  • Therefore, investigators prospectively examine whether nicorandil is effective in reducing the incidence of cardiovascular events in patients with CAD on hemodialysis. (
  • The incidence of post-PCI SCF (cTFC >20 frames) was also significantly lower in patients treated with nicorandil (4.4% vs. 17.8%, p (
  • However, there was no reduction in incidence of major adverse cardiac events (MACE) at 12 months with nicorandil therapy. (
  • The results of this study suggest that administration of intravenous nicorandil prior to PCI may reduce the incidence of SCF in both the ACS and non-ACS populations. (
  • The incidence of CIN also did not differ between the nicorandil and control groups (6.8% vs. 6.6%, p=0.794). (
  • Prophylactic intravenous infusion of nicorandil did not decrease the incidence of CIN in patients with renal dysfunction undergoing coronary angiography. (
  • Nicorandil is potentially effective to prevent cardiovascular events in patients with coronary artery disease (CAD) receiving hemodialysis. (
  • Main outcome measures: Costs were for use of hospital resources (for cardiovascular, cerebrovascular, and gastrointestinal reasons), nicorandil, and care after hospital discharge. (
  • This study delivers important new insight in the molecular pathways that may contribute to thebeneficial effects of nicorandil in the cardiovascular system. (
  • While there is some evidence to suggest a modest reduction in cardiovascular events among patients with stable angina treated with nicorandil compared to placebo, this prognostic benefit has yet to be proven conclusively. (
  • Nicorandil (Ikorel), indicated for the prevention and treatment of angina, is associated with a risk of gastrointestinal ulceration, including perianal ulceration, according to a recent safety update from the MHRA. (
  • The manufacturer of nicorandil ( Ikorel ® ) has written to healthcare professionals advising of new restrictions to the licensed indication and additional contraindications and warnings. (
  • The haemodynamic effects of nicorandil reach a peak within 1 to 2 minutes of intravenous administration or 30 to 60 minutes after a single oral dose (20 to 40 mg) and persist for up to 8 hours (40 to 60mg). (
  • Headache, mostly of mild to moderate intensity was the most commonly reported adverse event, occurring in one-third of patients receiving the recommended therapeutic regimen of nicorandil 10 to 20mg twice daily. (
  • He had been receiving 20mg twice-daily nicorandil for the previous 2 years. (
  • Nicorandil enhances the effect of endothelial nitric oxide under hypoxia-reoxygenation: role of the KATP channel. (
  • Therefore, the changes in p120 were observed in the DRG and spinal cord of rats following the intraperitoneal injection of nicorandil, a KATP agonist. (
  • Extracellular potassium dependent negative dromotropic action of nicorandil in guinea pig myocardium. (
  • Although the antiarrhythmic action of nicorandil is drawing an increasing attention, dromotropic effect of this agent is unclear. (
  • Fingerprint Dive into the research topics of 'Extracellular potassium dependent negative dromotropic action of nicorandil in guinea pig myocardium. (
  • The duration of action of Nicorandil is 2 to 3 minutes, its effects on hemodynamics are minimal. (
  • Cultured HUVECs were exposed to cyclic strain in the presence of nicorandil, ET−1 expression was examined by reverse transcriptase− polymerase chain reaction and ELISA. (
  • Nicorandil prevents endothelial dysfunction due to antioxidative effects via normalisation of NADPH oxidase and nitric oxide synthase in streptozotocin diabetic rats. (
  • The effect of aminoguanidine, nicorandil and their combination against oxidative stress in streptozotocin (STZ) - induced diabetes mellitus was assessed in rats by determining changes in blood glucose level, superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH), malondialdehyde (MDA) and nitric oxide (NO) in healthy and experimentally induced diabetic rats. (
  • Treatments of the diabetic rats with aminoguanidine, nicorandil and their combination led to improvement of the abnormalities in SOD, CAT, GSH, MDA, NO and also the histhopathological abnormalities of kidney and liver. (
  • Study of influence of nicorandil on hypoglycemic action of glibenclamide in alloxan induced diabetic rats. (
  • Feasibility and safety of intracoronary nicorandil infusion as a novel hyperemic agent for fractional flow reserve measurements. (
  • A total of 140 STEMI patients were divided into three groups according to different patterns of administration: sequential nicorandil group, intracoronary nicorandil group and control group. (
  • All antiarrhythmic agents, including digitalis, were discontinued at least one week before any nicorandil was given. (
  • The duration of hyperemia after IV nicorandil was variable (6-570 s, mean 89 ± 98 s). (
  • In conclusions, the results of the present study suggest that IV nicorandil can achieve maximal hyperemia easily and rapidly, providing an acceptable diagnostic performance for FFR assessment. (
  • Yet, nicorandil is effective in cases where nitrates, such as nitroglycerine, are not effective. (
  • Both nicorandil and long-acting nitrates exert anti-angina properties via activation of nitric oxide (NO) signalling pathways, triggering vascular smooth muscle cell relaxation. (
  • Nicorandil has additional actions as an arterial K+ ATP channel agonist, resulting in more "balanced" arterial and venous vasodilatation than nitrates. (
  • Although calcium-channel antagonists are the drugs of choice for the treatment of angina resulting from coronary artery spasm, vasospastic angina can also be successfully treated with both nicorandil and nitrates. (
  • 7 However, long-acting nitrates are effective in only ~50 % of patients with microvascular angina 8 as, unlike nicorandil, they have little effect on small resistance vessels. (
  • This article provides a focused update on the use of nicorandil and long-acting nitrates for the treatment of stable angina. (
  • The objective of the present study was to investigate the effectiveness of intravenous (IV) nicorandil infusion for fractional flow reserve (FFR) measurement. (
  • Nicorandil infusion during inter-hospital transfer of patients with acute coronary syndrome - What can we do in a rural area of Japan? (
  • Nagayoshi Y, Kai Y, Yumoto S, Sakaguchi K, Shudo C, Takino S, Hashiyama M, Kawano H, Kuroda Y, Ogawa H. Nicorandil infusion during inter-hospital transfer of patients with acute coronary syndrome - What can we do in a rural area of Japan? (
  • For these reasons, the authors have been trying a nicorandil infusion protocol during inter-hospital transfer. (
  • Adjunctive nicorandil infusion protocol was performed if EMS took ACS patients to the non-PCI-capable hospital or the patients directly presented to the non-PCI-capable hospital. (
  • Between April 2011 and February 2013, 12 patients with ACS underwent adjunctive nicorandil infusion during inter-hospital transfer. (
  • Chest discomforts were reduced by nicorandil infusion in all seven patients. (
  • The dispersion of ventricular effective refractory period (VERP), longitudinal and transverse ventricular conduction velocities (thetaL and thetaT, respectively), and wavelength [lambda = VERP x theta(L or T)] were studied in Langendorff-perfused left ventricular epicardium in 20 rabbits during infusion of incremental doses of levcromakalim or nicorandil. (
  • Nicorandil is a vasodilatory drug used to treat angina. (
  • Nicorandil is a vasodilatory drug, which is contraindicated in patients with cardiogenic shock, right ventricular infarction, left ventricular failure with low filling pressure and hypotension. (
  • The results of an open prospective study that evaluated the long-term clinical safety of nicorandil are presented. (
  • From these results it can be concluded that aminoguanidine, nicorandil and their combination have the ability to attenuate oxidative stress induced by streptozotocin. (
  • In addition, the limited data available indicate that nicorandil may be effective in patients with unstable and variant angina who are refractory to therapy with conventional antianginal agents, a potentially important area for further study. (
  • Patients: Patients with angina fulfilling the entry criteria for the IONA trial Interventions: In one arm of the trial nicorandil was added to existing antianginal treatment and compared with existing treatment alone. (
  • Results Nicorandil reduced the frequency of premature ventricular contractions by 75% in five patients in group 2, but was not effective in any patient in group 1. (
  • There are two case reports which described the efficacy of nicorandil on ventricular arrhythmias in patients with the idiopathic long QT syndrome. (
  • We studied 20 patients (nine men and 11 women) aged 19 to 91 years (mean (SD) age 63 (17) years) with frequent premature ventricular contractions (table 1 ), defined as more than 1000 premature contractions per 24 hours before the start of nicorandil treatment. (
  • Likewise, the co-primary endpoint of left ventricular ejection fraction (LVEF) was increased 5.1% with carperitide compared with control, but there was no difference between nicorandil and control (p = NS). (
  • The primary endpoint of infarct size as assessed by area under the curve of creatine kinase (CK) was 14.7% lower with carperitide compared with control (p = 0.016), but there was no difference between nicorandil and control (p = NS). (
  • Nicorandil is now recommended for the treatment of stable angina in patients whose angina is inadequately controlled by first line treatments or who have a contraindication or intolerance to first line treatments. (
  • Updated advice on use of nicorandil as second-line treatment for stable angina - some ulcers may progress to complications unless treatment is stopped. (
  • Nicorandil ameliorated hypertensive renal injury without lowering blood pressure in spontaneously hypertensive rats. (
  • Nicorandil improves glomerular injury in rats with mesangioproliferative glomerulonephritis via inhibition of proproliferative and profibrotic growth factors. (
  • It was demonstrated that nicorandil administration could relieve mechanical pain experienced following SMIR in rats, and decrease the expression of p120 in the DRG and spinal cord. (