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Topic: Cardiac action potential

Ads by Google Related Topics action potential action philosophy cardiac arrhythmias advanced cardiac life support Cardiac pacemaker cardiac output Cardiac action potential cardiac muscle cardiac tamponade Cardiac pump cardiac stress test cardiac surgery cardiac catheterization cardiac failure      Study Outline Cardiac muscle is the muscle of the heart. Increasing the frequency of action potentials in a muscle fiber increases the mechanical response (tension or shortening), up to the level of maximal tetanic tension. Whether there is an accompanying change in muscle length depends upon the external forces acting on the muscle. http://www.mhhe.com/biosci/ap/vander/student/olc/chap11outline.html   (1438 words)      BioMedical Engineering OnLine Full text Dispersion of cardiac action potential duration and the initiation of ... Block of an action potential occurs if there is insufficient Na current to support a propagating wavefront [27]; when Na channels have not recovered from inactivation, then a propagating wave blocks and dissipates [28]. Faber GM, Rudy Y: Action potential and contractility changes in Na+ (i) overloaded cardiac myocytes: A simulation study. channel conductance on susceptibility to re-entry investigated in the present study, it does highlight the potential importance of this channel for the mechanisms of re-entry. http://www.biomedical-engineering-online.com/content/4/1/11   (5569 words)      Molecular dissection of cardiac repolarization by in vivo Kv4.3 gene transfer -- Hoppe et al. 105 (8): 1077 -- Journal ... Adenovirus-mediated expression of a voltage-gated potassium channel in vitro (rat cardiac myocytes) and in vivo (rat liver). New approaches to antiarrhythmic therapy; emerging therapeutic applications of the cell biology of cardiac arrhythmias substantially changed the action potential waveform of acutely dissected guinea pig myocytes in an I http://www.jci.org/cgi/content/full/105/8/1077   (5098 words)      Influence of IV Haloperidol on Ventricular Repolarization and Monophasic Action Potential Duration in Anesthetized Dogs ... Suessbrich, H, Schonherr, R, Heinemann, SH, et al The inhibitory effect of the antipsychotic drug haloperidol on HERG potassium channels expressed in Xenopus oocytes. Woosley, RL, Chen, Y, Freiman, JP, et al Mechanism of the cardiotoxic actions of terfenadine. Abbreviations: ANOVA = analysis of variance; APD = action potential http://www.chestjournal.org/cgi/content/full/125/5/1821   (3572 words)      KChAP: a novel chaperone for specific K+ channels key to repolarization of the cardiac action potential. Focus on ... MiRP1 forms IKr potassium channels with HERG and is associated with cardiac arrhythmia. channels key to repolarization of the cardiac action potential. Focus on "KChAP as a chaperone for specific K+ channels" -- Abriel et al. http://ajpcell.physiology.org/cgi/content/full/278/5/C863   (1107 words)      A Subset of Highly Effective Propafenone-Type Multidrug Resistance Modulators Lacks Effects on Cardiac Action Potential ... A and B, original traces of transmembrane action potentials (A) and their corresponding first derivatives (B) recorded in rat papillary muscles stimulated at 2 Hz. the effects of antiarrhythmic drugs on cardiac Na channels strength of the carbonyl group did not reestablish cardiac side http://www.jpet.org/cgi/content/full/307/2/589   (4359 words)      Human Physiology (IPHY 3430), University of Colorado at Boulder Most of our muscle mass is skeletal muscle. Define and give the physiological significance (how or why it is important) for the following terms: Which landmarks within the sarcomere change when the muscle fiber contracts? http://www.colorado.edu/epob/epob1220lynch/08muscle.html   (1830 words)      Regulation of action potential duration under acute heat stress by IK,ATP and IK1 in fish cardiac myocytes -- Paajanen ... cardiac myocytes, but it is likely that the nucleotide-binding channels in cardiac muscle from cold-acclimated goldfish: characterization and altered response to ATP. ATP-sensitive potassium channels: a review of their cardioprotective pharmacology. http://ajpregu.physiology.org/cgi/content/full/286/2/R405   (5111 words)      Pharmacologic Characterization of BMS-191095, a Mitochondrial KATP Opener with No Peripheral Vasodilator or Cardiac ... Pharmacologic Characterization of BMS-191095, a Mitochondrial KATP Opener with No Peripheral Vasodilator or Cardiac Action Potential Shortening Activity -- Grover et al. http://jpet.aspetjournals.org/cgi/reprint/297/3/1184   (32 words)      A Subset of Highly Effective Propafenone-type MDR- Modulators Lacks Effects on Cardiac Action Potential and Mechanical ... A Subset of Highly Effective Propafenone-type MDR- Modulators Lacks Effects on Cardiac Action Potential and Mechanical Twitch Parameters of Rat Papillary Muscles -- Schmid et al., 10.1124/jpet.103.052993 -- Journal of Pharmacology And Experimental Therapeutics http://jpet.aspetjournals.org/cgi/reprint/jpet.103.052993v1   (34 words)      Human Embryonic Stem Cells Develop Into Multiple Types of Cardiac Myocytes: Action Potential Characterization -- He et ... which are quite distinct from neonatal and adult cardiac muscle. of human cardiac myocytes for basic research, pharmacological cardiac myocytes including a positive inotropic response to http://circres.ahajournals.org/cgi/content/full/93/1/32   (5131 words)      Inositol 1,4,5-Trisphosphate Directs Ca2+ Flow between Mitochondria and the Endoplasmic/Sarcoplasmic Reticulum: A Role ... The figure is representative of five separate experiments. Cardiomyocytes were isolated from 2- to 3-d neonatal rats (Puceat et al. Thus, our results provide the first evidence that in http://www.molbiolcell.org/cgi/content/full/11/5/1845   (7819 words)      SIMPLE EXPERIMENTS TO UNDERSTAND THE IONIC ORIGINS AND CHARACTERISTICS OF THE VENTRICULAR CARDIAC ACTION POTENTIAL -- ... potential is due to the opening of the channels responsible Our general approach can be extended to other cardiac tissues to study the ionic basis of the action potential. http://advan.physiology.org/cgi/content/full/26/3/185   (2469 words)      Effect of niacinamide on cardiac output, cardiac excitability and membrane action potential of single cardiac muscle ... of the dog heart and on the action potentials of individual This drug increases respiratory and circulatory action chiefly The actions of niacinamide on cardiac output and cardiac excitability http://ajplegacy.physiology.org/cgi/content/abstract/196/4/735   (135 words)      Contribution of a swelling-activated chloride current to changes in the cardiac action potential -- Vandenberg et al. ... Contribution of a swelling-activated chloride current to changes in the cardiac action potential -- Vandenberg et al. Cardiac Ionic Currents and Acute Ischemia: From Channels to Arrhythmias Contribution of a swelling-activated chloride current to changes in the cardiac action potential http://ajpcell.physiology.org/cgi/content/abstract/273/2/C541   (544 words)      Cardiac action potential - Wikipedia, the free encyclopedia Phase 1 of the action potential is due to closure of the fast Na channels. This phase of the action potential is associated with diastole of the chamber of the heart. During phase 3 of the action potential, the K http://www.wikipedia.org/wiki/Cardiac_action_potential   (1098 words)      Spontaneous Miniature Hyperpolarizations Affect Threshold for Action Potential Generation in Mudpuppy Cardiac Neurons ... All experiments were performed on parasympathetic neurons dissociated from mudpuppy (Necturus maculosus) cardiac ganglia. SK channels did contribute to HAP generation in the mudpuppy cardiac Galanin-induced hyperpolarization and decreased excitability of neurones in mudpuppy cardiac ganglia. http://jn.physiology.org/cgi/content/full/88/3/1119   (6141 words)      Dofetilide - Wikipedia, the free encyclopedia It is this selective action on accessory pathways that makes dofetilide effective in the treatment of atrial fibrillation and flutter. Due to the pro-arrhythmic potential of dofetilide, it is only available by prescription by physicians who have undergone specific training in the risks of treatment with dofetilide. Based on the results of the Danish Investigations of Arrhythmias and Mortality on Dofetilide (DIAMOND) study, dofetilide does not effect mortality in the treatment of patients post-myocardial infarction with left ventricular dysfunction. http://www.wikipedia.org/wiki/Dofetilide   (664 words)      T wave alternans after sotalol: evidence for increased sensitivity to sotalol after conversion from atrial fibrillation ... No cardiac rhythm monitoring was present, but physical T wave "memory": possible causal relationship to stress-induced changes in cardiac ion channels? beats from phase 2 or phase 3 of the action potential. http://www.heartjnl.com/cgi/content/full/80/3/303   (2127 words)      qca2c The L-type channels are not responsible for the rapid initial phase. The L-type channels are responsible for the rapid initial phase of the action potential in cardiac myocyts. Rather, they are responsible for the plateau phase of the action potential. http://www.md.huji.ac.il/mirror/netpharm/qca2c.htm   (99 words)      Generation of an Action potential in cardiac cells The time during the upstroke is done slower so one can visualize the rapid influx of Na ions. Generation of an Action potential in cardiac cells This applet shows the generation of the AP for a cardiac cell. http://arrhythmia.hofstra.edu/java/cardiac/apcardiac.html   (38 words)      ELECTRICAL ACTIVATION OF MYOCARDIAL CELLS TREATMENT: Slow down the conduction through one pathway or the other. Cardiac muscle cells have prolonged refractory periods, to prevent tetany of cardiac muscle. of the cardiac action potential during phase 0. http://www.mednote.co.kr/PHYSIOLOGYBLUE/EKG.htm   (1456 words)      In the cardiac action potential This is important since tetany of the heart muscle would not allow effective pumping. The muscle twitch is of almost the same duration as the action potential, and since the refractory period extends beyond the end of the AP, the muscle cannot readily be tetanised. In the cardiac action potential, sodium channel opening is followed by inactivation. http://www.mona.uwi.edu/fpas/courses/physiology/muscles/Cardiac_action_potential.htm   (308 words)      Cardiac Action Potential ADAM Rapid spread of depolarization through the heart initiates contraction (similar to skeletal muscle) Sympathetic - innervates the SA and AV nodes and cardiac muscle fibers. Both sympathetic and parasympathetic nerve fibers travel from the medulla to the heart. http://www.accd.edu/pac/science/hopper/Biol2402/Unit2/02CVCS4R.html   (849 words)      Action potential of the myocardial cell Influx of Na+ from the extracellular fluid into the  cardiac cell leads to a positive feedback cycle that initiates the rising phase of  the AP (phase O) by opening voltage-regulated Na+ channels.  Contraction of cardiac muscle is triggered by action potential that sweep across  the muscle cell membranes.  The induction of phase O of the action potential is produced by the sudden  dramatic rise in the membrane permeability to Na ; resulting from the opening  of the membrane Na channels. http://www.perfusion.com.au/CCP/Physiology/Action%20potential%20of%20the%20myocardial%20cell.htm   (346 words)      Phases of the cardiac action potential The upstroke of the cardiac action potential in atrial and ventricular muscle and His-Purkinje fibers is due to the sudden increase in membrane conductance to Na+. The cardiac transmembrane potential consists of five phases: Under normal conditions, the membrane potential of atrial and ventricular muscle cells remains steady throughout diastole. http://www.cyberecg.com/CyberECG/ECGKb/ECGKB_eng/Enc00074.html   (256 words)      Electrotonic Cell-Cell Interactions in Cardiac Tissue: Effects on Action Potential Propagation and Repolarization -- ... on the dispersion of repolarization in cardiac tissue. Electrotonic Cell-Cell Interactions in Cardiac Tissue: Effects on Action Potential Propagation and Repolarization -- RUDY 1047 (1): 308 -- Annals of the New York Academy of Sciences Electrotonic Cell-Cell Interactions in Cardiac Tissue: Effects on Action Potential Propagation and Repolarization http://www.annalsnyas.org/cgi/content/abstract/1047/1/308   (157 words)      Action Alert - Potential Cardiac Effects of Disaster Additionally, patients already hospitalized for cardiac reasons should be monitored closely to ensure that their situations do not escalate in acuity due to the stresses associated with this type of tragedy. guarded eye towards the potential for inceased presentations of coronary patients and have staff prepared to deal with this situation. Action Alert - Potential Cardiac Effects of Disaster http://www.aameda.org/Specialtygroups/ActionAlerts/cardio91101.html   (233 words)      Cardiac Action Potential ADAM After depolarization, the cardiac myofibrils in contractile cells slide over each other resulting in muscle contraction. After repolarization (movement of K+ out of the cell) these cells relax. • Calcium influx produces the rapidly rising phase of the action potential (depolarization), which results in the reversal of membrane potential from negative to positive inside the cell. http://www.accd.edu/pac/science/hopper/Biol2402/Unit2/02CVAP5R.html   (725 words)      Relation of human cardiac action potential duration to the interval between beats: implications for the validity of ... Fourteen patients undergoing routine cardiac catheterisation were paced at Correlation of repolarization of ventricular monophasic action potential with ECG in the murine heart Relation of human cardiac action potential duration to the interval between beats: implications for the validity of rate corrected QT interval (QTc) -- Seed et al. http://heart.bmjjournals.com/cgi/content/abstract/57/1/32   (453 words)      Cardiac Action Potential Like all other excitable tissues, cardiac muscle is refractory to re-stimulation during the action potential. But as the action potential of cardiac muscle lasts almost as long as the contraction itself, the refractory period is almost as long as the contraction period - 0.25 to 0.3 secs (in the ventricles) Apart from the normal fast sodium channels (the same as for skeletal and nerve tissue), cardiac muscle contains slow calcium/sodium channels that are slow to close and let both calcium and sodium ions through. http://www.biotech.um.edu.mt/home_pages/chris/Basic%20Physiology/Basichtml/Heart3.htm   (147 words)      Cardiovascular Physiology (page 1) The cardiac action potential is much longer than that of skeletal muscle, and during this time the myocardial cell is unresponsive to further excitation. The myocardium consists of muscle cells which can contract spontaneously, also pacemaker and conducting cells, which have a specialised function. The relationship between electrical and mechanical events in the cardiac cycle is summarised in Figure 1. http://www.nda.ox.ac.uk/wfsa/html/u10/u1002_01.htm   (756 words)      Components of the cardiac action potential -- Hoshiko and Sperelakis 203 (2): 258 -- AJP - Legacy Components of the cardiac action potential -- Hoshiko and Sperelakis 203 (2): 258 -- AJP - Legacy potentials of frog ventricular strips under conditions of impaired Two components have been observed in the intracellular action http://ajplegacy.physiology.org/cgi/content/abstract/203/2/258   (155 words)      The Cardiovascular System, The Heart: Intrinsic Conduction System and Cardiac Action Potential State the voltage-gated channels responsible for the following stages of the action potential in cardiac contractile cells. The Cardiovascular System, The Heart: Intrinsic Conduction System and Cardiac Action Potential Name the three channels essential for generating an action potential. http://w3.tvi.edu/~mdanley/Bio238/Study%20Sheets/ICS.html   (165 words)      Effects of tissue geometry on initiation of a cardiac action potential -- Joyner et al. 256 (2): 391 -- AJP - Heart and ... Effects of tissue geometry on initiation of a cardiac action potential Effects of tissue geometry on initiation of a cardiac action potential -- Joyner et al. ventricular muscle cells to compare the effects of a decrease in cardiac http://ajpheart.physiology.org/cgi/content/abstract/256/2/H391   (353 words)      Two Components of the Cardiac Action Potential: I. Voltage-time course and the effect of acetylcholine on atrial and ... Extracellular Discontinuities in Cardiac Muscle : Evidence for Capillary Effects on the Action Potential Foot potential upstroke can be explained in terms of the relative Two Components of the Cardiac Action Potential: I. Voltage-time course and the effect of acetylcholine on atrial and nodal cells of the rabbit heart -- de Carvalho et al. http://www.jgp.org/cgi/content/abstract/54/5/607   (391 words)      A HERG current sustains a cardiac-type action potential in neuroblastoma S cells. The action potential depolarization phase was sustained by a TTX-sensitive Na(+) current, while the first repolarizing episode was produced by the scanty delayed rectifier potassium current (I(KDR)) expressed in 21S cells. A HERG current sustains a cardiac-type action potential in neuroblastoma S cells.From the adrenergic SH-SY5Y human neuroblastoma clone, we isolated a subclone (21S) endowed with a glial-oriented phenotype. The bulk of repolarization, including the after-hyperpolarization, was sustained by the human eag related (HERG) potassium current (I(HERG)) that also governs V(REST) in 21S cells. http://www.pdg.cnb.uam.es/UniPub/iHOP/gp/9853954.html   (173 words)      Modifications of the hemodynamic consequences of theophylline intoxication with landiolol in halothane-anesthetized ... in the treatment of hypertension, effort angina, and cardiac Effects of ONO-1101, a novel beta-antagonist, on action potential and membrane currents in cardiac muscle. depression, which is attributed to their long duration of action. http://www.cja-jca.org/cgi/content/full/47/3/265   (1810 words)      Effects of high extracellular [K+] and adrenaline on force development, relaxation and membrane potential in cardiac ... Effects of high extracellular [K+] and adrenaline on force development, relaxation and membrane potential in cardiac muscle from freshwater turtle and rainbow trout duration of the action potential, but did not affect the depolarisation, Force development, energy state and ATP production of cardiac muscle from turtles and trout during normoxia and severe hypoxia http://jeb.biologists.org/cgi/content/abstract/204/2/261   (363 words)      FitzHugh-Nagumo Simplified Cardiac Action Potential Model, 1961 The model was modified by Aliev and Panfilov to better approximate cardiac action potential properties. The number of equations is reduced to two: a cubic equation representing the fast variable (u) and liniar equation for the slow variable (vv). This model is part of the stable CESE distribution. http://cese.sourceforge.net/models/repository/FitzHughNagumoModel_1961.html   (102 words)      Oxford Cardiac Electrophysiology Group: Home The purpose of our group is to incorporate kinetic properties of molecular and cellular mechanism of cardiac activity into cellular and multicellular mathematical models of the heart. The Oxford Cardiac Electrophysiology Group is led by Prof. http://noble.physiol.ox.ac.uk   (36 words)      IngentaConnect Action Potential Prolongation in Cardiac Myocytes of Old Rats is ... IngentaConnect Action Potential Prolongation in Cardiac Myocytes of Old Rats is... Action Potential Prolongation in Cardiac Myocytes of Old Rats is an Adaptation to Sustain Youthful Intracellular Ca Regulation. Action Potential Prolongation in Cardiac Myocytes of Old Rats is an Adaptation to Sustain Youthful Intracellular Ca Regulation http://www.ingentaconnect.com/content/ap/mc/2002/00000034/00000006/art02004   (606 words)      Studies of the cardiac-like action potential in crayfish giant axons induced by platinized tungsten metal electrodes -- ... typically occurs within 10 min of the start of action potential elongation. Studies of the cardiac-like action potential in crayfish giant axons induced by platinized tungsten metal electrodes -- Orr and Lieberman 128 (1): 1 -- Journal of Experimental Biology a crayfish giant axon, causes the development of cardiac-like action http://jeb.biologists.org/cgi/content/abstract/128/1/1   (289 words)      Time course and voltage dependence of expressed HERG current compared with native "rapid" delayed rectifier K current ... It is widely believed that HERG (human ether-a-go-go-related gene) encodes the major subunit of the cardiac "rapid" delayed rectifier K channel. However, due to rapid inactivation relatively little current flows until the potential becomes less positive than 0 mV. There was an outward current in transfected CHO cells, which developed progressively during the AP plateau and slow repolarisation phase. http://www.pdg.cnb.uam.es/UniPub/iHOP/gp/1644894.html   (402 words)      Organophosphonate Caused Cardiac Toxicity: Action Potential Dynamics in Atrial Tissue - Storming Media This suggests that Class III anti-arrhythmic agents that primarily block these currents in the cardiac cells are important candidates for therapeutics of OP poisoning. Organophosphonate Caused Cardiac Toxicity: Action Potential Dynamics in Atrial Tissue It is known that acetylcholine overload is one of the effects of OP toxicity, but the cellular processes leading to cardiac toxicity are still incompletely understood. http://www.stormingmedia.us/39/3962/A396204.html   (177 words)      lesson2i The CD, Interactive Physiology, is packaged with the 6th edition of Martini's Fundamentals of Anatomy and Physiology and you can play it on any computer. On that CD, go to Cardiovascular System and then go to Cardiac Action Potential. http://dtc.pima.edu/~biology/202alpha/lesson2/lesson2i.htm   (78 words)      hERG cardiac safety pharmacology - Purkinje fibers CRO patch-clamp IC50 determination GLP assays QT interval Laennec Tek : hERG cardiac safety pharmacology - Purkinje fibers - CRO patch-clamp - IC50 determination - GLP assays, QT interval, telemetry, Vascular system, respiratory system, central nervous system, cardiac action potential, QT prolongation, QT interval, channel electrophysiology, ECG, Herg, GLP, Purkinje hERG / cardiac safety pharmacology / Purkinje fibers / CRO / Patch-clamp / IC50 determination / GLP / Assays QT interval hERG cardiac safety pharmacology - Purkinje fibers CRO patch-clamp IC50 determination GLP assays QT interval http://www.laennec-tek.com   (94 words)      CiteULike: The Different Effects of Phenothiazines on Cardiac Action Potential Duration The Different Effects of Phenothiazines on Cardiac Action Potential Duration CiteULike: The Different Effects of Phenothiazines on Cardiac Action Potential Duration Note: You or your institution must have access rights to this article. http://www.citeulike.org/article/88333   (56 words)      An Ion Channel Model of Cardiac Action Potential Propagation An Ion Channel Model of Cardiac Action Potential Propagation A two-dimensional detailed ion channel model of abnormal cardiac action potential propagation This is a conference proceedings paper based on a talk I gave at the Computers in Cardiology meeting held in Cleveland, OH, Sept. 13-16, 1998. http://otani.vet.cornell.edu/oolrsim/cic98.html   (82 words)      Globus-Based Grid Computing Simulations of Action Potential Propagation on Cardiac Tissues Globus-Based Grid Computing Simulations of Action Potential Propagation on Cardiac Tissues For further information about this item go to: http://wotan.liu.edu/docis/dbl/eurpar/2004__444_GGCSOA.htm   (50 words)

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