• The most common sites for accessory pathways are connections between muscle tissue in the atria and the ventricles (atrio-ventricular pathways), bypassing the atrioventricular node. (wikipedia.org)
  • [ 1 ] Currently, Wolff-Parkinson-White (WPW) syndrome is defined as a congenital condition involving abnormal conductive cardiac tissue between the atria and the ventricles that provides a pathway for a reentrant tachycardia circuit, in association with supraventricular tachycardia (SVT). (medscape.com)
  • Accessory pathways are often diagnosed using an electrocardiogram, but characterisation and location of the pathway may require an electrophysiological study. (wikipedia.org)
  • Accessory pathways may not require any treatment, but those causing symptoms may be treated with medication including calcium channel antagonists, beta blockers or flecainide. (wikipedia.org)
  • Alternatively, the electrical conduction through an accessory pathways can be abolished using catheter ablation, potentially offering a permanent cure. (wikipedia.org)
  • These rarer accessory pathways are sometimes collectively referred to as Mahaim pathways or Mahaim fibres. (wikipedia.org)
  • Unlike most atrio-ventricular accessory pathways which conduct electrical impulses at a relatively fixed speed, conduction through a Mahaim pathway varies according to how rapidly it is stimulated. (wikipedia.org)
  • If conduction to the ventricles occurs solely through the pathway (maximal pre-excitation), as occurs during arrhythmias like antidromic atrioventricular re-entrant tachycardia, the ECG appearance is of QRS complexes with a left bundle branch block morphology which can be mistaken for ventricular tachycardia. (wikipedia.org)
  • F. The most common form of paroxysmal supraventricular tachycardia (PSVT) is AV nodal reentry due to dual pathways of excitation in the region of the AV node (see Figure 1). (rjmatthewsmd.com)
  • Rarer sites include connections between atrial muscle and the conducting tissue within the ventricles (atrio-fascicular pathways), between the atrioventricular node and the muscle tissue of the ventricle (nodo-ventricular pathways), and between the conducting tissue of the ventricle and the ventricular muscle (fasciculo-ventricular pathways). (wikipedia.org)
  • Characteristics of individual transport pathways, including their geometry, physico-chemical properties and dynamics are instrumental for understanding of structure-function relationships of these proteins, for the design of new inhibitors and construction of improved biocatalysts. (plos.org)
  • Transport pathways play an essential role in the functioning of a large number of proteins. (plos.org)
  • Specific modalities can be associated with unique peripheral receptors, peripheral axons of stereotyped diameter and specific central projection pathways. (cdc.gov)
  • More frequent stimulation leads to slower conduction, known as decremental conduction. (wikipedia.org)
  • Obtained results clearly demonstrate that analysis of molecular dynamics simulation is essential for the estimation of pathway characteristics and elucidation of the structural basis of the tunnel gating. (plos.org)
  • 1) The authors rightly state the presence of myelination is a main structural determinant of conduction velocity. (scholarpedia.org)
  • 3) A figure illustrating the empirical relationship between axon diameter and conduction velocity for myelinated and unmyelinated axons, a key structural factor in axonal conduction delays , would aid the reader's understanding. (scholarpedia.org)
  • Second, I think further explanation is required regarding myelin thickness and the relationship between axon diameter and conduction velocity for unmyelinated axons. (scholarpedia.org)
  • While the evidence for an approximately linear relationship between axon diameter and conduction velocity for myelinated axons is reasonably good, the empirical support for conduction velocity increasing with the square root of axon diameter for unmyelinated axons is less clear cut. (scholarpedia.org)
  • For example, Hoffmeister et al (1991 Neuroscience 42: 603) argue their data support an approximately linear axon diameter-conduction velocity relationship for unmyelinated axons. (scholarpedia.org)
  • Chaperonin Containing Tailless Complex Polypeptide 1 (CCT-1) is one of the important elements of protein folding pathway in cells and proteasome is an important component of Adenosine Triphosphate (ATP) dependent protein degradation pathway in cells. (ijpsonline.com)
  • This is an elegantly simple illustration of normal conduction compared to accessory pathway conduction, as seen in Wolff-Parkinson-White conduction. (ecgguru.com)
  • When there is a disturbance in the normal conduction through the fast pathway, the slow pathway may be activated to conduct the excitation wave to the bundle of His, as well as retrograde back to the fast one, and then back again down the slow pathway continuously to produce the PSVT (see Figure 1). (rjmatthewsmd.com)
  • They are involved in the formation of protein folding/degradation signalling pathway, maintaining the normal spatial structure and normal biological function of protein [ 3 ]. (ijpsonline.com)
  • However, due to their slow decremental conduction, during sinus rhythm the 12-lead ECG will often show little pre-excitation. (wikipedia.org)
  • A block of the heart's electrical pathways can cause the signals that trigger the heartbeats to slow down or stop. (mayoclinic.org)
  • G. There is a slow conduction pathway as well as a fast one. (rjmatthewsmd.com)
  • Fourth, there appears to be no mention that conduction properties change during pathway development (e.g. (scholarpedia.org)
  • Given many experiments are conducted on immature brain slices, it would be useful for the reader to be aware that caution in needed when comparing conduction properties measured at different postnatal ages in the same species. (scholarpedia.org)
  • By channel we mean a pathway leading throughout the protein structure, without any interruption by an internal cavity, with both sides open to the surrounding solvent. (plos.org)
  • each half assembles as an α-helical barrel that could potentially serve as a proton conduction pore. (elifesciences.org)
  • In this regard, we are studying proton conduction in solid oxide mater. (researchgate.net)
  • The most common sites for accessory pathways are connections between muscle tissue in the atria and the ventricles (atrio-ventricular pathways), bypassing the atrioventricular node. (wikipedia.org)
  • Rarer sites include connections between atrial muscle and the conducting tissue within the ventricles (atrio-fascicular pathways), between the atrioventricular node and the muscle tissue of the ventricle (nodo-ventricular pathways), and between the conducting tissue of the ventricle and the ventricular muscle (fasciculo-ventricular pathways). (wikipedia.org)
  • Heart block is a delay in the conduction of electrical current as it passes through the conduction system of the heart, including the atrioventricular node, bundle of His, or both bundle branches, all of which are located between the atria and the ventricles. (msdmanuals.com)
  • Seven patients had normal electrophysiology, 16 had a direct accessory atrioventricular pathway, 12 had dual atrioventricular nodal (AH) pathways, five had paroxysmal ventricular tachycardia, six had conduction system disease, and one patient had a left atrial tachycardia. (bmj.com)
  • If conduction to the ventricles occurs solely through the pathway (maximal pre-excitation), as occurs during arrhythmias like antidromic atrioventricular re-entrant tachycardia, the ECG appearance is of QRS complexes with a left bundle branch block morphology which can be mistaken for ventricular tachycardia. (wikipedia.org)
  • not from the ventricles to the atria (retrograde conduction). (wikipedia.org)
  • Pronounced prolongation of retrograde "fast" AH pathway refractoriness was observed in those patients with dual AH pathways. (bmj.com)
  • Anterograde and retrograde accessory pathway refractoriness were both greatly increased. (bmj.com)
  • Patients with left-sided accessory pathways and requiring routine electrophysiological studies were recruited. (medscape.com)
  • Accessory pathways are often diagnosed using an electrocardiogram, but characterisation and location of the pathway may require an electrophysiological study. (wikipedia.org)
  • Acute electrophysiological effects of flecainide acetate on cardiac conduction and refractoriness in man. (bmj.com)
  • An accessory pathway is an additional electrical connection between two parts of the heart. (wikipedia.org)
  • The combination of an accessory pathway that causes pre-excitation with arrhythmias is known as Wolff-Parkinson-White syndrome. (wikipedia.org)
  • Accessory pathways may not require any treatment, but those causing symptoms may be treated with medication including calcium channel antagonists, beta blockers or flecainide. (wikipedia.org)
  • Alternatively, the electrical conduction through an accessory pathways can be abolished using catheter ablation, potentially offering a permanent cure. (wikipedia.org)
  • These rarer accessory pathways are sometimes collectively referred to as Mahaim pathways or Mahaim fibres. (wikipedia.org)
  • Unlike most atrio-ventricular accessory pathways which conduct electrical impulses at a relatively fixed speed, conduction through a Mahaim pathway varies according to how rapidly it is stimulated. (wikipedia.org)
  • Classical models of arrhythmogenesis predict that shortening of refractoriness and slowing of conduction are proarrhythmic. (medscape.com)
  • The mixed-ionic electronic conduction (MIEC) of gadolinium doped ceria (CGO) under reduced oxygen conditions makes it an excellent fuel electrode material for SOFC/SOEC applications. (researchgate.net)
  • Results: Cardiac BPA exposure resulted in prolonged PR segment and decreased epicardial conduction velocity (0.1-100 μM BPA), prolonged action potential duration (1-100 μM BPA), and delayed atrioventricular conduction (10-100 μM BPA). (nih.gov)
  • These pathways can lead to abnormal heart rhythms or arrhythmias associated with symptoms of palpitations. (wikipedia.org)
  • However, due to their slow decremental conduction, during sinus rhythm the 12-lead ECG will often show little pre-excitation. (wikipedia.org)
  • Overview of Abnormal Heart Rhythms Abnormal heart rhythms (arrhythmias) are sequences of heartbeats that are irregular, too fast, too slow, or conducted via an abnormal electrical pathway through the heart. (msdmanuals.com)
  • They set off cellular signalling pathways, so conduction through these channels is tightly controlled. (edu.au)
  • Elucidating cellular factors and molecular pathways governing electrical maturation of early hESC-CMs would enable engineered microenvironment to create electrophysiologically compatible hESC-CMs for a safe cell-based therapy of cardiovascular diseases. (ca.gov)
  • Wnt signaling pathways constitute a group of signal transduction pathways that direct many physiological processes, such as development, growth, and differentiation. (mdpi.com)
  • Peritoneal stomata constitute the principal pathways for the drainage of intraperitoneal contents from the PERITONEAL CAVITY to the LYMPHATIC SYSTEM. (bvsalud.org)
  • Conclusions: Our results show that acute BPA exposure slowed electrical conduction in excised hearts from female rats. (nih.gov)
  • Atrioventricular Block Atrioventricular block is a delay in the conduction of electrical current as it passes through the atrioventricular conduction system. (msdmanuals.com)
  • Electrical signals in your heart usually travel along certain pathways to tell the heart to beat regularly. (nih.gov)
  • People who have WPW syndrome are born with an extra electrical pathway that changes the way these signals travel. (nih.gov)
  • Axonal sprouting of corticospinal and raphespinal fibers in NgR(310)ecto-Fc-treated animals correlates with improved spinal cord electrical conduction and improved locomotion. (jneurosci.org)
  • Mahaim pathways are typically seen on the right side of the heart, with their ventricular connection lying within or close to the right bundle branch. (wikipedia.org)
  • These findings emphasize the importance of examining BPA's effect on heart electrophysiology and determining whether chronic in vivo exposure can cause or exacerbate conduction abnormalities in patients with preexisting heart conditions and in other high-risk populations. (nih.gov)
  • Contraction of the muscle fibers in the heart is controlled by electricity that flows through the heart in a precise manner along distinct pathways at a controlled speed. (msdmanuals.com)
  • Wolff-Parkinson-White (WPW) syndrome is a conduction disorder that can make your heart beat too quickly or with an irregular rhythm. (nih.gov)
  • Wolff-Parkinson-White (WPW) syndrome Reentrant supraventricular tachycardias (SVT) involve reentrant pathways with a component above the bifurcation of the His bundle. (merckmanuals.com)
  • As part of a composite electrode (Ni/CGO), the nickel phase offers a fast electronic conduction pathway to the current collector and may act as an electrocatalyst at t. (researchgate.net)
  • It should be administered, however, with caution to patients with pre-existing conduction system disease. (bmj.com)
  • And then tomorrow we will continue with sessions on the regulatory pathway for focused ultrasound neuromodulation as a treatment, experimental design and planning, and optimizing target engagement: parameter space and effects. (nih.gov)
  • Alterations of cAMP signaling may also have pleiotropic effects on numerous signaling pathways. (jneurosci.org)
  • Some pathways may activate a region of ventricular muscle earlier than would normally occur, referred to as pre-excitation, and this may be seen on an electrocardiogram. (wikipedia.org)
  • Here, we report a topochemical synthesis strategy (namely intercalation paths) to visualize the real-time synchronous cation transport and electron conduction pathways and realize the control of intercalation structures and metal oxides' conductivity. (nature.com)
  • A series of higher-order Ruddlesden-Popper phase materials - La 3 PrNi 3 O 9.76 (L3P1N3), La 2 Pr 2 Ni 3 O 9.65 (L2P2N3) and LaPr 3 Ni 3 O 9.76 (L1P3N3) - were synthesised and investigated by neutron powder diffraction to understand the oxygen defect structure and propose possible pathways for oxygen transport in these materials. (researchgate.net)
  • Here, we report a visual topochemical synthesis strategy to control intercalation pathways and structures and realize the rapid synthesis of flexible conductive metal oxide films in one minute at room temperature. (nature.com)
  • 23. Are flash-evoked visual potentials useful for intraoperative monitoring of visual pathway function? (nih.gov)
  • 39. Retinal function and neural conduction along the visual pathways in affected and unaffected carriers with Leber's hereditary optic neuropathy. (nih.gov)
  • With these established methods, we further studied the role of endothelial cells (ECs) and their molecular pathways in inducing EP maturation of primitive hESC-CMs. (ca.gov)
  • In particular, we found that ECs significant influenced the expression of several specific types of ion channels of early hESC-CMs via paracrine pathways. (ca.gov)
  • This review provides an overview of basic concept of IL-6 signaling pathway as well as the interplay between IL-6 and renal-resident cells, including podocytes, mesangial cells, endothelial cells, and tubular epithelial cells. (frontiersin.org)