accessory pathway


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Related to accessory pathway: concealed accessory pathway

pathway

 [path´wa]
a course usually followed. In neurology, the nerve structures through which a sensory impression is conducted to the cerebral cortex (afferent pathway), or through which an impulse passes from the brain to the skeletal musculature (efferent pathway). Also used alone to indicate a sequence of reactions that convert one biological material to another (metabolic pathway).
accessory pathway (accessory conduction pathway) extra muscle tissue between the atrium and ventricle that bypasses all or part of the normal conduction system. When the ventricles are activated prematurely via this pathway, initial forces are slow, producing the delta wave of wolff-parkinson-white syndrome, and preexcitation is said to exist; the delta wave causes the PR interval to shorten and the QRS interval to broaden.
alternative complement pathway see complement.
amphibolic pathway a group of metabolic reactions with a dual function, providing small metabolites for further catabolism to end products or for use as precursors in synthetic, anabolic reactions. The tricarboxylic acid cycle is an example. See also anabolism and catabolism.
biosynthetic pathway the sequence of enzymatic steps in the synthesis of a specific end-product in a living organism.
classical complement pathway see complement.
common pathway of coagulation the steps in the mechanism of coagulation (see clotting) from the activation of factor x through the conversion of fibrinogen to fibrin. See also intrinsic pathway of coagulation and extrinsic pathway of coagulation.
concealed accessory pathway an accessory pathway that has only retrograde conduction; thus its PR and QRS complexes are normal on the electrocardiogram, but there is a tendency to develop premature supraventricular tachycardia. If atrial fibrillation develops, conduction will proceed across the atrioventricular node.
Embden-Meyerhof pathway the series of enzymatic reactions in the anaerobic conversion of glucose to lactic acid, resulting in energy in the form of adenosine triphosphate (ATP).
extrinsic pathway of coagulation the mechanism that produces fibrin following tissue injury, beginning with formation of an activated complex between tissue factor and factor vii and leading to activation of factor x, which induces the reactions of the common pathway of coagulation. See also intrinsic pathway of coagulation.
final common pathway
1. the motor neurons by which nerve impulses from many central sources pass to a muscle or gland in the periphery.
2. any mechanism by which several independent effects exert a common influence.
intrinsic pathway of coagulation a sequence of reactions leading to fibrin formation, beginning with the contact activation of factor xii. This is followed by the sequential activation of factors xi and ix, which results in the activation of factor x. Activated factor X (factor Xa) initiates the common pathway of coagulation. See also extrinsic pathway of coagulation.
pentose phosphate pathway a pathway of hexose oxidation in which glucose-6-phosphate undergoes two successive oxidations by NADP, the final forming a pentose phosphate.
References in periodicals archive ?
Wang et al., "Development and validation of an ECG algorithm for identifying accessory pathway ablation site in Wolff-Parkinson-White syndrome," Journal of Cardiovascular Electrophysiology, vol.
Radio frequency ablation of left - sided accessory pathways: transaortic versus transseptal approach.
Accessory pathway locations determined by the electrophysiological study are shown in Table-1.
There is no role for medical therapy in the treatment of pre-excited AF, as beta-blockers, calcium channel blockers, adenosine and digoxin do not block and may enhance conduction over an accessory pathway, resulting in very rapid ventricular response with cardiac arrest.
Propofol has no effect on the refractory period of accessory pathways. Etomidate causes minimal myocardial depression and alterations in sympathetic functions.
Wolff-Parkinson-White syndrome and atrial fibrillation: relation between refractory period of accessory pathway and ventricular rate during atrial fibrillation.
This is because the loss of the delta wave shows that the accessory pathway cannot conduct electrical impulses at a high rate.
Baseline electrocardiogram (ECG) revealed delta wave pattern consistent with the presence of a right sided accessory pathway (AP).
Late clinical outcome after successful radiofrequency ablation of accessory pathways. Eur Heart J.
of Maastricht, the Netherlands) discuss variant forms of preexcitation syndromes that are not well known, and provide variant accessory pathways, their history and anatomy.
This turf reconfiguration will likely come about due to looming technologic advances, including genomic screening for susceptibility to sudden cardiac death, noninvasive mapping of the heart to pinpoint the site of ventricular tachycardia or accessory pathways, noninvasive autonomic imaging of sympathetic enervation of the heart, and vagal imaging of the ventricle.
This turf reconfiguration will likely come about due to advances such as genomic screening for susceptibility to sudden cardiac death, noninvasive mapping of the heart to pinpoint the site of ventricular tachycardia or accessory pathways, noninvasive autonomic imaging of sympathetic enervation of the heart, and vagal imaging of the ventricle.