• Previous work has suggested that double potentials in extracellular electrograms may help to locate the slow pathway so as to target the delivery of radiofrequency energy.1'3 The origin of double potentials is unknown, but it has been suggested that they are caused by depolarization of the slow pathway or its atrial termination. (pdfkul.com)
  • The high-frequency component was caused by depolarization of atrial-type cells in the deep subendocardial layer. (pdfkul.com)
  • A paced ventricular beat is triggered in response to a sensed intrinsic atrial depolarisation. (thebluntdissection.org)
  • Premature atrial depolarizations arise within atrial foci not often associated with the SA node. (veteriankey.com)
  • These electrodes detect the small electrical changes that are a consequence of cardiac muscle depolarization followed by repolarization during each cardiac cycle (heartbeat). (wikipedia.org)
  • Although ventricular activation from the His Purkinje system starts in the endocardium and spreads to the epicardium the epicardium actually repolarizes first because it has a shorter action potential duration.6 As a result epicardial pacing prolongs repolarization in the endocardium with its longer baseline action potential duration leading to an increase in the QT interval and prolongation of the transmural dispersion of repolarization. (immune-source.com)
  • For example, the value of an ion channel conductance at various points across the myocardial wall might vary linearly between two values as a function of distance from the epicardium to the endocardium. (medunigraz.at)
  • In this way, the overall magnitude and direction of the heart's electrical depolarization is captured at each moment throughout the cardiac cycle. (wikipedia.org)
  • To put this another way, contractility is the ability of cardiac muscle cells to contract in the ventricles after depolarization. (nursesed.net)
  • Depolarization of cardiac cells involves a rapid influx of the positive ion's sodium and calcium. (diseasesdic.com)
  • During each heartbeat, a healthy heart has an orderly progression of depolarization that starts with pacemaker cells in the sinoatrial node, spreads throughout the atrium, and passes through the atrioventricular node down into the bundle of His and into the Purkinje fibers, spreading down and to the left throughout the ventricles. (wikipedia.org)
  • This upward drift towards a gradual DEPOLARIZATION is called the pacemaker potential. (studymoose.com)
  • the specific differences in ion channels and mechanisms of polarization give rise to unique properties of SA node cells, most importantly the spontaneous depolarizations necessary for the SA node's pacemaker activity. (wikipedia.org)
  • This orderly pattern of depolarization gives rise to the characteristic ECG tracing. (wikipedia.org)
  • The positively charged ions entering the cell cause the depolarization characteristic of an action potential. (wikipedia.org)
  • Monomorphic VT is typically initiated by a premature ventricular beat and maintained by scar 4 while torsade de pointe is usually brought on by early after depolarizations (EADs) and maintained by functional reentry. (immune-source.com)
  • A paced ventricular beat will be triggered if an intrinsic depolarisation fails to occur during a set, programmed interval. (thebluntdissection.org)
  • They are originated from the Bundle of His and are branched and distributed across the ventricular wall below the endocardium within the space called the subendocardium. (microbenotes.com)
  • It occurs when the rate of depolarization of the SA node falls below the rate of the AV node. (iiab.me)
  • The low-frequency component was caused by depolarization of cells with nodal characteristics close to the endocardium. (pdfkul.com)
  • On the microscopic level, the wave of depolarization propagates to adjacent cells via gap junctions located on the intercalated disc . (wikipedia.org)
  • duration DURATION Duration of simulation [ms]. Choosing a value of around 70 ms covers activation only and thus yields only the depolarization complex of the ECG. (opencarp.org)
  • Atrioventricular node is responsible for delaying the passage of the electrical impulse to ventricles in order to protect them from fast depolarizations coming from the atria. (bvsalud.org)
  • Isoproterenol slightly increased Purkinje conduction velocity and markedly improved conduction at the PVJ and in the endocardium similarly in the presence or absence of halothane. (silverchair.com)
  • During each heartbeat, a healthy heart has an orderly progression of depolarization that starts with pacemaker cells in the sinoatrial node, spreads throughout the atrium, and passes through the atrioventricular node down into the bundle of His and into the Purkinje fibers, spreading down and to the left throughout the ventricles. (wikipedia.org)
  • irrigating the heart of insulin heart in heart termination and comprising motifs to transgenic opening of these nuclei through Fiscal endocardium cardiomyopathy, may pump Antenatal congestive dogs for the age of body binding. (siriuspixels.com)
  • The electrical axis of the heart is the net direction in which the wave of depolarization travels. (mdwiki.org)
  • from here the wave of depolarisation travels down to the apex of the heart. (mdwiki.org)
  • The hexaxial reference system can be used to visualise the directions in which the depolarisation wave may travel. (mdwiki.org)
  • 23.Detecting and recording the electrical depolarization of the heart muscle. (msudenver.edu)