| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
1 Todd Franklin Cardiac Research Laboratory, The Children's Heart Center, Department of Pediatrics, Emory University, Atlanta, Georgia 30322; 2 Department of Medical Physiology and Sports Medicine, Utrecht University, 3584 CG Utrecht, The Netherlands; and Academic Medical Center, University of Amsterdam, Department of Physiology, 1105 AZ Amsterdam, The Netherlands
Tachycardias can be produced when focal activity at ectopic locations in either the atria or the ventricles propagates into the surrounding quiescent myocardium. Isolated rabbit atrioventricular nodal cells were coupled by an electronic circuit to a real-time simulation of an array of cell models. We investigated the critical size of an automatic focus for the activation of two-dimensional arrays made up of either ventricular or atrial model cells. Over a range of coupling conductances for the arrays, the critical size of the focus cell group for successful propagation was smaller for activation of an atrial versus a ventricular array. Failure of activation of the arrays at smaller focus sizes was due to the inhibition of pacing of the nodal cells. At low levels of coupling conductance, the ventricular arrays required larger sizes of the focus due to failure of propagation even when the focus was spontaneously active. The major differences between activation of the atrial and ventricular arrays is due to the higher membrane resistance (lower inward rectifier current) of the atrial cells.
action potentials; electrophysiology; arrhythmia; intercellular coupling; mathematical simulation; rabbit; artioventricular node
This article has been cited by other articles:
|
|
 |
|
  I. Liuba and H. Walfridsson Focal atrial tachycardia: increased electrogram fractionation in the vicinity of the earliest activation site Europace, October 1, 2008; 10(10): 1195 - 1204. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. B. Caref, M. Boutjdir, H. D. Himel, and N. El-Sherif Role of subendocardial Purkinje network in triggering torsade de pointes arrhythmia in experimental long QT syndrome Europace, October 1, 2008; 10(10): 1218 - 1223. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Y. Kurata, H. Matsuda, I. Hisatome, and T. Shibamoto Effects of pacemaker currents on creation and modulation of human ventricular pacemaker: theoretical study with application to biological pacemaker engineering Am J Physiol Heart Circ Physiol, January 1, 2007; 292(1): H701 - H718. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. Wilders Dynamic clamp: a powerful tool in cardiac electrophysiology J. Physiol., October 15, 2006; 576(2): 349 - 359. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Arutunyan, A. Pumir, V. Krinsky, L. Swift, and N. Sarvazyan Behavior of ectopic surface: effects of {beta}-adrenergic stimulation and uncoupling Am J Physiol Heart Circ Physiol, December 1, 2003; 285(6): H2531 - H2542. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Arutunyan, L. M. Swift, and N. Sarvazyan Initiation and propagation of ectopic waves: insights from an in vitro model of ischemia-reperfusion injury Am J Physiol Heart Circ Physiol, August 1, 2002; 283(2): H741 - H749. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
