The Simulation of Repolarization Events of the Cardiac Purkinje Fiber Action Potential

1982 ◽  
Vol BME-29 (7) ◽  
pp. 481-493 ◽  
Author(s):  
Jean-Pierre Drouhard ◽  
Fernand A. Roberge
Keyword(s):  
Action Potential ◽  
Purkinje Fiber ◽  
Fiber Action

Developmental Electrophysiology of Encainide and Its Major Metabolites on the Purkinje Fiber Action Potential

Neonatology ◽  
1994 ◽  
Vol 66 (6) ◽  
pp. 330-338
Author(s):  
Christopher L. Case ◽  
Kenneth W. Hewett ◽  
Paul C. Gillette
Keyword(s):  
Action Potential ◽  
Purkinje Fiber ◽  
Fiber Action

Electrophysiologic effects of FPL 13210 on canine Purkinje fiber action potential duration and Vmax comparison to disopyramide

1991 ◽  
Vol 5 (1) ◽  
pp. 139-146 ◽  
Author(s):  
T. K. Knilans ◽  
A. Varró ◽  
P. P. Nánási ◽  
R. J. Murray ◽  
F. C. Kaiser ◽  
...  
Keyword(s):  
Action Potential ◽  
Action Potential Duration ◽  
Purkinje Fiber ◽  
Fiber Action

Effect of tetrodotoxin on action potentials of the conducting system in the dog heart

1979 ◽  
Vol 236 (4) ◽  
pp. H561-H567 ◽  
Author(s):  
E. Coraboeuf ◽  
E. Deroubaix ◽  
A. Coulombe
Keyword(s):  
Action Potential ◽  
Action Potentials ◽  
Sodium Current ◽  
Purkinje Fiber ◽  
Conducting System ◽  
Gating Mechanism ◽  
Inactivation Mechanism ◽  
Current Flows ◽  
Maximum Rate Of Rise ◽  
Fiber Action

Tetrodotoxin (TTX) shortens Purkinje fiber action potential duration (APD) at concentrations (greater than or equal to 3.3 x 10(-8) M) lower than that at which the maximum rate of rise decreases (approximately 10(-6) M). The shortening effect of TTX occurs either at low or high driving rate and is much greater in Purkinje fibers than in bundle branch and muscle fibers. As a result, at a TTX concentration of 1.3 x 10(-6) M, the APD is no longer statistically different all along the conducting system, i.e., the gating mechanism described by Myerburg et al. (Circ. Res. 26: 361-378, 1970) is suppressed. It is concluded that this gating mechanism is attributable, at least in part, to the existence of a TTX-sensitive inward sodium current lengthening the plateau of the Purkinje fiber action potential. Our experimental results and reconstruction of Purkinje fiber action potentials suggest that this current, which is more sensitive to TTX than the normal rapid sodium current, flows through a background sodium conductance or/and a small proportion of sodium channels with no inactivation mechanism (or inactivation mechanism different from normal). The importance of this finding for the mechanism of action of antiarrhythmic drugs is pointed out.

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