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

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

Electromechanical characterization of the effects of racemic sotalol and its optical isomers on isolated canine ventricular trabecular muscles and Purkinje strands

1985 ◽  
Vol 63 (12) ◽  
pp. 1506-1512 ◽  
Author(s):  
David A. Lathrop
Keyword(s):  
Action Potential ◽  
Action Potential Duration ◽  
Torsade De Pointes ◽  
Optical Isomers ◽  
Maximal Increase ◽  
Beta Adrenergic ◽  
Force Development ◽  
Rate Dependent ◽  
Adrenergic Blockers ◽  
Fiber Action

In both isolated canine ventricular trabecular muscle and Purkinje strand preparations, dl-sotalol and its two optical isomers d- and l-sotalol produced a concentration-dependent increase in action potential duration while other transmembrane electrical characteristics were not significantly affected. The magnitude of the increase in action potential durations was greater in Purkinje strand preparations. In Purkinje strand preparations, the effect was rate dependent (i.e., the increase in duration was proportionately greater when stimulation frequency was slowed). From the concentration of each compound calculated to produce a 50% maximal increase in Purkinje fiber action potential durations, d-sotalol appeared to be one to three times more potent than either l-sotalol or the racemate. Each compound appeared to increase force development in ventricular trabecular muscle preparations stimulated at a frequency of 2 Hz. Increased force development was only observed in Purkinje strand preparations stimulated at slower rates (0.5–0.33 Hz). These results are unlike those produced by other beta-adrenergic blockers and suggest that the antiarrhythmic effects of sotalol are related primarily to its effect of action potential duration. The estimated potency ratios established for the effect of dl-sotalol and its optical isomers on both trabeculae and Purkinkje fiber action potential durations (d > dl − l) may indicate that these effects are unrelated to the beta-adrenergic blocking properties of these compounds. The differential effect of sotalol on isolated trabeculae and Purkinje strand preparations may help to explain the clinically reported phenomenon of sotalol-induced torsade de pointes.

Sign in / Sign up

Export Citation Format

Share Document