[Electrophysiological effects of flecainide acetate on guinea-pig left atrial cells].
Using conventional glass microelectrode technique, electrophysiological effects of flecainide acetate on guinea-pig left atrial muscle fibers were examined. Resting membrane potential was not affected by flecainide at any concentrations tested (10(-7) M-3 X 10(-5) M), although overshoot potential was significantly decreased at the concentration over 3 X 10(-6) M. Effective refractory period significantly increased at 10(-5) M. The reduction of Vmax was about 25% and 50% by 3 X 10(-6) M and 10(-5) M, respectively at 1 Hz. At 3 X 10(-6) M, Vmax decreased by about 10%, 15%, 22%, 33%, and 34% at 0.2, 0.5, 1, 2, and 3 Hz respectively. Flecainide, decreased Vmax of atrial muscle fibers in a dose and frequency dependent manner. It is suggested that flecainide might be effective in the treatment of atrial tachyarrhythmias.
Inoue
D
D
Second Department of Medicine, Kyoto Prefectural University of Medicine.
Shirayama
T
T
Omori
I
I
Sakai
R
R
Tatsumi
T
T
Miyazaki
H
H
Asayama
J
J
Nakagawa
M
M
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D016275:Atrial Function; D004305:Dose-Response Relationship, Drug; D005424:Flecainide / Q000494:pharmacology*; D006168:Guinea Pigs; D006321:Heart / Q000187:drug effects* / Q000502:physiology; D006325:Heart Atria / Q000166:cytology; D066298:In Vitro Techniques; D008839:Microelectrodes
D005424:Flecainide