Key result
SC-40230 causes a voltage- and rate-dependent ~56% depression of V̇max in isolated cardiac muscle.
Why the study?
The voltage-, rate-, and concentration-dependent effects of the new antiarrhythmic agent SC-40230 on cardiac action potentials were evaluated to characterize its electrophysiological properties.
Population
Guinea pig papillary muscle, guinea pig atria, and canine Purkinje fibers
Comparison
SC-40230 (racemic and stereoisomers) vs absence of drug (control)
Design
Preclinical electrophysiological study
Authors
Loading...
Provides preclinical profile of SC-40230; leaves open clinical antiarrhythmic utility pending human trials.
Absolute Event Rate: 56% vs 18%
SC-40230 exhibits typical class I antiarrhythmic properties by reducing the maximum rate of depolarization in a voltage- and rate-dependent manner in isolated cardiac tissues.
Martin et al. (1989) studied this question. SC-40230 vs. control was evaluated on steady-state depression of V̇max during a stimulus train of 200 pulses/min. SC-40230 caused a voltage- and rate-dependent reduction of the maximum rate of depolarization (V̇max) in isolated cardiac muscle, with 56% depression at 30 μM compared to 18% in control.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: