October 1, 1988Journal of Cardiovascular Pharmacology
Tonic and Phasic Vmax Block Induced by 5-Hydroxypropafenone in Guinea Pig Ventricular Muscles
Why the study?
Does 5-hydroxypropafenone induce tonic and phasic Vmax block in isolated guinea pig ventricular muscles?
Population
Isolated guinea pig papillary muscles
Comparison
5-hydroxypropafenone (10^-7 M to 5 X 10^-5 M) vs Normally polarized fibers under 5.4 mM K
Design
Preclinical
Authors
Discussion
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Member takes
Implication
Supports sodium channel blockade as key to 5-hydroxypropafenone effects; leaves open translation to human antiarrhythmic use.
Structured PICO
Does 5-hydroxypropafenone induce tonic and phasic Vmax block in isolated guinea pig ventricular muscles?
P
Population
Isolated guinea pig papillary muscles
I
Intervention
5-hydroxypropafenone (10^-7 M to 5 X 10^-5 M)
C
Comparator
Normally polarized fibers under 5.4 mM K (baseline conditions)
O
Outcome
Vmax and amplitude of the action potential, resting membrane potential, and action potential durationsurrogate
5-hydroxypropafenone exhibits phasic inhibitory action on fast sodium channels similar to other class Ic antiarrhythmic drugs, which likely plays a major role in its antiarrhythmic effect.
Cite This Study
Valenzuela et al. (1988) studied this question.