What question did this study set out to answer?

Investigate the electrophysiological properties and contractile actions of the class III antiarrhythmic compound E-4031 across distinct guinea pig cardiac preparations.

March 1, 1991Journal of Cardiovascular Pharmacology

Effects of the New Class III Antiarrhythmic Drug E-4031 on Myocardial Contractility and Electrophysiological Parameters

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Why the study?

Does E-4031 alter myocardial contractility and electrophysiological parameters in guinea pig cardiac preparations?

Population

Guinea pig cardiac preparations (left atria, right atria, papillary muscles, isolated ventricular myocytes)

Comparison

E-4031 (concentrations ranging from 10 to 10 M) vs Control

Design

Preclinical

Authors

EWErich WettwerWest German Heart and Vascular Center Essen GSGünter ScholtysikUniversity of Bern ASAndreas SchaadUniversity of Bern

Discussion

Member takes

Implication

Supports class III effects in guinea pig models; leaves open clinical translation and safety.

Key Points

Investigate the electrophysiological properties and contractile actions of the class III antiarrhythmic compound E-4031 across distinct guinea pig cardiac preparations.
Assayed E-4031 across concentration ranges from 10⁻⁸ to 10⁻⁵ M in isolated guinea pig left atria, spontaneously beating right atria, papillary muscles, and single ventricular myocytes.
Quantified alterations in functional refractory period, spontaneous frequency, action potential parameters (APD70, APD90, Vmax, APA), membrane ionic currents (Na+, Ca2+, and IK tail current), and muscle shortening.
E-4031 extended left atrial functional refractory period by up to 45%, reduced spontaneous right atrial rate by 32%, and prolonged ventricular myocyte APD90 from 275 ms to 1,496 ms (pD2 6.5) alongside papillary APD70 increases of 51% to 68%.
Delayed rectifier outward tail current (IK) was reduced by 76% at 10⁻⁷ M without altering Na+ or Ca2+ inward currents, maximum upstroke velocity (Vmax), resting potential, or action potential amplitude.
Contractile force increased by 20% at 3 × 10⁻⁷ M in isolated atria, and cell shortening was correspondingly enhanced in ventricular myocytes.

Structured PICO

Does E-4031 alter myocardial contractility and electrophysiological parameters in guinea pig cardiac preparations?

Population

Guinea pig cardiac preparations (left atria, right atria, papillary muscles, isolated ventricular myocytes)

Intervention

E-4031 (concentrations ranging from 10(-8) to 10(-5) M)

Comparator

Control

Outcome

Electrophysiological parameters (functional refractory period, action potential duration, ion currents) and myocardial contractilitysurrogate

E-4031 acts as a class III antiarrhythmic by selectively reducing outward currents, which prolongs action potential duration and enhances contractility in guinea pig cardiac preparations.

Cite This Study

Wettwer et al. (1991) studied this question.

synapsesocial.com/papers/6a7e06bf8b7e38892f15171c https://doi.org/10.1097/00005344-199103000-00018

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Effects of the New Class III Antiarrhythmic Drug E-4031 on Myocardial Contractility and Electrophysiological Parameters

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Effects of the New Class III Antiarrhythmic Drug E-4031 on Myocardial Contractility and Electrophysiological Parameters

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Also Consider

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