September 1, 1997AJP Heart and Circulatory Physiology
Role of passive electrical properties during action potential restitution in intact heart
Why the study?
Does cell-to-cell coupling influence action potential duration restitution in intact heart tissue?
Population
Langendorff-perfused guinea pig ventricle and a one-dimensional propagation model using the dynamic Luo-Rudy…
Comparison
Premature pacing at short coupling intervals… vs Pacing remote from the identical recording site…
Design
Preclinical
Authors
Discussion
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Implication
May attenuate repolarization dispersion via cell coupling in tissue; extends single-cell restitution models but leaves open arrhythmia relevance.
Key Points
- This research aims to clarify how passive electrical properties influence action potential duration restitution in heart tissues.
- Measured spatial gradients of transmembrane voltage in Langendorff-perfused guinea pig ventricle using voltage-sensitive dye with high spatial, voltage, and temporal resolutions.
- Investigated nonexponential restitution via a one-dimensional propagation model based on the Luo-Rudy formulation of the ventricular cell.
- At short premature coupling intervals, action potential duration did not shorten in cells near the pacing site, deviating from classical restitution.
- Exponential shortening of action potential duration occurred when pacing was remote from the recording site.
- Axial current from neighboring cells was identified as a key mechanism attenuating spatial gradients of repolarization.
Structured PICO
Does cell-to-cell coupling influence action potential duration restitution in intact heart tissue?
P
Population
Langendorff-perfused guinea pig ventricle and a one-dimensional propagation model using the dynamic Luo-Rudy formulation of the ventricular cell
I
Intervention
Premature pacing at short coupling intervals near (< 3 mm) the site of recording
C
Comparator
Pacing remote from the identical recording site and models in the absence of cell-to-cell coupling
O
Outcome
Action potential duration (APD) restitution and spatial gradients of transmembrane voltagesurrogate
In multicellular tissue, action potential duration restitution is influenced by axial current from neighboring cells, which attenuates dispersion of repolarization during premature stimulation.
Cite This Study
Laurita et al. (1997) studied this question.