What does this research mean for the field?

Stretching cardiac Purkinje fibers increases conduction velocity without altering membrane excitability, a change mediated primarily by the unfolding of redundant surface membranes. Novelty: ClaimNovelty.INCREMENTAL. Consensus alignment: ConsensusAlignment.SUPPORTS_CONSENSUS.

What question did this study set out to answer?

To determine how mechanical stretch alters conduction velocity, membrane excitability, and structural cable properties in cardiac Purkinje fibers.

September 1, 1979AJP Cell Physiology

Effect of stretch on conduction velocity and cable properties of cardiac Purkinje fibers

View Full Paper

Ask AI

Bookmark

Why the study?

Does stretch affect conduction velocity and membrane properties in cardiac Purkinje fibers?

Population

Cardiac Purkinje fibers

Comparison

Stretch to 30% and 50% in excess of their slack… vs Before stretch (slack length)

Design

Preclinical

Authors

GDG. DominguezSan Sebastián University HFHarry A. FozzardUniversity of Vermont

Discussion

Member takes

Implication

May affect Purkinje conduction in dilatation; extends membrane-unfolding models but leaves open human relevance.

Key Points

To determine how mechanical stretch alters conduction velocity, membrane excitability, and structural cable properties in cardiac Purkinje fibers.
Examined isolated cardiac Purkinje fibers before and after applying 30% and 50% stretch relative to slack length.
Measured resting potentials, conduction velocity, and action potential parameters including upstroke velocity, amplitude, duration, and foot time constant.
Performed cable analyses to evaluate geometric models of stretch, specifically comparing membrane unfolding versus uncoiling.
Conduction velocity increased by 26% following a 50% stretch above slack length.
Resting potential (averaging -77 mV), action potential amplitude, maximal upstroke velocity, duration, and time constant of the foot did not change with stretch.
Cable analysis demonstrated that length increases occurred via mixed mechanisms, with approximately two-thirds attributable to membrane unfolding and one-third to uncoiling.

Structured PICO

Does stretch affect conduction velocity and membrane properties in cardiac Purkinje fibers?

Population

Cardiac Purkinje fibers

Intervention

Stretch to 30% and 50% in excess of their slack length

Comparator

Before stretch (slack length)

Outcome

Conduction velocity and membrane propertiessurrogate

Stretch increases conduction velocity in cardiac Purkinje fibers likely due to unfolding of the surface membrane, which may be important in cardiac dilatation.

Cite This Study

Dominguez et al. (1979) studied this question.

synapsesocial.com/papers/6a1bf8811567d2fc4d5f593e https://doi.org/10.1152/ajpcell.1979.237.3.c119

View Full Paper

Ask AI

Bookmark

Effect of stretch on conduction velocity and cable properties of cardiac Purkinje fibers

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Effect of stretch on conduction velocity and cable properties of cardiac Purkinje fibers

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Also Consider

Also Consider