What question did this study set out to answer?

To investigate the influence of cardiac tissue microstructure on the initiation of reentry from focal stimulation inside a poorly coupled region embedded in well-coupled tissue.

March 8, 2014AJP Heart and Circulatory PhysiologyOpen Access

In a computational model of cardiac tissue, breakthroughs at the size scale of a single cell can occur at the boundary of source-load mismatch, allowing focal activations to produce reentry.

Q: What is the clinical evidence from this study?

Study design: Other. Population: Cardiac reentry. Intervention: Microstructural variations (gap junction conductance). Primary outcome: Wavefront breakthrough and reentry.

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Population

Two-dimensional discrete computer models of ventricular monolayers with a central poorly coupled patch…

Design

Preclinical

Key result

In a computational model of cardiac tissue, breakthroughs at the size scale of a single cell can occur at the boundary of source-load mismatch, allowing focal activations to produce reentry.

Authors

MHMarjorie Letitia Hubbard CHCraig S. Henriquez

Discussion

Member takes

Overview

Single-cell scale breakthroughs at source-load mismatch may represent ablation targets in reentry; computational findings leave open clinical translation.

Key Points

To investigate the influence of cardiac tissue microstructure on the initiation of reentry from focal stimulation inside a poorly coupled region embedded in well-coupled tissue.
Constructed 2D discrete computer models of ventricular monolayers (1 × 1 cm) with randomly generated microstructural heterogeneity.
Embedded a central poorly coupled patch (0.40 × 0.40 cm) to model focal activity and simulated unipolar electrogram recordings during progressive reductions in gap junction conductance.
Decreased gap conductance slowed conduction and produced fractionated electrograms with reduced signal amplitude.
Near conduction block limits, single-cell breakthrough sites emerged along the patch boundary, governed by brick-wall structural connectivity that focused electrical current into well-coupled zones.

Structured PICO

Population

Two-dimensional discrete computer models of ventricular monolayers (1 × 1 cm) with a central poorly coupled patch (0.40 × 0.40 cm) representing heterogeneity in cardiac microstructure

Intervention

Focal stimulation inside a poorly coupled region embedded in more well-coupled tissue

Outcome

Initiation of reentry and patterns of abnormal propagation (wavefront breakthrough)surrogate

Computational modeling demonstrates that single-cell breakthroughs at boundaries of source-load mismatch can allow focal activations to produce reentry, suggesting these regions may be identifiable targets for ablation.

Limitations

Two-dimensional computer model rather than three-dimensional structure
Ectopic beats simulated using a point stimulus rather than changing underlying ionic currents
Focal activations simulated in the absence of sinus rhythm

Cite This Study

Hubbard et al. (2014) studied Cardiac reentry. Microstructural variations (gap junction conductance) was evaluated on Wavefront breakthrough and reentry. In a computational model of cardiac tissue, breakthroughs at the size scale of a single cell can occur at the boundary of source-load mismatch, allowing focal activations to produce reentry.

synapsesocial.com/papers/6a155baf37103a43379f9cb4 https://doi.org/10.1152/ajpheart.00385.2013

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March 8, 2014AJP Heart and Circulatory PhysiologyOpen Access

In a computational model of cardiac tissue, breakthroughs at the size scale of a single cell can occur at the boundary of source-load mismatch, allowing focal activations to produce reentry.

View Full Paper

Ask AI

Bookmark

Population

Two-dimensional discrete computer models of ventricular monolayers with a central poorly coupled patch…

Design

Preclinical

Key result

In a computational model of cardiac tissue, breakthroughs at the size scale of a single cell can occur at the boundary of source-load mismatch, allowing focal activations to produce reentry.

Authors

MHMarjorie Letitia Hubbard CHCraig S. Henriquez

Discussion

Member takes

Overview

Single-cell scale breakthroughs at source-load mismatch may represent ablation targets in reentry; computational findings leave open clinical translation.

Key Points

To investigate the influence of cardiac tissue microstructure on the initiation of reentry from focal stimulation inside a poorly coupled region embedded in well-coupled tissue.
Constructed 2D discrete computer models of ventricular monolayers (1 × 1 cm) with randomly generated microstructural heterogeneity.
Embedded a central poorly coupled patch (0.40 × 0.40 cm) to model focal activity and simulated unipolar electrogram recordings during progressive reductions in gap junction conductance.
Decreased gap conductance slowed conduction and produced fractionated electrograms with reduced signal amplitude.
Near conduction block limits, single-cell breakthrough sites emerged along the patch boundary, governed by brick-wall structural connectivity that focused electrical current into well-coupled zones.

Structured PICO

Population

Two-dimensional discrete computer models of ventricular monolayers (1 × 1 cm) with a central poorly coupled patch (0.40 × 0.40 cm) representing heterogeneity in cardiac microstructure

Intervention

Focal stimulation inside a poorly coupled region embedded in more well-coupled tissue

Outcome

Initiation of reentry and patterns of abnormal propagation (wavefront breakthrough)surrogate

Limitations

Two-dimensional computer model rather than three-dimensional structure
Ectopic beats simulated using a point stimulus rather than changing underlying ionic currents
Focal activations simulated in the absence of sinus rhythm

Cite This Study

synapsesocial.com/papers/6a155baf37103a43379f9cb4 https://doi.org/10.1152/ajpheart.00385.2013

View Full Paper

Ask AI

Bookmark