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Image-Based Structural Modeling of the Cardiac Purkinje Network.

Liu BR, Cherry EM - Biomed Res Int (2015)

Bottom Line: The Purkinje network is a specialized conduction system within the heart that ensures the proper activation of the ventricles to produce effective contraction.To allow for greater realism in Purkinje structural models, we present a method for creating three-dimensional Purkinje networks based directly on imaging data.Using this method, we create models for the combined ventricle-Purkinje system that can fully activate the ventricles through a stimulus delivered to the Purkinje network and can produce simulated activation sequences that match experimental observations.

View Article: PubMed Central - PubMed

Affiliation: School of Mathematical Sciences, Rochester Institute of Technology, Rochester, NY 14623, USA.

ABSTRACT
The Purkinje network is a specialized conduction system within the heart that ensures the proper activation of the ventricles to produce effective contraction. Its role during ventricular arrhythmias is less clear, but some experimental studies have suggested that the Purkinje network may significantly affect the genesis and maintenance of ventricular arrhythmias. Despite its importance, few structural models of the Purkinje network have been developed, primarily because current physical limitations prevent examination of the intact Purkinje network. In previous modeling efforts Purkinje-like structures have been developed through either automated or hand-drawn procedures, but these networks have been created according to general principles rather than based on real networks. To allow for greater realism in Purkinje structural models, we present a method for creating three-dimensional Purkinje networks based directly on imaging data. Our approach uses Purkinje network structures extracted from photographs of dissected ventricles and projects these flat networks onto realistic endocardial surfaces. Using this method, we create models for the combined ventricle-Purkinje system that can fully activate the ventricles through a stimulus delivered to the Purkinje network and can produce simulated activation sequences that match experimental observations. The combined models have the potential to help elucidate Purkinje network contributions during ventricular arrhythmias.

No MeSH data available.


Related in: MedlinePlus

Isochronal plots showing activation times of the rabbit ventricles in the 3D-3D and 3D-2D models. Colors indicate the time at which each point in the tissue experienced depolarization, with zero corresponding to the first activation within the entire ventricles.
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fig10: Isochronal plots showing activation times of the rabbit ventricles in the 3D-3D and 3D-2D models. Colors indicate the time at which each point in the tissue experienced depolarization, with zero corresponding to the first activation within the entire ventricles.

Mentions: As our next validation step, we aimed to compare simulated activation times in a combined ventricle-Purkinje model with activation times observed in experiments. Toward this end, the three-dimensional Purkinje structures recovered through texture-mapping were used as the conduction system in the development of models of the combined ventricle-Purkinje system. Our goal was to create a model that reproduced key features of the real cardiac conduction system. In particular, we aimed to ensure that our model reproduced the overall progression of the total depolarization (activation) of the ventricles, termed the activation sequence, which has been well characterized [18]. Key features of the activation sequence are those areas that are the first to depolarize: activation begins in the left ventricular endocardial surface, particularly in several isolated spots, in the middle of the septum wall and in the upper portion of the free wall. The last region to depolarize is the right ventricular free wall. Figure 10 shows isochronal plots of the activation times achieved in our models. Importantly, the left ventricular endocardium contains some of the sites of earliest activation, particularly on the septum. The right ventricular free wall is also the last region to depolarize, matching with experimental observations. In addition to achieving a realistic activation sequence, the entire activation of the ventricles occurs in realistic time [18, 24].


Image-Based Structural Modeling of the Cardiac Purkinje Network.

Liu BR, Cherry EM - Biomed Res Int (2015)

Isochronal plots showing activation times of the rabbit ventricles in the 3D-3D and 3D-2D models. Colors indicate the time at which each point in the tissue experienced depolarization, with zero corresponding to the first activation within the entire ventricles.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4637159&req=5

fig10: Isochronal plots showing activation times of the rabbit ventricles in the 3D-3D and 3D-2D models. Colors indicate the time at which each point in the tissue experienced depolarization, with zero corresponding to the first activation within the entire ventricles.
Mentions: As our next validation step, we aimed to compare simulated activation times in a combined ventricle-Purkinje model with activation times observed in experiments. Toward this end, the three-dimensional Purkinje structures recovered through texture-mapping were used as the conduction system in the development of models of the combined ventricle-Purkinje system. Our goal was to create a model that reproduced key features of the real cardiac conduction system. In particular, we aimed to ensure that our model reproduced the overall progression of the total depolarization (activation) of the ventricles, termed the activation sequence, which has been well characterized [18]. Key features of the activation sequence are those areas that are the first to depolarize: activation begins in the left ventricular endocardial surface, particularly in several isolated spots, in the middle of the septum wall and in the upper portion of the free wall. The last region to depolarize is the right ventricular free wall. Figure 10 shows isochronal plots of the activation times achieved in our models. Importantly, the left ventricular endocardium contains some of the sites of earliest activation, particularly on the septum. The right ventricular free wall is also the last region to depolarize, matching with experimental observations. In addition to achieving a realistic activation sequence, the entire activation of the ventricles occurs in realistic time [18, 24].

Bottom Line: The Purkinje network is a specialized conduction system within the heart that ensures the proper activation of the ventricles to produce effective contraction.To allow for greater realism in Purkinje structural models, we present a method for creating three-dimensional Purkinje networks based directly on imaging data.Using this method, we create models for the combined ventricle-Purkinje system that can fully activate the ventricles through a stimulus delivered to the Purkinje network and can produce simulated activation sequences that match experimental observations.

View Article: PubMed Central - PubMed

Affiliation: School of Mathematical Sciences, Rochester Institute of Technology, Rochester, NY 14623, USA.

ABSTRACT
The Purkinje network is a specialized conduction system within the heart that ensures the proper activation of the ventricles to produce effective contraction. Its role during ventricular arrhythmias is less clear, but some experimental studies have suggested that the Purkinje network may significantly affect the genesis and maintenance of ventricular arrhythmias. Despite its importance, few structural models of the Purkinje network have been developed, primarily because current physical limitations prevent examination of the intact Purkinje network. In previous modeling efforts Purkinje-like structures have been developed through either automated or hand-drawn procedures, but these networks have been created according to general principles rather than based on real networks. To allow for greater realism in Purkinje structural models, we present a method for creating three-dimensional Purkinje networks based directly on imaging data. Our approach uses Purkinje network structures extracted from photographs of dissected ventricles and projects these flat networks onto realistic endocardial surfaces. Using this method, we create models for the combined ventricle-Purkinje system that can fully activate the ventricles through a stimulus delivered to the Purkinje network and can produce simulated activation sequences that match experimental observations. The combined models have the potential to help elucidate Purkinje network contributions during ventricular arrhythmias.

No MeSH data available.


Related in: MedlinePlus