scholarly journals Initiation and dynamics of a spiral wave around an ionic heterogeneity in a model for human cardiac tissue

2013 ◽  
Vol 88 (6) ◽  
Author(s):  
Arne Defauw ◽  
Peter Dawyndt ◽  
Alexander V. Panfilov
Keyword(s):  
Cardiac Tissue ◽  
Spiral Wave ◽  
Human Cardiac Tissue

Turbulent electrical activity at sharp-edged inexcitable obstacles in a model for human cardiac tissue

2014 ◽  
Vol 307 (7) ◽  
pp. H1024-H1035 ◽  
Author(s):  
Rupamanjari Majumder ◽  
Rahul Pandit ◽  
A. V. Panfilov
Keyword(s):  
Wave Propagation ◽  
Cardiac Tissue ◽  
Spiral Wave ◽  
Spiral Waves ◽  
Delayed Rectifier ◽  
High Frequency Stimulation ◽  
Secondary Importance ◽  
Ionic Model ◽  
Delayed Rectifier Current ◽  
Human Cardiac Tissue

Wave propagation around various geometric expansions, structures, and obstacles in cardiac tissue may result in the formation of unidirectional block of wave propagation and the onset of reentrant arrhythmias in the heart. Therefore, we investigated the conditions under which reentrant spiral waves can be generated by high-frequency stimulation at sharp-edged obstacles in the ten Tusscher-Noble-Noble-Panfilov (TNNP) ionic model for human cardiac tissue. We show that, in a large range of parameters that account for the conductance of major inward and outward ionic currents of the model [fast inward Na+ current ( INa), L—type slow inward Ca2+ current ( ICaL), slow delayed-rectifier current ( IKs), rapid delayed-rectifier current ( IKr), inward rectifier K+ current ( IK1)], the critical period necessary for spiral formation is close to the period of a spiral wave rotating in the same tissue. We also show that there is a minimal size of the obstacle for which formation of spirals is possible; this size is ∼2.5 cm and decreases with a decrease in the excitability of cardiac tissue. We show that other factors, such as the obstacle thickness and direction of wave propagation in relation to the obstacle, are of secondary importance and affect the conditions for spiral wave initiation only slightly. We also perform studies for obstacle shapes derived from experimental measurements of infarction scars and show that the formation of spiral waves there is facilitated by tissue remodeling around it. Overall, we demonstrate that the formation of reentrant sources around inexcitable obstacles is a potential mechanism for the onset of cardiac arrhythmias in the presence of a fast heart rate.

scholarly journals Alternans and spiral breakup in a human ventricular tissue model

2006 ◽  
Vol 291 (3) ◽  
pp. H1088-H1100 ◽  
Author(s):  
K. H. W. J. ten Tusscher ◽  
A. V. Panfilov
Keyword(s):  
Cardiac Tissue ◽  
Cell Model ◽  
Sodium Current ◽  
Single Cells ◽  
Spiral Wave ◽  
Western World ◽  
Cardiac Memory ◽  
Electrical Instability ◽  
Ventricular Tissue ◽  
Human Cardiac Tissue

Ventricular fibrillation (VF) is one of the main causes of death in the Western world. According to one hypothesis, the chaotic excitation dynamics during VF are the result of dynamical instabilities in action potential duration (APD) the occurrence of which requires that the slope of the APD restitution curve exceeds 1. Other factors such as electrotonic coupling and cardiac memory also determine whether these instabilities can develop. In this paper we study the conditions for alternans and spiral breakup in human cardiac tissue. Therefore, we develop a new version of our human ventricular cell model, which is based on recent experimental measurements of human APD restitution and includes a more extensive description of intracellular calcium dynamics. We apply this model to study the conditions for electrical instability in single cells, for reentrant waves in a ring of cells, and for reentry in two-dimensional sheets of ventricular tissue. We show that an important determinant for the onset of instability is the recovery dynamics of the fast sodium current. Slower sodium current recovery leads to longer periods of spiral wave rotation and more gradual conduction velocity restitution, both of which suppress restitution-mediated instability. As a result, maximum restitution slopes considerably exceeding 1 (up to 1.5) may be necessary for electrical instability to occur. Although slopes necessary for the onset of instabilities found in our study exceed 1, they are within the range of experimentally measured slopes. Therefore, we conclude that steep APD restitution-mediated instability is a potential mechanism for VF in the human heart.

The Nonselective β-Blocker Carvedilol Suppresses Apoptosis in Human Cardiac Tissue: A Pilot Study

2010 ◽  
Vol 13 (4) ◽  
pp. E218-E222 ◽  
Author(s):  
Engin Usta ◽  
Migdat Mustafi ◽  
Andreas Straub ◽  
Gerhard Ziemer
Keyword(s):  
Pilot Study ◽  
Cardiac Tissue ◽  
Β Blocker ◽  
Human Cardiac Tissue

scholarly journals Cardiac Organoids to Model and Heal Heart Failure and Cardiomyopathies

Biomedicines ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 563
Author(s):  
Magali Seguret ◽  
Eva Vermersch ◽  
Charlène Jouve ◽  
Jean-Sébastien Hulot
Keyword(s):  
Tissue Engineering ◽  
Drug Testing ◽  
Cardiac Tissue ◽  
Cardiac Tissue Engineering ◽  
Cardiac Cells ◽  
Cardiac Functions ◽  
Different Types ◽  
Recent Developments ◽  
Human Cardiac Tissue ◽  
Key Aspects

Cardiac tissue engineering aims at creating contractile structures that can optimally reproduce the features of human cardiac tissue. These constructs are becoming valuable tools to model some of the cardiac functions, to set preclinical platforms for drug testing, or to alternatively be used as therapies for cardiac repair approaches. Most of the recent developments in cardiac tissue engineering have been made possible by important advances regarding the efficient generation of cardiac cells from pluripotent stem cells and the use of novel biomaterials and microfabrication methods. Different combinations of cells, biomaterials, scaffolds, and geometries are however possible, which results in different types of structures with gradual complexities and abilities to mimic the native cardiac tissue. Here, we intend to cover key aspects of tissue engineering applied to cardiology and the consequent development of cardiac organoids. This review presents various facets of the construction of human cardiac 3D constructs, from the choice of the components to their patterning, the final geometry of generated tissues, and the subsequent readouts and applications to model and treat cardiac diseases.

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