Multiple sites of modulation of calcium ion movements in cardiac tissue: Implications for cardiac arrhythmias

1986 ◽  
Vol 18 ◽  
pp. 19-19
Author(s):  
W COETZEE ◽  
L OPIE ◽  
F THANDROYEN
Keyword(s):  
Cardiac Arrhythmias ◽  
Calcium Ion ◽  
Cardiac Tissue ◽  
Ion Movements

Radiofrequency Catheter Ablation of Cardiac Arrhythmias

2011 ◽  
Author(s):  
M. Erol Ulucakli
Keyword(s):  
Radiofrequency Ablation ◽  
Catheter Ablation ◽  
Cardiac Arrhythmias ◽  
Radiofrequency Catheter Ablation ◽  
Cardiac Tissue ◽  
Bioheat Transfer ◽  
Temperature Profiles ◽  
Cellular Injury ◽  
Wide Range ◽  
Primary Modality

Radiofrequency ablation could be described as a thermal strategy to destroy a tissue by increasing its temperature and causing anirreversible cellular injury. Radiofrequency ablation is a relatively new modality which has found use in a wide range of medical applications and gained acceptance. RF ablation has been used in destroying tumors in liver, prostate, breast, lung, kidney, bones, and the eye. One of the early applications in clinical setting was its use in treating supraventricular arrhythmias by selectively destroying cardiac tissue. Radiofrequency ablation has become established as the primary modality of transcatheter therapy for the treatment of symptomatic arrhythmias. Radiofrequency catheter ablation of cardiac arrhythmias were investigated using a finite-element based solution of bioheat transfer equation. Spatial and temporal temperature profiles in the cardiac tissue were visualized.

On the mechanism of myocardial sensitization to catecholamines by hydrocarbon anesthetics

1984 ◽  
Vol 62 (2) ◽  
pp. 183-198 ◽  
Author(s):  
A. K. Reynolds
Keyword(s):  
Drug Interaction ◽  
Special Reference ◽  
Cardiac Arrhythmias ◽  
Cardiac Tissue ◽  
Muscle Relaxants ◽  
Future Research ◽  
The Past ◽  
Anesthetic Agents ◽  
Bundle Of His ◽  
Made In

During the past decade, considerable progress has been made in our understanding of the mechanism underlying sensitization of the heart to the arrhythmogenic action of catecholamines by hydrocarbon anesthetics. This review includes the following: a brief discussion on the concepts of the mechanisms of induction of cardiac arrhythmias; recent studies on sensitization with special reference to the primary locus of this action and the principal mechanisms involved; and the contributions made by microelectrode studies on various types of cardiac tissue and the importance of cardiodynamic effects. In addition, atrioventricular conduction studies using bundle of His preparations are described. Drug interaction between anesthetic agents, muscle relaxants, and other drugs are discussed. Suggestions for future research and a section of summary and conclusions are included.

Tumor Cells Induce Platelet Aggregation and Intraplatelet Calcium Ion Movements

Platelets ◽  
1993 ◽  
Vol 4 (5) ◽  
pp. 275-279 ◽  
Author(s):  
L. Pacchiarini ◽  
M. Zucchella ◽  
A. R. Eynard ◽  
G. Grignani
Keyword(s):  
Platelet Aggregation ◽  
Tumor Cells ◽  
Calcium Ion ◽  
Induce Platelet Aggregation ◽  
Ion Movements

scholarly journals Overdrive pacing of spiral waves in a model of human ventricular tissue

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Sergei F. Pravdin ◽  
Timofei I. Epanchintsev ◽  
Alexander V. Panfilov
Keyword(s):  
Cardiac Arrhythmias ◽  
Cardiac Tissue ◽  
Low Voltage ◽  
Spiral Waves ◽  
High Frequency Stimulation ◽  
In Silico Study ◽  
Restitution Curve ◽  
Life Threatening ◽  
Frequency Stimulation ◽  
Human Cardiac Tissue

AbstractHigh-voltage electrical defibrillation remains the only reliable method of quickly controlling life-threatening cardiac arrhythmias. This paper is devoted to studying an alternative approach, low-voltage cardioversion (LVC), which is based on ideas from non-linear dynamics and aims to remove sources of cardiac arrhythmias by applying high-frequency stimulation to cardiac tissue. We perform a detailed in-silico study of the elimination of arrhythmias caused by rotating spiral waves in a TP06 model of human cardiac tissue. We consider three parameter sets with slopes of the APD restitution curve of 0.7, 1.1 and 1.4, and we study LVC at the baseline and under the blocking of INa and ICaL and under the application of the drugs verapamil and amiodarone. We show that pacing can remove spiral waves; however, its efficiency can be substantially reduced by dynamic instabilities. We classify these instabilities and show that the blocking of INa and the application of amiodarone increase the efficiency of the method, while the blocking of ICaL and the application of verapamil decrease the efficiency. We discuss the mechanisms and the possible clinical applications resulting from our study.

Small size ionic heterogeneities in the human heart can attract rotors

2014 ◽  
Vol 307 (10) ◽  
pp. H1456-H1468 ◽  
Author(s):  
Arne Defauw ◽  
Nele Vandersickel ◽  
Peter Dawyndt ◽  
Alexander V. Panfilov
Keyword(s):  
Cardiac Arrhythmias ◽  
In Silico ◽  
Human Heart ◽  
Cardiac Tissue ◽  
Two Dimensional ◽  
Anatomical Model ◽  
Practical Applications ◽  
Ventricular Cells ◽  
Local Properties ◽  
Substantial Distance

Rotors occurring in the heart underlie the mechanisms of cardiac arrhythmias. Answering the question whether or not the location of rotors is related to local properties of cardiac tissue has important practical applications. This is because ablation of rotors has been shown to be an effective way to fight cardiac arrhythmias. In this study, we investigate, in silico, the dynamics of rotors in two-dimensional and in an anatomical model of human ventricles using a Ten Tusscher-Noble-Noble-Panfilov (TNNP) model for ventricular cells. We study the effect of small size ionic heterogeneities, similar to those measured experimentally. It is shown that such heterogeneities cannot only anchor, but can also attract, rotors rotating at a substantial distance from the heterogeneity. This attraction distance depends on the extent of the heterogeneities and can be as large as 5–6 cm in realistic conditions. We conclude that small size ionic heterogeneities can be preferred localization points for rotors and discuss their possible mechanism and value for applications.

scholarly journals Drift of Scroll Wave Filaments in an Anisotropic Model of the Left Ventricle of the Human Heart

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Sergei Pravdin ◽  
Hans Dierckx ◽  
Vladimir S. Markhasin ◽  
Alexander V. Panfilov
Keyword(s):  
Left Ventricle ◽  
Cardiac Arrhythmias ◽  
Human Heart ◽  
Cardiac Tissue ◽  
Three Dimensional ◽  
Excitable Media ◽  
Filament Dynamics ◽  
Myocardial Wall ◽  
Scroll Wave ◽  
Generic Description

Scroll waves are three-dimensional vortices which occur in excitable media. Their formation in the heart results in the onset of cardiac arrhythmias, and the dynamics of their filaments determine the arrhythmia type. Most studies of filament dynamics were performed in domains with simple geometries and generic description of the anisotropy of cardiac tissue. Recently, we developed an analytical model of fibre structure and anatomy of the left ventricle (LV) of the human heart. Here, we perform a systematic study of the dynamics of scroll wave filaments for the cases of positive and negative tension in this anatomical model. We study the various possible shapes of LV and different degree of anisotropy of cardiac tissue. We show that, for positive filament tension, the final position of scroll wave filament is mainly determined by the thickness of the myocardial wall but, however, anisotropy attracts the filament to the LV apex. For negative filament tension, the filament buckles, and for most cases, tends to the apex of the heart with no or slight dependency on the thickness of the LV. We discuss the mechanisms of the observed phenomena and their implications for cardiac arrhythmias.

Basic Mechanisms of Cardiac Impulse Propagation and Associated Arrhythmias

2004 ◽  
Vol 84 (2) ◽  
pp. 431-488 ◽  
Author(s):  
ANDRÉ G. KLÉBER ◽  
YORAM RUDY
Keyword(s):  
Computer Simulations ◽  
Cardiac Arrhythmias ◽  
Cardiac Tissue ◽  
Cell Communication ◽  
Cardiac Cells ◽  
Tissue Structure ◽  
Strong Interactions ◽  
Complex Interactions ◽  
Cardiac Impulse ◽  
Impulse Propagation

Kléber, André G., and Yoram Rudy. Basic Mechanisms of Cardiac Impulse Propagation and Associated Arrhythmias. Physiol Rev 84: 431–488, 2004; 10.1152/physrev.00025.2003.—Propagation of excitation in the heart involves action potential (AP) generation by cardiac cells and its propagation in the multicellular tissue. AP conduction is the outcome of complex interactions between cellular electrical activity, electrical cell-to-cell communication, and the cardiac tissue structure. As shown in this review, strong interactions occur among these determinants of electrical impulse propagation. A special form of conduction that underlies many cardiac arrhythmias involves circulating excitation. In this situation, the curvature of the propagating excitation wavefront and the interaction of the wavefront with the repolarization tail of the preceding wave are additional important determinants of impulse propagation. This review attempts to synthesize results from computer simulations and experimental preparations to define mechanisms and biophysical principles that govern normal and abnormal conduction in the heart.

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