DYNAMICAL EFFECTS OF MYOCARDIAL ISCHEMIA IN ANISOTROPIC CARDIAC MODELS IN THREE DIMENSIONS

The interaction between the presence of moderate or severe subendocardial ischemic regions and the anisotropic structure of the cardiac muscle is investigated here by means of numerical simulations based on anisotropic Bidomain and Monodomain models. The ischemic effects on cardiac excitation, recovery and distribution of action potential duration are discussed, showing the presence of ischemic epicardial markers. Extracellular potential distributions during the ST and TQ intervals are computed separately using non-stationary models. During the ST interval, the extracellular potential patterns differ from those simulated with stationary models used in the literature. These differences are explained by decomposing the cardiac current sources into conormal, axial and orthogonal components and by determining which component is dominant during the ST and TQ intervals.

[1]  N. Trayanova,et al.  Effect of acute global ischemia on the upper limit of vulnerability: a simulation study. , 2004, American journal of physiology. Heart and circulatory physiology.

[2]  P. C. Franzone,et al.  A PARALLEL SOLVER FOR REACTION-DIFFUSION SYSTEMS IN COMPUTATIONAL ELECTROCARDIOLOGY , 2004 .

[3]  A. M. Scher,et al.  Mechanism of S‐T Segment Alteration During Acute Myocardial Injury , 1960, Circulation research.

[4]  B E Sobel,et al.  Distribution of myocardial injury and its relation to epicardial ST-segment changes after coronary artery occlusion in the dog. , 1972, Cardiovascular research.

[5]  C. Henriquez,et al.  Anisotropy, Fiber Curvature, and Bath Loading Effects on Activation in Thin and Thick Cardiac Tissue Preparations: , 1996, Journal of cardiovascular electrophysiology.

[6]  B. Taccardi,et al.  Effects of transmural electrical heterogeneities and electrotonic interactions on the dispersion of cardiac repolarization and action potential duration: A simulation study. , 2006, Mathematical biosciences.

[7]  Denis Noble,et al.  Models of cardiac ventricular action potentials: iterative interaction between experiment and simulation , 2001, Philosophical Transactions of the Royal Society of London. Series A: Mathematical, Physical and Engineering Sciences.

[8]  J. Keener,et al.  Direct activation and defibrillation of cardiac tissue. , 1996, Journal of theoretical biology.

[9]  B. Taccardi,et al.  Spread of excitation in 3-D models of the anisotropic cardiac tissue. III. Effects of ventricular geometry and fiber structure on the potential distribution. , 1997, Mathematical biosciences.

[10]  G. E. Newman,et al.  Significance of subendocardial S-T segment elevation caused by coronary stenosis in the dog. Epicardial S-T segment depression, local ischemia and subsequent necrosis. , 1977, The American journal of cardiology.

[11]  E. Carmeliet.  Cardiac ionic currents and acute ischemia: from channels to arrhythmias. , 1999, Physiological reviews.

[12]  Joakim Sundnes,et al.  Simulation of ST segment changes during subendocardial ischemia using a realistic 3-D cardiac geometry , 2005, IEEE Transactions on Biomedical Engineering.

[13]  D Durrer,et al.  Mechanism and Time Course of S‐T and T‐Q Segment Changes during Acute Regional Myocardial Ischemia in the Pig Heart Determined by Extracellular and Intracellular Recordings , 1978, Circulation research.

[14]  Y. Rudy,et al.  Electrophysiologic effects of acute myocardial ischemia: a theoretical study of altered cell excitability and action potential duration. , 1997, Cardiovascular research.

[15]  D B Geselowitz,et al.  Computation of Heart Surface Potentials Using the Surface Source Model , 1995, Journal of cardiovascular electrophysiology.

[16]  Aoxiang Xu,et al.  Two forms of spiral-wave reentry in an ionic model of ischemic ventricular myocardium. , 1998, Chaos.

[17]  R. Macleod,et al.  The role of heart rate in myocardial ischemia from restricted coronary perfusion. , 2001, Journal of electrocardiology.

[18]  S. Bellet,et al.  Negative displacement of the RS-T segment in the electrocardiogram and its relationship to positive displacement; an experimental study. , 1945, Archivos del Instituto de Cardiologia de Mexico.

[19]  M J Janse,et al.  ST segment mapping and infarct size. , 2000, Cardiovascular research.

[20]  R. Lux,et al.  Effect of Myocardial Fiber Direction on Epicardial Potentials , 1994, Circulation.

[21]  Peter R. Johnston,et al.  The importance of anisotropy in modeling ST segment shift in subendocardial ischaemia , 2001, IEEE Transactions on Biomedical Engineering.

[22]  Y Rudy,et al.  Action potential and contractility changes in [Na(+)](i) overloaded cardiac myocytes: a simulation study. , 2000, Biophysical journal.

[23]  A. Quarteroni,et al.  Numerical Approximation of Partial Differential Equations , 2008 .

[24]  R. Holland,et al.  Precordial and Epicardial Surface Potentials during Myocardial Ischemia in the Pig: A THEORETICAL AND EXPERIMENTAL ANALYSIS OF THE TQ AND ST SEGMENTS , 1975, Circulation research.

[25]  T. Johnson,et al.  Failure of Impulse Propagation in a Mathematically Simulated Ischemic Border Zone: Influence of Direction of Propagation and Cell‐to‐Cell Electrical Coupling , 1995, Journal of cardiovascular electrophysiology.

[26]  Peter R. Johnston,et al.  The effect of conductivity values on ST segment shift in subendocardial ischaemia , 2003, IEEE Transactions on Biomedical Engineering.

[27]  M. Prinzmetal,et al.  Myocardial ischemia. Nature of ischemic electrocardiographic patterns in the mammalian ventricles as determined by intracellular electrographic and metabolic changes. , 1961, The American journal of cardiology.

[28]  A. Kleber.  ST-segment elevation in the electrocardiogram: a sign of myocardial ischemia. , 2000, Cardiovascular research.

[29]  P. C. Franzone,et al.  Spreading of excitation in 3-D models of the anisotropic cardiac tissue. I. Validation of the eikonal model. , 1993, Mathematical biosciences.

[30]  D Kilpatrick,et al.  Epicardial ST depression in acute myocardial infarction. , 1999, Circulation research.

[31]  Alfio Quarteroni,et al.  Complex Systems in Biomedicine , 2006 .

[32]  Giuseppe Savaré,et al.  Degenerate Evolution Systems Modeling the Cardiac Electric Field at Micro- and Macroscopic Level , 2002 .

[33]  P. Hunter,et al.  Laminar structure of the heart: ventricular myocyte arrangement and connective tissue architecture in the dog. , 1995, The American journal of physiology.

[34]  L. Guerri,et al.  ACCURATE COMPUTATION OF ELECTROGRAMS IN THE LEFT VENTRICULAR WALL , 2000 .

[35]  J. Nenonen,et al.  Activation Dynamics in Anisotropic Cardiac Tissue via Decoupling , 2004, Annals of Biomedical Engineering.

[36]  C. Luo,et al.  A model of the ventricular cardiac action potential. Depolarization, repolarization, and their interaction. , 1991, Circulation research.