Abstract
The major determinants of the T wave polarity in electrocardiograms (ECGs) are still a debated issue. The aim of this work is to investigate the effects of tissue anisotropy, cellular action potential duration (APD) heterogeneities and excitation wavefront shape on the T wave polarity in unipolar and bipolar ECGs, simulated in a conducting medium surrounding the cardiac tissue at some distance fom endo to epicardium. The study is based on three-dimensional anisotropic Monodomain simulations of the entire depolarization and repolarization phases of propagating action potentials in a parallelepipedal slab. The results show that the T wave of unipolar ECGs is positive at all sites explored and its shape and polarity are mainly determined by the anisotropy of the cardiac tissue, irrespective of cellular APD heterogeneities and shape of the excitation wavefront. On the other hand, bipolar ECGs are mainly affected by their isotropic component and their T wave turns out to be positive for single site stimulations in the presence of transmural APD heterogeneity, while it becomes always negative in case of multiple sites stimulation generating large activation wavefronts, regardless of the considered cellular APD heterogeneities.
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References
di Bernardo, D., Murray, A.: Computer model for study of cardiac repolarization. J. Cardiovasc. Electrophys. 11(8), 895–899 (2000)
Boulakia, M., et al.: Towards the Numerical Simulation of Electrocardiograms. In: Sachse, F.B., Seemann, G. (eds.) FIMH 2007. LNCS, vol. 4466, pp. 240–249. Springer, Heidelberg (2007)
Clements, J.C., et al.: Activation Dynamics in Anisotropic Cardiac Tissue via Decoupling. Ann. Biomed. Engrg. 32(7), 984–990 (2004)
Colli Franzone, P., et al.: On the polyphasic character of simulated and experimental electrograms. Biomedizin. Tech. 46(2), 16–19 (2001)
Colli Franzone, P., et al.: Anisotropic mechanism for multiphasic unipolar electrograms. Simulation studies and experimental recordings. Ann. Biomed. Engrg. 28, 1–17 (2000)
Colli Franzone, P., et al.: Simulating patterns of excitation, repolarization and action potential duration with cardiac bidomain and monodomain models. Math. Biosci. 197(1), 35–66 (2005)
Colli Franzone, P., et al.: Effects of transmural electrical heterogeneities and electrotonic interactions on the dispersion of cardiac repolarization and action potential duration: A simulation study. Math. Biosci. 204(1), 132–165 (2006)
Clayton, R.H., Holden, A.V.: Propagation of normal beats and re-entry in a computational model of ventricular cardiac tissue with regional differences in action potential shape and duration. Progr. Biophys. Mol. Biol. 85(2–3), 473–499 (2004)
Conrath, C.E., Opthof, T.: Ventricular repolarization: An overview of (patho)physiology, sympathetic effects and genetic aspects. Progr. Biophys. Mol. Biol. 92(3), 269–307 (2006)
Fish, J.M., et al.: Epicardial activation of left ventricular wall prolongs QT interval and transmural dispersion of repolarization - Implications for biventricular pacing. Circulation 109(17), 2136–2142 (2004)
Franz, M.R., et al.: Monophasic action potential mapping in human subjects with normal electrocardiograms: direct evidence for the genesis of the T wave. Circulation 75, 379–386 (1987)
Gima, K., Rudy, Y.: Ionic current basis of electrocardiographic waveforms: A model study. Circ. Res. 90, 889–896 (2002)
Huiskamp, G.: Simulation of depolarization in a membrane-equation-based model of the anisotropic ventricle. IEEE Trans. Biomed. Engrg. 45, 847–855 (1998)
Janse, M., et al.: Repolarization gradients in the canine left ventricle before and after induction of short-term cardiac memory. Circulation 112, 1711–1718 (2005)
Leon, L.J., Horacek, B.M.: Computer model of excitation and recovery in the anisotropic myocardium. I. Rectangular and cubic arrays of excitable elements. J. Electrocardiol. 24(1), 1–15 (1991)
Luo, C., Rudy, Y.: A model of the ventricular cardiac action potential: depolarization, repolarization, and their interaction. Circ. Res. 68, 1501–1526 (1991)
Simms Jr., H.D., Geselowitz, D.B.: Computation of Heart Surface Potentials Using the Surface Source Model. J. Cardiovasc. Electrophys. 6(7), 522–531 (1995)
Taggart, P., et al.: Transmural repolarization in the left ventricle in humans during normoxia and ischaemia. Cardiovasc. Rer. 50(3), 454–462 (2001)
van Oosterom, A.: Genesis of the T wave as based on an equivalent surface source model. J. Electrocard. 34, 217–227 (2001)
Weiss, D.L., et al.: Modeling of heterogeneous electrophysiology in the human heart with respect of ECG genesis. Proceed. Comput. in Cardiol. 34, 49–52 (2007)
Yan, G.-X., Antzelevitch, C.: Cellular basis for the normal T wave and the electrocardiographic manifestations of the Long-QT syndrome. Circulation 98, 1928–1936 (1998)
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Colli Franzone, P., Pavarino, L.F., Scacchi, S., Taccardi, B. (2009). Effects of Anisotropy and Transmural Heterogeneity on the T-Wave Polarity of Simulated Electrograms. In: Ayache, N., Delingette, H., Sermesant, M. (eds) Functional Imaging and Modeling of the Heart. FIMH 2009. Lecture Notes in Computer Science, vol 5528. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-01932-6_55
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DOI: https://doi.org/10.1007/978-3-642-01932-6_55
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