Skip to main content

Results

  • Chapter
  • First Online:
Complex Structure and Dynamics of the Heart

Part of the book series: Springer Theses ((Springer Theses))

  • 922 Accesses

Abstract

As indicated in the introduction, in this section, the generic view of cardiac tissue as an excitable medium is adopted to investigate how activation patterns in these systems can be characterized. While the approach chosen here is purely theoretical, in the long run, such characterization might aid the quantitative assessment of the turbulence and complexity of cardiac arrhythmias in an experimental situation and thus contribute to the development of adaptive control strategies which make use of this information.

This is a preview of subscription content, log in via an institution to check access.

Access this chapter

Chapter
USD 29.95
Price excludes VAT (USA)
  • Available as PDF
  • Read on any device
  • Instant download
  • Own it forever
eBook
USD 109.00
Price excludes VAT (USA)
  • Available as EPUB and PDF
  • Read on any device
  • Instant download
  • Own it forever
Hardcover Book
USD 139.99
Price excludes VAT (USA)
  • Durable hardcover edition
  • Dispatched in 3 to 5 business days
  • Free shipping worldwide - see info

Tax calculation will be finalised at checkout

Purchases are for personal use only

Institutional subscriptions

Notes

  1. 1.

    If diffusion only acts on the variable \(u\) as in the original model, \(\frac{\partial ^{2} }{\partial y^{2}}\) would correspondingly only act on the \(\delta u\)-component of \(\delta \mathbf {U}\), which would lead to a different \(\mathbf {L}\) and would invalidate the following argument.

  2. 2.

    This protection is caused by the waves that are periodically emitted outwards and prevent any interaction in the opposite direction. Indeed, there is a very weak electrotonic coupling even in retrograde direction which decays exponentially with distance from the boundary, thus quickly vanishing from the accessible range of numerical accuracy.

  3. 3.

    Linear stability analysis can therefore be used to determine the modes that are responsible for instabilities, e.g. meandering and alternans modes for a rigidly rotating spiral in the unstable regime [14, 16].

  4. 4.

    One could also imagine that the spiral wave is just attracted initially by the heterogeneity but its exact position is still arbitrary, which would result in a preservation of the local symmetry.

  5. 5.

    It should be emphasized that the number of phase singularities which are detected depends on the chosen origin \((u^*,v^*)\) necessary to define the phase. Although visual inspection of the dynamics for the parameters considered in this section confirms that the detected phase singularities are reasonable, the numbers can deviate from those reported in Ref. [25].

  6. 6.

    Infinitesimal deviation \(\delta \mathbf {u}\) from the resting state and infinitesimal electric fields are equivalent assumptions, as the resting state is known to be stable.

  7. 7.

    Equation (3.16) is identical to the ad-hoc ansatz used in Refs. [28, 31] to assess electric-field induced membrane potential changes for circular obstacles. However, those publications use a different sign in Eq. (3.16b). Private communication with the main author, Alain Pumir, led to the finding that the latter is a misprint.

  8. 8.

    The size and curvature of the tissue domains can be normalized by \(\lambda \), as explained in Sect. 3.2.3. Therefore, the actual parameters used for the Fenton-Karma model do not alter the results. The only condition is that the field strength used is small enough to preserve the validity of Eq. (3.16a, 3.16b).

  9. 9.

    As \(\mathbf {E}\) has units of a potential divided by a length, applying the same transformations as for \(\mathbf {x}\) and \(e\) automatically leads to a unit \(\mathbf {E}^*\), thus being identical to \({\hat{\mathbf {E}}}\) defined above.

  10. 10.

    In fact, for the infinite stack, i.e. \(I=\mathbb R\), the electric field can also have a \(z\)-component, which does, however, not change the solution, because all normal vectors have vanishing \(z\)-components according to Eq. (3.22)

  11. 11.

    As very small domains are equivalent to very large \(\lambda \) (cf. Sect. 3.2.4), this is also clear directly from Eq. (3.16a), which turns into a homogeneous Laplace equation for large \(\lambda \).

  12. 12.

    As indicated in Sect. 2.1.3, the assumption of a constant electric field vector determining the boundary condition of Eq. (3.16b) and ultimately the \(\cos \)-term on the right hand side of Eq. (3.29) is only an approximation. In case a more realistic boundary condition is determined in the future and the right hand side of Eq. (3.29) is replaced with some arbitrary function \(f(\varphi )\), the mathematical strategy as presented here could be applied by writing \(f\) as a sum of its Fourier modes \(a_n\cos (n\varphi )\), \(b_n\sin (n\varphi )\). With the ansatz \(e^*_{a,b}=cg(r^*)\cos (n\varphi )\) (or similarly with \(\sin \)), following the derivation would lead to solutions involving \(K_n\) and \(I_n\), where \(n=1\) is only the special case considered above. As the Neumann boundary condition of Eq. (3.29) is additive, the solution could then be written as a sum of these partial solutions.

  13. 13.

    Note that, despite the adaptive space step \(h\) of the simulations, the numerical realization of the boundaries using the phase-field method slightly underestimates the electric field-induced effect in the asymptotic case (see Fig. 3.27). Assuming this trend holds for finite pulse duration, the critical field strength in the corresponding field strength range shown in Fig. 3.35 could be slightly too high.

  14. 14.

    See also Ref. [46] and references therein.

  15. 15.

    One bin containing all sizes of blood vessels beyond the upper limit of the plotting range in Figs. 3.44a and 3.43a was included in the prediction. This corresponds to blood that are large enough to be activated already at the lowest predicted field strengths.

References

  1. Karma, A. (2013). Physics of cardiac arrhythmogenesis. Annual Review of Condensed Matter Physics, 4, 313–337.

    Article  ADS  Google Scholar 

  2. Ginelli, F., et al. (2007). Characterizing dynamics with covariant Lyapunov vectors. Physical Review Letters, 99, 130601.

    Article  ADS  Google Scholar 

  3. Bochi, J., & Viana, M. (2005). The Lyapunov exponents of generic volume-preserving and symplectic maps. Annals of Mathematics, 161, 1423–1485.

    Article  MATH  MathSciNet  Google Scholar 

  4. Pugh, C., Shub, M., & Starkov, A. (2004). Stable ergodicity. Bulletin of the American Mathematical Society, 41, 1–41.

    Article  MATH  MathSciNet  Google Scholar 

  5. Yang, H., Takeuchi, K. A., Ginelli, F., Chate, H., & Radons, G. (2009). Hyperbolicity and the effective dimension of spatially extended dissipative systems. Physical Review Letters, 102, 074102.

    Article  ADS  Google Scholar 

  6. Heagy, J., Carroll, T., & Pecora, L. (1994). Synchronous chaos in coupled oscillator systems. Physical Review E, 50, 1874–1885.

    Article  ADS  Google Scholar 

  7. Fenton, F. H., Cherry, E. M., Hastings, H., & Evans, S. (2002). Multiple mechanisms of spiral wave breakup in a model of cardiac electrical activity. Chaos, 12, 852–892.

    Article  ADS  Google Scholar 

  8. Panfilov, A. V., & Keener, J. (1995). Re-entry in three-dimensional FitzHugh-Nagumo medium with rotational anisotropy. Physica D, 84, 545–552.

    Article  ADS  Google Scholar 

  9. Panfilov, A. V. (2002). Spiral breakup in an array of coupled cells: The role of the intercellular conductance. Physical Review Letters, 88, 118101.

    Article  ADS  Google Scholar 

  10. Bueno-Orovio, A., Cherry, E. M., & Fenton, F. H. (2008). Minimal model for human ventricular action potentials in tissue. Journal of Theoretical Biology, 253, 544–560.

    Article  MathSciNet  Google Scholar 

  11. Clayton, R. H., et al. (2011). Models of cardiac tissue electrophysiology: Progress, challenges and open questions. Progress in Biophysics and Molecular Biology, 104, 22–48.

    Article  Google Scholar 

  12. Otani, N. F., et al. (2008). Characterization of multiple spiral wave dynamics as a stochastic predator-prey system. Physical Review E, 78, 021913.

    Article  ADS  MathSciNet  Google Scholar 

  13. Barkley, D., Kness, M., & Tuckerman, L. (1990). Spiral-wave dynamics in a simple model of excitable media: The transition from simple to compound rotation. Physical Review A, 42, 2489–2492.

    Article  ADS  MathSciNet  Google Scholar 

  14. Barkley, D. (1994). Euclidean symmetry and the dynamics of rotating spiral waves. Physical Review Letters, 72, 164–167.

    Article  ADS  Google Scholar 

  15. Barkley, D. (1992). Linear stability analysis of rotating spiral waves in excitable media. Physical Review Letters, 68, 2090–2093.

    Article  ADS  Google Scholar 

  16. Allexandre, D., & Otani, N. F. (2004). Preventing alternans-induced spiral wave breakup in cardiac tissue: An ion-channel-based approach. Physical Review E, 70, 061903.

    Article  ADS  Google Scholar 

  17. Panfilov, A. V., & Vasiev, B. (1991). Vortex initiation in a heterogeneous excitable medium. Physica D, 49, 107–113.

    Article  ADS  Google Scholar 

  18. Sadeghi, P., & Rotermund, H. H. (2011). Gradient induced spiral drift in heterogeneous excitable media. Chaos, 21, 013125.

    Article  ADS  Google Scholar 

  19. ten Tusscher, K. H. W. J., & Panfilov, A. V. (2003). Reentry in heterogeneous cardiac tissue described by the Luo-Rudy ventricular action potential model. American Journal of Physiology: Heart and Circulatory Physiology, 284, H542–H548.

    Google Scholar 

  20. Sridhar, S., Sinha, S., & Panfilov, A. V. (2010). Anomalous drift of spiral waves in heterogeneous excitable media. Physical Review E, 82, 051908.

    Article  ADS  Google Scholar 

  21. Biktasheva, I. V., Holden, A. V., & Biktashev, V. N. (2006). Localization of response functions of spiral waves in the FitzHugh-Nagumo system. International Journal of Bifurcation and Chaos, 16, 1547–1555.

    Article  MATH  MathSciNet  Google Scholar 

  22. Biktasheva, I. V., Barkley, D., Biktashev, V. N., & Foulkes, A. J. (2010). Computation of the drift velocity of spiral waves using response functions. Physical Review E, 81, 066202.

    Article  ADS  MathSciNet  Google Scholar 

  23. Kaplan, J. L., & Yorke, J. A. (1979). Chaotic behavior of multidimensional difference equations. In H. O. Peitgen & H. O. Walther (Eds.), Functional differential equations and approximations of fixed points. Lecture notes in Mathematics (Vol. 730, p. 204). Berlin: Springer.

    Google Scholar 

  24. Rényi, A. (1959). On the dimension and entropy of probability distributions. Acta Mathematica Academiae Scientiarum Hungarica, 10, 193–215.

    Article  MATH  Google Scholar 

  25. Strain, M., & Greenside, H. (1998). Size-dependent transition to high-dimensional chaotic dynamics in a two-dimensional excitable medium. Physical Review Letters, 80, 2306–2309.

    Article  ADS  Google Scholar 

  26. Bär, M., & Eiswirth, M. (1993). Turbulence due to spiral breakup in a continuous excitable medium. Physical Review E, 48, R1635–R1637.

    Article  ADS  Google Scholar 

  27. Bittihn, P., Hörning, M., & Luther, S. (2012). Negative curvature boundaries as wave emitting sites for the control of biological excitable media. Physical Review Letters, 109, 118106.

    Article  ADS  Google Scholar 

  28. Pumir, A., & Krinsky, V. I. (1999). Unpinning of a rotating wave in cardiac muscle by an electric field. Journal of Theoretical Biology, 199, 311–319.

    Article  Google Scholar 

  29. Takagi, S., et al. (2004). A physical approach to remove anatomical reentries: A bidomain study. Journal of Theoretical Biology, 230, 489–497.

    Article  MathSciNet  Google Scholar 

  30. Takagi, S., et al. (2004). Unpinning and removal of a rotating wave in cardiac muscle. Physical Review Letters, 93, 058101.

    Article  ADS  Google Scholar 

  31. Pumir, A., et al. (2007). Wave emission from heterogeneities opens a way to controlling chaos in the heart. Physical Review Letters, 99, 208101.

    Article  ADS  Google Scholar 

  32. Bittihn, P., et al. (2008). Far field pacing supersedes anti-tachycardia pacing in a generic model of excitable media. New Journal of Physics, 10, 103012.

    Article  ADS  Google Scholar 

  33. Bittihn, P. (2009). Control of spiral wave activity in excitable media (Diploma thesis, University of Göttingen, 2009).

    Google Scholar 

  34. Fenton, F. H., et al. (2009). Termination of atrial fibrillation using pulsed low-energy far-field stimulation. Circulation, 120, 467–474.

    Article  Google Scholar 

  35. Luther, S., et al. (2011). Low-energy control of electrical turbulence in the heart. Nature, 475, 235–239.

    Article  ADS  Google Scholar 

  36. Trayanova, N., Skouibine, K., & Aguel, F. (1998). The role of cardiac tissue structure in defibrillation. Chaos, 8, 221–233.

    Article  ADS  Google Scholar 

  37. Trayanova, N., & Skouibine, K. (1998). Modeling defibrillation: Effects of fiber curvature. Journal of Electrocardiology, 31, 23–29.

    Article  Google Scholar 

  38. Entcheva, E., et al. (1998). Virtual electrode effects in transvenous defibrillation-modulation by structure and interface: Evidence from bidomain simulations and optical mapping. Journal of Cardiovascular Electrophysiology, 9, 949–961.

    Article  Google Scholar 

  39. Kondratyev, A. A. et al. (2012). Virtual sources and sinks during extracellular field shocks in cardiac cell cultures: Effects of source-sink interactions between adjacent tissue boundaries. Circulation: Arrhythmia and Electrophysiology, 5, 391–399.

    Google Scholar 

  40. Stegun, I., & Abramowitz, M. (Eds.). (1964). Handbook of mathematical functions with formulas, graphs, and mathematical tables. National Bureau of Standards, Applied Mathematics Series 55. Retrieved December 1972, from http://people.math.sfu.ca/~cbm/aands/ (tenth printing).

  41. Fast, V., & Kleber, A. (1997). Role of wavefront curvature in propagation of cardiac impulse. Cardiovascular Research, 33, 258–271.

    Article  Google Scholar 

  42. Schröder-Schetelig, J. (2012). Experimentelle und theoretische Charakterisierung der Erregungsausbreitung im Kaninchenherzen anhand von Restitutionskurven (Diploma thesis, University of Göttingen, 2012).

    Google Scholar 

  43. Zhou, Y., Kassab, G. S., & Molloi, S. (1999). On the design of the coronary arterial tree: A generalization of murray’s law. Physics in Medicine and Biology, 44, 2929–2945.

    Article  ADS  Google Scholar 

  44. Kassab, G. S. (2006). Scaling laws of vascular trees: Of form and function. American Journal of Physiology: Heart and Circulatory Physiology, 290, H894–H903.

    Google Scholar 

  45. Huo, Y., & Kassab, G. S. (2009). A scaling law of vascular volume. Biophysical Journal, 96, 347–353.

    Article  ADS  Google Scholar 

  46. Santamore, W. P., & Bove, A. A. (2008). Why are arteries the size they are? Journal of Applied Physiology, 104, 1259.

    Article  Google Scholar 

  47. Hornung, D. (2013). Cardiac arrhythmia termination on the vascular and organ scale (Ph.D. thesis, University of Göttingen, 2013).

    Google Scholar 

  48. Hyatt, C., Mironov, S., Vetter, F., Zemlin, C., & Pertsov, A. (2005). Optical action potential upstroke morphology reveals near-surface transmural propagation direction. Circulation Research, 97, 277–284.

    Article  Google Scholar 

  49. Jenkins, M. (2008). Imaging the embryonic heart with optical coherence tomography (Ph.D. thesis, Case Western Reserve University, 2008).

    Google Scholar 

  50. Mitrea, B. G., Caldwell, B. J., & Pertsov, A. M. (2011). Imaging electrical excitation inside the myocardial wall. Biomedical Optics Express, 2, 620–633.

    Article  Google Scholar 

  51. Provost, J., Gambhir, A., Vest, J., Garan, H., & Konofagou, E. E. (2013). A clinical feasibility study of atrial and ventricular electromechanical wave imaging. Heart Rhythm, 10, 856–862.

    Article  Google Scholar 

  52. Veteĭkis, R., Grigaliunas, A., & Mutskus, K. (2001). Comparative study of the space constant of electrotonic decay in the endocardium and epicardium of the rabbit right atrium. Biofizika, 46, 310–314.

    Google Scholar 

  53. Koster, R. et al. (2004). A randomized trial comparing monophasic and biphasic waveform shocks for external cardioversion of atrial fibrillation. American Heart Journal, 147, 828.e1–828.e7.

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Philip Bittihn .

Rights and permissions

Reprints and permissions

Copyright information

© 2015 Springer International Publishing Switzerland

About this chapter

Cite this chapter

Bittihn, P. (2015). Results. In: Complex Structure and Dynamics of the Heart. Springer Theses. Springer, Cham. https://doi.org/10.1007/978-3-319-12232-8_3

Download citation

Publish with us

Policies and ethics