Mechanisms of Isolated Cell Stimulation

  • Vinod Sharma

It is a common practice in several fields of modern science to reduce a complex system to its simplest unit to gain fundamental insights into phenomena of interest. Field stimulation of cardiac cell is no different. Understanding the effects of an electrical shock at the simplest unit of cardiac tissue, an isolated cardiac cell, can lend valuable insights into mechanisms of field stimulation, especially those involved in phenomena such as fibrillation and defibrillation. These mechanisms have remained largely unresolved despite defibrillation having been applied clinically for over 60 years1 and become the mainstay of clinical medicine with the advent of implantable cardioverter-defibrillators (ICDs)2–4 and automatic external defibrillators (AED).5 Taking a reductionism approach, this chapter discusses the field-induced responses of single cardiac cells to electric field stimulation. Transmembrane voltage (V m) is widely acknowledged as the most important parameter during electric field stimulation of cardiac tissue, and hence we spend a significant portion of the chapter discussing the interaction between an externally applied field and isolated cell. Building on this we then discuss a slightly more complex system of a cell-pair. A coupled cell-pair is the simplest system in which the effects of intercellular gap junction on field-induced V m responses can be studied. Finally, we briefly discuss the effects of externally applied fields on intracellular Ca2+ dynamics since Ca2+is intimately linked to V m via voltage-dependent responsiveness of L-type Ca2+ channels.

New Therapies and Diagnostics, Medtronic, Inc., 8200 Coral Sea Street N.E., Minneapolis, MN 55112, USA,


Cardiac Cell Cell Length Action Potential Amplitude Virtual Source Negative Drift 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Beck CS. Resuscitation for cardiac standstill and ventricular fibrillation occurring during operation.Am J Surg1941;54:273–279CrossRefGoogle Scholar
  2. 2.
    Cesario DA, Dec GW. Implantable cardioverter-defibrillator therapy in clinical practice.J Am Coll Cardiol2006;47:1507–1517PubMedCrossRefGoogle Scholar
  3. 3.
    DiMarco JP. Implantable cardioverter-defibrillators.N Engl J Med2003;349:1836–1847PubMedCrossRefGoogle Scholar
  4. 4.
    Goldberger Z, Lampert R. Implantable cardioverter-defibrillators: expanding indications and technologies.JAMA2006;295:809–818PubMedCrossRefGoogle Scholar
  5. 5.
    Marenco JP, Wang PJ, Link MS, Homoud MK, Estes NA III. Improving survival from sudden cardiac arrest: the role of the automated external defibrillator.JAMA2001;285:1193–1200PubMedCrossRefGoogle Scholar
  6. 6.
    Klee M, Plonsey R. Stimulation of spheroidal cells — the role of cell shape.IEEE Trans Biomed Eng1976;23:347–354PubMedCrossRefGoogle Scholar
  7. 7.
    Jeltsch E, Zimmerman U. Particles in a homogeneous field: a model for the electrical breakdown of living cells in a Coulter counter.Bioelectrochem Bioenerg1979;6:349–384CrossRefGoogle Scholar
  8. 8.
    Gross D, Loew LM, Webb WW. Optical imaging of cell membrane potential changes induced by applied electric fields.Biophys J1986;50:339–348PubMedGoogle Scholar
  9. 9.
    Hibino M, Shigemori M, Itoh H, Nagayama K, Kinosita K Jr. Membrane conductance of an electroporated cell analyzed by submicrosecond imaging of transmembrane potential.Biophys J1991;59:209–220PubMedGoogle Scholar
  10. 10.
    Ehrenberg B, Farkas DL, Fluhler EN, Lojewska Z, Loew LM. Membrane potential induced by external electric field pulses can be followed with a potentiomet-ric dye.Biophys J1987;51:833–837 [published erratum appears inBiophys. J1987 Jul;52(1):following 141]PubMedCrossRefGoogle Scholar
  11. 11.
    Kwaku KF, Dillon SM. Shock-induced depolarization of refractory myocardium prevents wave-front propagation in defibrillation.Circ Res1996;79:957–973PubMedGoogle Scholar
  12. 12.
    Watanabe T, Rautaharju PM, McDonald TF. Ventricular action potentials, ventricular extracellular potentials, and the ECG of guinea pig.Circ Res1985;57:362–373PubMedGoogle Scholar
  13. 13.
    Cheng DKL, Tung L, Sobie EA. Nonuniform responses of transmembrane potential during electric field stimulation of single cardiac cells.Am J Physiol1999;277 (Heart Circ Physiol46):H351–H362Google Scholar
  14. 14.
    Knisley SB, Blitchington TF, Hill BC, Grant AO, Smith WM, Pilkington TC, Ideker RE. Optical measurements of transmembrane potential changes during electric field stimulation of ventricular cells.Circ Res1993;72:255–270PubMedGoogle Scholar
  15. 15.
    Windisch H, Ahammer H, Schaffer P, Muller W, Platzer D. Optical multisite monitoring of cell excitation phenomena in isolated cardiomyocytes.Pflugers Arch1995;430:508–518PubMedCrossRefGoogle Scholar
  16. 16.
    Sharma V, Tung L. Spatial heterogeneity of transmembrane potential responses of single guinea-pig cardiac cells during electric field stimulation.J Physiol2002;542:477–492PubMedCrossRefGoogle Scholar
  17. 17.
    Rohr S, Kucera JP. Optical recording system based on a fiber optic image conduit: assessment of microscopic activation patterns in cardiac tissue.Biophys J1998;75:1062– 1075PubMedGoogle Scholar
  18. 18.
    Windisch H, Ahammer H, Schaffer P, Muller W, Platzer D. Optical multisite monitoring of cell excitation phenomena in isolated cardiomyocytes.Pflugers Arch1995;430:508–518PubMedCrossRefGoogle Scholar
  19. 19.
    Sharma V, Susil RC, Tung L. Paradoxical loss of excitation with high intensity pulses during electric field stimulation of single cardiac cells.Biophys J2005;88:3038–3049PubMedCrossRefGoogle Scholar
  20. 20.
    Koning G, Veefkind AH, Schneider H. Cardiac damage caused by direct application of defibrillator shocks to isolated Langendorff-perfused rabbit heart.Am Heart J1980;100:473–482PubMedCrossRefGoogle Scholar
  21. 21.
    O'Neill RJ, Tung L. Cell-attached patch clamp study of the electropermeabilization of amphibian cardiac cells.Biophys J1991;59:1028–1039PubMedGoogle Scholar
  22. 22.
    Luo CH, Rudy Y. A model of the ventricular cardiac action potential. Depolarization, repolarization, and their interaction.Circ Res1991;68:1501–1526PubMedGoogle Scholar
  23. 23.
    Puglisi JL, Wang F, Bers DM. Modeling the isolated cardiac myocyte.Prog Biophys Mol Biol2004;85:163–178PubMedCrossRefGoogle Scholar
  24. 24.
    Tung L, Borderies JR. Analysis of electric field stimulation of single cardiac muscle cells.Biophys J1992;63:371–386PubMedGoogle Scholar
  25. 25.
    Sharma V, Lu SN, Tung L. Decomposition of field-induced transmembrane potential responses of single cardiac cells.IEEE Trans Biomed Eng2002;49:1031–1037PubMedCrossRefGoogle Scholar
  26. 26.
    Sharma V, Tung L. Transmembrane responses of single guinea pig ventricular cell to uniform electric field stimulus.J Cardiovasc Electrophysiol1999;10:1296PubMedCrossRefGoogle Scholar
  27. 27.
    Luo CH, Rudy Y. A dynamic model of the cardiac ventricular action potential. I. Simulations of ionic currents and concentration changes.Circ Res1994;74:1071–1096PubMedGoogle Scholar
  28. 28.
    Zeng J, Laurita KR, Rosenbaum DS, Rudy Y. Two components of the delayed rectifier K+ current in ventricular myocytes of the guinea pig type. Theoretical formulation and their role in repolarization.Circ Res1995;77:140–152PubMedGoogle Scholar
  29. 29.
    Sharma V, Tung L. Ionic currents involved in shock-induced nonlinear changes in transmembrane potential responses of single cardiac cells.Pflugers Arch2004;449:248– 256PubMedGoogle Scholar
  30. 30.
    Cheek ER, Ideker RE, Fast VG. Nonlinear changes of transmembrane potential during defibrillation shocks: role of Ca2+current.Circ Res2000;87:453–459PubMedGoogle Scholar
  31. 31.
    Ashihara T, Trayanova NA. Cell and tissue responses to electric shocks.Europace 2005;7:155–165PubMedCrossRefGoogle Scholar
  32. 32.
    Neunlist M, Tung L. Optical recordings of ventricular excitability of frog heart by an extracellular stimulating point electrode.Pacing Clin Electrophysiol1994;17:1641–1654PubMedCrossRefGoogle Scholar
  33. 33.
    Tung L, Neunlist M, Sobie EA. Near-field and far-field stimulation of cardiac muscle.Clin Appl Mod Imaging Technol II1994;2132:367–374Google Scholar
  34. 34.
    Neunlist M, Tung L. Spatial distribution of cardiac transmembrane potentials around an extracellular electrode: dependence on fiber orientation.Biophys J1995;68:2310–2322PubMedGoogle Scholar
  35. 35.
    Gillis AM, Fast VG, Rohr S, Kleber AG. Spatial changes in transmembrane potential during extracellular electrical shocks in cultured monolayers of neonatal rat ventricular myocytes.Circ Res1996;79:676–690PubMedGoogle Scholar
  36. 36.
    Zhou X, Knisley SB, Smith WM, Rollins D, Pollard AE, Idekar RE. Spatial changes in the transmembrane potential during extracellular electric stimulation.Circ Res1998;83:1003–1014PubMedGoogle Scholar
  37. 37.
    Mowrey KA, Cheng Y, Tchou PJ, Efimov R. Kinetics of defibrillation shock-induced response: design implications for the optimal defibrillation waveform.Europace2002;4:27–39PubMedCrossRefGoogle Scholar
  38. 38.
    Sharma V, Qu F, Nikolski VP, DeGroot P, Efimov IR. Direct measurements of membrane time constant during defibrillation strength shocks.Heart Rhythm2007;4:478–486PubMedCrossRefGoogle Scholar
  39. 39.
    Fast VG, Rohr S, Ideker RE. Nonlinear changes of transmembrane potential caused by defibrillation shocks in strands of cultured myocytes.Am J Physiol Heart Circ Physiol2000;278:H688–H697PubMedGoogle Scholar
  40. 40.
    Susil RC, Sobie EA, Tung L. Separation between virtual sources modifies the response of cardiac tissue to field stimulation.J Cardiovasc Electrophysiol1999;10:715–727PubMedCrossRefGoogle Scholar
  41. 41.
    Tung L, Kleber AG. Virtual sources associated with linear and curved strands of cardiac cells.Am J Physiol Heart Circ Physiol2000;279:H1579–H1590PubMedGoogle Scholar
  42. 42.
    Roth BJ, Krassowska W. The induction of reentry in cardiac tissue. The missing link: how electric fields alter transmembrane potential.Chaos1998;8:204–220PubMedCrossRefGoogle Scholar
  43. 43.
    Dorri F, Niederer PF, Redmann K, Lunkenheimer PP, Cryer CW, Anderson RH. An analysis of the spatial arrangement of the myocardial aggregates making up the wall of the left ventricle.Eur J Cardiothorac Surg2007;31:430–437PubMedCrossRefGoogle Scholar
  44. 44.
    LeGrice IJ, Smaill BH, Chai LZ, Edgar SG, Gavin JB, Hunter PJ. Laminar structure of the heart: ventricular myocyte arrangement and connective tissue architecture in the dog.Am J Physiol1995;269:H571–H582Google Scholar
  45. 45.
    White JB, Walcott GP, Pollard AE, Ideker RE. Myocardial discontinuities: a substrate for producing virtual electrodes that directly excite the myocardium by shocks.Circulation1998;97:1738–1745PubMedGoogle Scholar
  46. 46.
    Makowski L, Caspar DL, Phillips WC, Goodenough DA. Gap junction structures. II. Analysis of the X-ray diffraction data.J Cell Biol1977;74:629–645PubMedCrossRefGoogle Scholar
  47. 47.
    White RL, Spray DC, Campos de Carvalho AC, Wittenberg BA, Bennett MV. Some electrical and pharmacological properties of gap junctions between adult ventricular myocytes.Am J Physiol1985;249:C447–455PubMedGoogle Scholar
  48. 48.
    Weingart R, Maurer P. Action potential transfer in cell pairs isolated from adult rat and guinea pig ventricles.Circ Res1988;63:72–80PubMedGoogle Scholar
  49. 49.
    Kieval RS, Spear JF, Moore EN. Gap junctional conductance in ventricular myocyte pairs isolated from postischemic rabbit myocardium.Circ Res1992;71:127–136PubMedGoogle Scholar
  50. 50.
    Sharma V, Tung L. Theoretical and experimental study of sawtooth effect in isolated cardiac cell-pairs.J Cardiovasc Electrophysiol2001;12:1164–1173PubMedCrossRefGoogle Scholar
  51. 51.
    Plonsey R, Barr RC. Inclusion of junction elements in a linear cardiac model through secondary sources: application to defibrillation.Med Biol Eng Comput1986;24:137–144PubMedCrossRefGoogle Scholar
  52. 52.
    Plonsey R, Barr RC. Effect of junctional resistance on source-strength in a linear cable.Ann Biomed Eng1985;13:95–100PubMedCrossRefGoogle Scholar
  53. 53.
    Plonsey R, Barr RC. Inclusion of junction elements in a linear cardiac model through secondary sources: application to defibrillation.Med Biol Eng Comput1986;24:137–144PubMedCrossRefGoogle Scholar
  54. 54.
    Krinsky V, Pumir A. Models of defibrillation of cardiac tissue.Chaos1988;8:188–203CrossRefGoogle Scholar
  55. 55.
    Juhlin SP, Pormann JB. Dimensional comparison of the sawtooth pattern in transmem-brane potential.Comput Cardiol1994;413–416Google Scholar
  56. 56.
    Wittenberg BA, White RL, Ginzberg RD, Spray DC. Effect of calcium on the dissociation of the mature rat heart into individual and paired myocytes: electrical properties of cell pairs.Circ Res1986;59:143–150PubMedGoogle Scholar
  57. 57.
    Roth BJ. Sawtooth effect: fact or fancy?J Cardiovasc Electrophysiol2001;12:1174–1175PubMedCrossRefGoogle Scholar
  58. 58.
    Knisley SB, Smith WM, Ideker RE. Effect of field stimulation on cellular repolarization in rabbit myocardium. Implications for reentry induction.Circ Res1992;70:707–715PubMedGoogle Scholar
  59. 59.
    Frazier DW, Wolf PD, Wharton JM, Tang AS, Smith WM, Ideker RE. Stimulus-induced critical point. Mechanism for electrical initiation of reentry in normal canine myocardium.J Clin Invest1989;83:1039–1052PubMedCrossRefGoogle Scholar
  60. 60.
    Krassowska W, Kumar MS. The role of spatial interactions in creating the dispersion of transmembrane potential by premature electric shocks.Ann Biomed Eng1997;25:949– 963PubMedGoogle Scholar
  61. 61.
    Ideker RE, Wolf PD, Tang AS.Mechanisms of DefibrillationSt. Louis: Mosby; 1994Google Scholar
  62. 62.
    Trayanova N, Skouibine K, Aguel F. The role of cardiac tissue structure in defibrillation.Chaos1998;8:221–233PubMedCrossRefGoogle Scholar
  63. 63.
    Huang X, Sandusky GE, Zipes DP. Heterogeneous loss of connexin43 protein in ischemia dog hearts.J Cardiovasc Electrophysiol1999;10:79–91PubMedCrossRefGoogle Scholar
  64. 64.
    Gray RA. What exactly are optically recorded “action potentials”?J Cardiovasc Electrophysiol1999;10:1463–1466PubMedCrossRefGoogle Scholar
  65. 65.
    Rubart M. Two-photon microscopy of cells and tissue.Circ Res2004;95:1154–1166PubMedCrossRefGoogle Scholar
  66. 66.
    Rohr S, Scholly DM, Kleber AG. Patterned growth of neonatal rat heart cells in culture. Morphological and electrophysiological characterization.Circ Res1991;68:114–130PubMedGoogle Scholar
  67. 67.
    Berridge MJ, Bootman MD, Lipp P. Calcium — a life and death signal.Nature1998;395:645–648PubMedCrossRefGoogle Scholar
  68. 68.
    Berridge MJ, Lipp P, Bootman MD. The versatility and universality of calcium signalling.Nat Rev Mol Cell Biol2000;1:11–21PubMedCrossRefGoogle Scholar
  69. 69.
    Beuckelmann DJ, Wier WG. Mechanism of release of calcium from sarcoplasmic retic-ulum of guinea- pig cardiac cells.J Physiol (Lond)1988;405:233–255Google Scholar
  70. 70.
    Fabiato A. Simulated calcium current can both cause calcium loading in and trigger calcium release from the sarcoplasmic reticulum of a skinned canine cardiac Purkinje cell.J Gen Physiol1985;85:291–320PubMedCrossRefGoogle Scholar
  71. 71.
    Callewaert G, Cleemann L, Morad M. Epinephrine enhances Ca2+current-regulated Ca2+release and Ca2+reuptake in rat ventricular myocytes.Proc Natl Acad Sci USA. 1988;85:2009–2013PubMedCrossRefGoogle Scholar
  72. 72.
    Santana LF, Cheng H, Gomez AM, Cannell MB, Lederer WJ. Relation between the sarcolemmal Ca2+current and Ca2+sparks and local control theories for cardiac excitation-contraction coupling.Circ Res1996;78:166–171PubMedGoogle Scholar
  73. 73.
    Cannell MB, Berlin JR, Lederer WJ. Effect of membrane potential changes on the calcium transient in single rat cardiac muscle cells.Science1987;238:1419–1423PubMedCrossRefGoogle Scholar
  74. 74.
    Sipido KR, Wier WG. Flux of Ca2+across the sacroplasmic reticulum of guinea pig cardiac cells during excitation contraction coupling.J Physiol1991;435:605–630PubMedGoogle Scholar
  75. 75.
    Sharma V, Tung L. Effects of uniform electric fields on intracellular calcium transients in single cardiac cells.Am J Physiol Heart Circ Physiol2002;282:H72–H79PubMedGoogle Scholar
  76. 76.
    Simpson AW. Fluorescent measurement of [Ca2+]c: basic practical considerations.Methods Mol Biol2006;312:3–36PubMedGoogle Scholar
  77. 77.
    Hadley RW, Lederer WJ. Ca2+and voltage inactivate Ca2+channels in guinea-pig ventricular myocytes through independent mechanisms.J Physiol1991;444:257–268PubMedGoogle Scholar
  78. 78.
    White E, Terrar DA. Inactivation of Ca current during the action potential in guinea-pig ventricular myocytes.Exp Physiol1992;77:153–164PubMedGoogle Scholar
  79. 79.
    Eckert R, Chad JE. Inactivation of Ca channels.Prog Biophys Mol Biol1984;44:215–267PubMedCrossRefGoogle Scholar
  80. 80.
    Grantham CJ, Cannell MB. Ca2+influx during the cardiac action potential in guinea pig ventricular myocytes.Circ Res1996;79:194–200PubMedGoogle Scholar
  81. 81.
    Langer GA, Peskoff A. Role of the diadic cleft in myocardial contractile control.Circulation1997;96:3761–3765PubMedGoogle Scholar
  82. 82.
    Mukherjee R, Spinale FG. L-type calcium channel abundance and function with cardiac hypertrophy and failure: a review.J Mol Cell Cardiol1998;30:1899–1916PubMedCrossRefGoogle Scholar
  83. 83.
    Raman V, Pollard AE, Fast VG. Shock-induced changes of Cai 2. +and Vm in myocyte cultures and computer model: dependence on the timing of shock application.Cardio-vasc Res2007;73:101–110CrossRefGoogle Scholar
  84. 84.
    Heida T. Electric field-induced effects on neuronal cell biology accompanying dielec-trophoretic trapping.Adv Anat Embryol Cell Biol2003;173:3–9Google Scholar
  85. 85.
    Lee RC, Zhang D, Hannig J. Biophysical injury mechanisms in electrical shock trauma.Annu Rev Biomed Eng2000;2:477–509PubMedCrossRefGoogle Scholar
  86. 86.
    Trollet C, Bloquel C, Scherman D, Bigey P. Electrotransfer into skeletal muscle for protein expression.Curr Gene Ther2006;6:561–578PubMedCrossRefGoogle Scholar
  87. 87.
    Goodenough DA, Goliger JA, Paul DL. Connexins, connexons, and intercellular communication.Annu Rev Biochem1996;65:475–502PubMedCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC. 2009

Authors and Affiliations

  • Vinod Sharma
    • 1
  1. 1.New Therapies and Diagnostics, Medtronic Inc.MinneapolisUSA

Personalised recommendations