Low-energy defibrillation with nanosecond electric shocks.

Publisher: Oxford Journals Country of Publication: England NLM ID: 0077427 Publication Model: Print Cited Medium: Internet ISSN: 1755-3245 (Electronic) Linking ISSN: 00086363 NLM ISO Abbreviation: Cardiovasc Res Subsets: MEDLINE

Publication: 2008- : Oxford : Oxford Journals
Original Publication: London, British Medical Assn.

Electric Countershock*/methods; Action Potentials/*physiology ; Heart/*physiopathology ; Ventricular Fibrillation/*physiopathology; Animals ; Energy Metabolism/physiology ; Female ; Heart/physiology ; Male ; Rabbits ; Time Factors

Aims: Reliable defibrillation with reduced energy deposition has long been the focus of defibrillation research. We studied the efficacy of single shocks of 300 ns duration in defibrillating rabbit hearts as well as the tissue damage they may cause.
Methods and Results: New Zealand white rabbit hearts were Langendorff-perfused and two planar electrodes were placed on either side of the heart. Shocks of 300 ns duration and 0.3-3 kV amplitude were generated with a transmission line generator. Single nanosecond shocks consistently induced waves of electrical activation, with a stimulation threshold of 0.9 kV (over 3 cm) and consistent activation for shock amplitudes of 1.2 kV or higher (9/9 successful attempts). We induced fibrillation (35 episodes in 12 hearts) and found that single shock nanosecond-defibrillation could consistently be achieved, with a defibrillation threshold of 2.3-2.4 kV (over 3 cm), and consistent success at 3 kV (11/11 successful attempts). Shocks uniformly depolarized the tissue, and the threshold energy needed for nanosecond defibrillation was almost an order of magnitude lower than the energy needed for defibrillation with a monophasic 10 ms shock delivered with the same electrode configuration. For the parameters studied here, nanosecond defibrillation caused no baseline shift of the transmembrane potential (that could be indicative of electroporative damage), no changes in action potential duration, and only a brief change of diastolic interval, for one beat after the shock was delivered. Histological staining with tetrazolium chloride and propidium iodide showed that effective defibrillation was not associated with tissue death or with detectable electroporation anywhere in the heart (six hearts).
Conclusion: Nanosecond-defibrillation is a promising technology that may allow clinical defibrillation with profoundly reduced energies.
(Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions please email: [email protected].)

PLoS One. 2013 Jul 23;8(7):e70278. (PMID: 23894630)
Bioelectromagnetics. 2011 Feb;32(2):148-63. (PMID: 21225892)
Biochim Biophys Acta. 2011 Mar;1808(3):792-801. (PMID: 21182825)
Am J Physiol Heart Circ Physiol. 2000 Sep;279(3):H1055-70. (PMID: 10993768)
J Cardiovasc Electrophysiol. 2008 Oct;19(10):1080-9. (PMID: 18479336)
Am Heart J. 2004 May;147(5):e20. (PMID: 15131555)
Heart Rhythm. 2011 Jan;8(1):101-8. (PMID: 20969974)
Cardiovasc Res. 1991 Dec;25(12):979-83. (PMID: 1806236)
Biophys J. 2009 Feb 18;96(4):1640-8. (PMID: 19217879)
IEEE Rev Biomed Eng. 2014;7:115-25. (PMID: 24158521)
Nature. 2011 Jul 13;475(7355):235-9. (PMID: 21753855)
Resuscitation. 2006 Mar;68(3):329-33. (PMID: 16378672)
Circulation. 2006 Nov 7;114(19):2010-8. (PMID: 17060379)
Circ Res. 2000 Oct 27;87(9):797-804. (PMID: 11055984)
Resuscitation. 2002 Aug;54(2):183-6. (PMID: 12161298)
Europace. 2002 Jan;4(1):27-39. (PMID: 11846315)
Am J Physiol Heart Circ Physiol. 2012 Aug 15;303(4):H439-49. (PMID: 22730387)
Bioelectrochemistry. 2015 Jun;103:39-43. (PMID: 25091458)
Biochem Biophys Res Commun. 2009 Jul 24;385(2):181-6. (PMID: 19450553)
J Cardiovasc Electrophysiol. 2009 Jan;20(1):85-92. (PMID: 18775052)
Am J Physiol Heart Circ Physiol. 2009 Dec;297(6):H2054-8. (PMID: 19820193)
Biochem Biophys Res Commun. 2006 Oct 20;349(2):643-53. (PMID: 16959217)
Heart Rhythm. 2013 Aug;10(8):1209-17. (PMID: 23628521)
Europace. 2005 Sep;7 Suppl 2:146-54. (PMID: 16102512)
Biochem Biophys Res Commun. 2011 Aug 19;412(1):8-12. (PMID: 21756883)
J Am Coll Cardiol. 1999 Nov 1;34(5):1595-601. (PMID: 10551711)
Cardiovasc Res. 2006 Jan;69(1):98-106. (PMID: 16226236)
J Am Coll Cardiol. 2008 Sep 2;52(10):828-35. (PMID: 18755345)
Bioelectrochemistry. 2015 Oct;105:65-71. (PMID: 26011130)
Heart Rhythm. 2013 Jun;10(6):805-10. (PMID: 23422223)
Proc Natl Acad Sci U S A. 2003 Mar 18;100(6):3203-8. (PMID: 12626744)
Curr Opin Crit Care. 2012 Oct;18(5):432-7. (PMID: 22889870)
Circ Res. 2004 Jul 9;95(1):21-33. (PMID: 15242982)
J Membr Biol. 2010 Jul;236(1):15-26. (PMID: 20623351)

R01 HL128381 United States HL NHLBI NIH HHS

Keywords: Defibrillation; Low-energy; Millisecond shocks; Nanosecond shocks; Stimulation

Date Created: 20171011 Date Completed: 20180803 Latest Revision: 20220316

20221213

PMC5852636

10.1093/cvr/cvx172

29016714