Early Out-of-Hospital Experience with an Impedance-Compensating Low-Energy Biphasic Waveform Automatic External Defibrillator

  • Roger D. White
Article

Abstract

Impedance-compensating low-energy biphasic truncated exponential(BTE) waveforms are effective in transthoracic defibrillation ofshort-duration ventricular fibrillation (VF). However, the BTE waveform hasnot been examined in out-of-hospital cardiac arrest (OHCA) with patients inprolonged VF often associated with myocardial ischemia. The objective ofthis study was to evaluate the BTE waveform automatic externaldefibrillator (AED) in the out-of-hospital setting with long-duration VF.AEDs incorporating a 150-J BTE waveform were placed in 12 police squad carsand 4 paramedic-staffed advanced life support ambulances. AEDs were appliedto arrested patients by first-arriving personnel, whether police orparamedics. Data were obtained from PC Data Cards within the AED.Defibrillation was defined as at least transient termination of VF. Tenpatients, 64 ± 14 years, were treated for VF with BTE shocks.Another 8 patients were in nonshockable rhythms and the AEDs,appropriately, did not advise a shock. Five of the 10 VF arrests werewitnessed with a 911 call-to-shock time of 6.6 ± 1.7 minutes. VFdetection and defibrillation occurred in all 10 patients. Spontaneouscirculation was restored in 3 of 5 witnessed arrest patients and 1 survivedto discharge home. Fifty-one VF episodes were converted with 62 shocks. Presenting VF amplitude and rate were 0.43 ± 0.22 (0.13-0.86) mV and232 ± 62 (122-353) beats/min, respectively, and defibrillation wasachieved with the first shock in 7 of 10 patients. Including transientconversions, defibrillation occurred in 42 of 51 VF episodes (82%)with one BTE shock. Shock impedance was 85 ± 10 (39-138) ohms.Delivered energy and peak voltage were 152 ± 2 J and 1754 ±4 V, respectively. The average number of shocks per VF episode was 1.2± 0.5 (1-3). More than one shock was needed in only 9 episodes; nonerequired >3 shocks to defibrillate. Impedance-compensating low-energyBTE waveforms terminated VF in OHCA patients with a conversion rateexceeding that of higher energy monophasic waveforms. VF was terminated inall patients, including those with high impedance.

defibrillation sudden death automatic external defibrillator biphasic waveform 

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References

  1. 1.
    Ryan TJ, Anderson JL, Antman, et al. ACC/AHA guidelines for the management of patients with acute myocardial infarction: Executive summary. Circulation 1996;94: 2341–2350.Google Scholar
  2. 2.
    Bayes de Luna A, Coumel P, Leclercq JF. Ambulatory sudden cardiac death: Mechanisms of production of fatal arrhythmia on the basis of data from 157 cases. Am Heart J 1989;117:151–159.Google Scholar
  3. 3.
    Emergency Cardiac Care Committee and Subcommittees, American Heart Association. Guidelines for cardiopulmonary resuscitation and emergency cardiac care, IX: Ensuring effectiveness of community-wide emergency cardiac care. JAMA 1992;268:2289–2295.Google Scholar
  4. 4.
    Weaver WD, Copass MK, Bufi D, et al. Improved neurologic recovery and survival after early defibrillation. Circulation 1984;69:943–948.Google Scholar
  5. 5.
    Spaite DW, Hanlon T, Criss EA, et al. Prehospital cardiac arrest: The impact of witnessed collapse and bystander CPR in a metropolitan EMS system with short response times. Ann Emerg Med 1990;19:1264–1269.Google Scholar
  6. 6.
    Larsen MP, Eisenberg MS, Cummins RO, et al. Predicting survival from out-of-hospital cardiac arrest: A graphic model. Ann Emerg Med 1993;22:652–1658.Google Scholar
  7. 7.
    Weaver WD, Cobb LA, Hallstrom AP, et al. Factors influencing survival after out-of-hospital cardiac arrest. J Am Coll Cardiol 1986;7:752–757.Google Scholar
  8. 8.
    Herlitz J, Ekstrom L, Wennerblom B, et al. Survival in patients found to have ventricular fibrillation after cardiac arrest witnessed outside hospital. Eur Heart J 1994;15: 1628–1633.Google Scholar
  9. 9.
    Weisfeldt ML, Kerber RE, McGoldrick RP, et al. American Heart Association Report on the Public Access Defibrillation Conference, December 8–10, 1994. Circulation 1995;92: 2740–2747.Google Scholar
  10. 10.
    Becker LB, Ostrander MP, Barrett J, et al. Outcome of CPR in a large metropolitan area—Where are the survivors? Ann Emerg Med 1991;20:355–361.Google Scholar
  11. 11.
    Lombardi G, Gallagher EJ, Gennis P. Outcome of out-of-hospital cardiac arrest in New York City: The Pre-Hospital Arrest Survival Evaluation (PHASE) study. JAMA 1994; 271:678–683.Google Scholar
  12. 12.
    Eisenberg MS, Horwood BT, Cummins RO, et al. Cardiac arrest and resuscitation: A tale of 20 cities. Ann Emerg Med 1990;19:170–186.Google Scholar
  13. 13.
    White RD, Vukov LF, Bugliosi TF. Early defibrillation by police: Initial experience with measurement of critical time intervals and patient outcome. Ann Emerg Med 1994; 23:1099–1013.Google Scholar
  14. 14.
    White RD, Asplin BR, Bugliosi TF, Hankins DG. High discharge survival rate after out-of-hospital ventricular fibrillation with rapid defibrillation by police and paramedics. Ann Emerg Med 1996;28:480–485.Google Scholar
  15. 15.
    Winkle RA, Mead RH, Ruder MA, et al. Improved low energy defibrillation efficacy in man with the use of a biphasic truncated exponential waveform. Am Heart J 1989;117: 122–127.Google Scholar
  16. 16.
    Bardy GH, Ivey TD, Allen MD, et al. A prospective, randomized evaluation of biphasic vs. monophasic waveform pulses on defibrillation efficacy in humans. J Am Coll Cardiol 1989;14:728–733.Google Scholar
  17. 17.
    Swartz JF, Fletcher RD, Karasik PE. Optimization of biphasic waveforms for human nonthoracotomy defibrillation. Circulation 1993;33:2646–2654.Google Scholar
  18. 18.
    Jones JL, Jones RE. Decreased defibrillator-induced dysfunction with biphasic rectangular waveforms. Am J Physiol 1984;247:H792–H796.Google Scholar
  19. 19.
    Jones JL, Jones RE, Balasky G. Improved defibrillator waveform safety factor with biphasic waveforms. Am J Physiol 1983;245:H60–H65.Google Scholar
  20. 20.
    Osswald S, Trouton TG, O’Nunain SS, et al. Relation between shock-related myocardial injury and defibrillation efficacy of monophasic and biphasic shocks in a canine model. Circulation 1994;90:2501–2509.Google Scholar
  21. 21.
    Gurvich NL, Makarychev VA. Defibrillation of the heart with biphasic electrical impulses. Kardiologiya 1967;7: 109–112.Google Scholar
  22. 22.
    Kouwenhoven WB. The development of the defibrillator. Ann Intern Med 1969;71:449–457.Google Scholar
  23. 23.
    Kerber RE, Becker LB, Bourland JD, et al. Automatic external defibrillators for public access defibrillation: Recommendations for specifying and reporting arrhythmia analysis algorithm performance, incorporating new waveforms, and enhancing safety. A statement for health care professionals from the American Heart Association Task Force on Automatic External Defibrillation, Subcommittee on AED Safety and Efficacy. Circulation 1997;95:1677–1682.Google Scholar
  24. 24.
    Bardy GH, Marchlinski FE, Sharma AD, et al. Multicenter comparison of truncated biphasic shocks and standard damped sine wave monophasic shocks for transthoracic ventricular defibrillation. Circulation 1996;94:2507–2514.Google Scholar
  25. 25.
    Bardy GH, Gliner BE, Kudenchuk PJ, et al. Truncated biphasic pulses for transthoracic defibrillation. Circulation. 1995;91:1768–1774.Google Scholar
  26. 26.
    Echt DS, Barbey JT, Black JN. Influence of ventricular fibrillation duration on defibrillation energy in dogs using bidirectional pulse discharges. PACE 1988;11:1315–1323.Google Scholar
  27. 27.
    Jones JL, Swartz JF, Jones RE, Fletcher R. Increasing fibrillation duration enhances relative asymmetrical biphasic versus monophasic defibrillator waveform efficacy. Circ Res 1990;67:376–384.Google Scholar
  28. 28.
    Walcot GP, Melnick SB, Chapman FW, et al. Comparison of monophasic and biphasic waveforms for external defibrillation in an animal model of cardiac arrest and resuscitation (abstr) J Am Coll Cardiol 1995;405–406.Google Scholar
  29. 29.
    Advanced Cardiac Life Support Textbook. American Heart Association, 1994:4–11.Google Scholar
  30. 30.
    Geddes LA, Tacker WA, McFarlane J, Bourland J. Strength-duration curves for ventricular defibrillation in dogs. Circ Res 1970;25:551–560.Google Scholar
  31. 31.
    Schuder JC, Stoeckle H, West JA, Keskar PY. Transthoracic ventricular defibrillation in the dog with truncated and untruncated exponential sitmuli. IEEE Trans Biomed Eng 1971;18:1410–415.Google Scholar
  32. 32.
    Schuder JC, Rahmoeller GA, Stoekle H. Transthoracic ventricular defibrillation with triangular and trapezoidal waveforms. Circ Res 1996;19:689–694.Google Scholar
  33. 33.
    Gliner BE, Lyster TE, Dillon SM, Bardy GH. Transthoracic defibrillation of swine with monophasic and biphasic waveforms. Circulation 1995;92:1634–1643.Google Scholar
  34. 34.
    Greene HL, DiMarco JP, Kudenchuk PJ, et al. Comparison of monophasic and biphasic defibrillating pulse waveforms for transthoracic cardioversion. Am J Cardiol 1995;75: 1135–1139.Google Scholar
  35. 35.
    Behr JC, Hartley LL, York DK, Brown DD, Kerber RE. Truncated exponential versus damped sinusoidal waveform shocks for transthoracic defibrillation. J Cardiol 1996; 78:1242–1245.Google Scholar
  36. 36.
    Weaver WD, Cobb LA, Copass MK, Hallstrom AP. Ventricular defibrillation—a comparative trial using 175-J and 320-J shocks. N Engl J Med 1982;307:1101–1106.Google Scholar
  37. 37.
    Reddy RK, Gleva MJ, Dolack GL, et al. Biphasic truncated waveform transthoracic defibrillation results in less postshock ECG ST segment changes than standard damped sine wave shocks (abstr). J Am Coll Cardiol 1995;405.Google Scholar

Copyright information

© Kluwer Academic Publishers 1997

Authors and Affiliations

  • Roger D. White
    • 1
  1. 1.Mayo Clinic and Mayo Medical School; Co-Medical Director, Mayo Clinic Gold Cross Ambulance Service, IncRochester

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