Official reprint from UpToDate®
www.uptodate.com ©2016 UpToDate®

Automated external defibrillators

Thomas D Rea, MD, MPH
Mickey S Eisenberg, MD, PhD
Section Editor
Richard L Page, MD
Deputy Editor
Brian C Downey, MD, FACC


Sudden cardiac arrest (SCA) refers to the sudden cessation of cardiac activity with hemodynamic collapse and is most often due to sustained ventricular fibrillation (VF) or pulseless ventricular tachycardia (VT). SCA is a major public health challenge, accounting for approximately 5 to 15 percent of total mortality in industrialized nations [1-3]. (See "Overview of sudden cardiac arrest and sudden cardiac death".)

Survival from SCA remains poor. In most studies, fewer than 10 percent of patients in any cardiac rhythm and 20 percent of patients whose initial rhythm is VF survive the event [2-5]. These low survival rates are observed even with in-hospital arrests [6]. (See "Prognosis and outcomes following sudden cardiac arrest in adults".)

Although several interventions can improve the likelihood of VF resuscitation, the single most important is early delivery of an external electric shock to reset the cardiac rhythm and restore spontaneous circulation [7,8]. Early defibrillation is consistently associated with a greater likelihood of survival, which decreases by approximately 5 to 10 percent with each additional minute from collapse to defibrillation [7]. The benefit of early defibrillation is best illustrated by the outcomes following defibrillation at casinos; 74 percent with witnessed VF survived when a shock was delivered within three minutes from collapse [9].

This topic will review the development, use, allocation, and efficacy of automated external defibrillators (AEDs). Other aspects of electrical cardioversion and defibrillation are discussed separately, as are basic and advanced cardiovascular life support. (See "Basic principles and technique of electrical cardioversion and defibrillation" and "Cardioversion for specific arrhythmias" and "Basic life support (BLS) in adults" and "Advanced cardiac life support (ACLS) in adults" and "Supportive data for advanced cardiac life support in adults with sudden cardiac arrest".)


AED training — AEDs are designed to be straightforward to operate, and multiple studies have demonstrated that laypersons can operate them safely and effectively [10-14]. Nevertheless, they can be challenging to use, especially for the layperson [15-17].


Subscribers log in here

To continue reading this article, you must log in with your personal, hospital, or group practice subscription. For more information or to purchase a personal subscription, click below on the option that best describes you:
Literature review current through: Sep 2016. | This topic last updated: Dec 24, 2015.
The content on the UpToDate website is not intended nor recommended as a substitute for medical advice, diagnosis, or treatment. Always seek the advice of your own physician or other qualified health care professional regarding any medical questions or conditions. The use of this website is governed by the UpToDate Terms of Use ©2016 UpToDate, Inc.
  1. Zheng ZJ, Croft JB, Giles WH, Mensah GA. Sudden cardiac death in the United States, 1989 to 1998. Circulation 2001; 104:2158.
  2. Rea TD, Pearce RM, Raghunathan TE, et al. Incidence of out-of-hospital cardiac arrest. Am J Cardiol 2004; 93:1455.
  3. Rosamond W, Flegal K, Friday G, et al. Heart disease and stroke statistics--2007 update: a report from the American Heart Association Statistics Committee and Stroke Statistics Subcommittee. Circulation 2007; 115:e69.
  4. Peberdy MA, Kaye W, Ornato JP, et al. Cardiopulmonary resuscitation of adults in the hospital: a report of 14720 cardiac arrests from the National Registry of Cardiopulmonary Resuscitation. Resuscitation 2003; 58:297.
  5. Nichol G, Thomas E, Callaway CW, et al. Regional variation in out-of-hospital cardiac arrest incidence and outcome. JAMA 2008; 300:1423.
  6. Peberdy MA, Ornato JP, Larkin GL, et al. Survival from in-hospital cardiac arrest during nights and weekends. JAMA 2008; 299:785.
  7. Valenzuela TD, Roe DJ, Cretin S, et al. Estimating effectiveness of cardiac arrest interventions: a logistic regression survival model. Circulation 1997; 96:3308.
  8. Field JM, Hazinski MF, Sayre MR, et al. Part 1: executive summary: 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation 2010; 122:S640.
  9. Valenzuela TD, Roe DJ, Nichol G, et al. Outcomes of rapid defibrillation by security officers after cardiac arrest in casinos. N Engl J Med 2000; 343:1206.
  10. Ecker R, Rea TD, Meischke H, et al. Dispatcher assistance and automated external defibrillator performance among elders. Acad Emerg Med 2001; 8:968.
  11. Fromm RE Jr, Varon J. Automated external versus blind manual defibrillation by untrained lay rescuers. Resuscitation 1997; 33:219.
  12. Harve H, Jokela J, Tissari A, et al. Can untrained laypersons use a defibrillator with dispatcher assistance? Acad Emerg Med 2007; 14:624.
  13. Roppolo LP, Pepe PE, Campbell L, et al. Prospective, randomized trial of the effectiveness and retention of 30-min layperson training for cardiopulmonary resuscitation and automated external defibrillators: The American Airlines Study. Resuscitation 2007; 74:276.
  14. Powell J, Van Ottingham L, Schron E. Public defibrillation: increased survival from a structured response system. J Cardiovasc Nurs 2004; 19:384.
  15. Riegel B, Birnbaum A, Aufderheide TP, et al. Predictors of cardiopulmonary resuscitation and automated external defibrillator skill retention. Am Heart J 2005; 150:927.
  16. Meischke HW, Rea TD, Eisenberg MS, Rowe SM. Intentions to use an automated external defibrillator during a cardiac emergency among a group of seniors trained in its operation. Heart Lung 2002; 31:25.
  17. Riegel B, Nafziger SD, McBurnie MA, et al. How well are cardiopulmonary resuscitation and automated external defibrillator skills retained over time? Results from the Public Access Defibrillation (PAD) Trial. Acad Emerg Med 2006; 13:254.
  18. Lynch B, Einspruch EL, Nichol G, et al. Effectiveness of a 30-min CPR self-instruction program for lay responders: a controlled randomized study. Resuscitation 2005; 67:31.
  19. Meischke HW, Rea T, Eisenberg MS, et al. Training seniors in the operation of an automated external defibrillator: a randomized trial comparing two training methods. Ann Emerg Med 2001; 38:216.
  20. 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 professionals from the American Heart Association Task Force on Automatic External Defibrillation, Subcommittee on AED Safety and Efficacy. Circulation 1997; 95:1677.
  21. Kramer-Johansen J, Edelson DP, Abella BS, et al. Pauses in chest compression and inappropriate shocks: a comparison of manual and semi-automatic defibrillation attempts. Resuscitation 2007; 73:212.
  22. Nishiyama T, Nishiyama A, Negishi M, et al. Diagnostic Accuracy of Commercially Available Automated External Defibrillators. J Am Heart Assoc 2015; 4.
  23. Carpenter J, Rea TD, Murray JA, et al. Defibrillation waveform and post-shock rhythm in out-of-hospital ventricular fibrillation cardiac arrest. Resuscitation 2003; 59:189.
  24. van Alem AP, Sanou BT, Koster RW. Interruption of cardiopulmonary resuscitation with the use of the automated external defibrillator in out-of-hospital cardiac arrest. Ann Emerg Med 2003; 42:449.
  25. Valenzuela TD, Kern KB, Clark LL, et al. Interruptions of chest compressions during emergency medical systems resuscitation. Circulation 2005; 112:1259.
  26. Pytte M, Pedersen TE, Ottem J, et al. Comparison of hands-off time during CPR with manual and semi-automatic defibrillation in a manikin model. Resuscitation 2007; 73:131.
  27. Stults KR, Brown DD, Schug VL, Bean JA. Prehospital defibrillation performed by emergency medical technicians in rural communities. N Engl J Med 1984; 310:219.
  28. Weaver WD, Hill D, Fahrenbruch CE, et al. Use of the automatic external defibrillator in the management of out-of-hospital cardiac arrest. N Engl J Med 1988; 319:661.
  29. Sweeney TA, Runge JW, Gibbs MA, et al. EMT defibrillation does not increase survival from sudden cardiac death in a two-tiered urban-suburban EMS system. Ann Emerg Med 1998; 31:234.
  30. Kellermann AL, Hackman BB, Somes G, et al. Impact of first-responder defibrillation in an urban emergency medical services system. JAMA 1993; 270:1708.
  31. Watts DD. Defibrillation by basic emergency medical technicians: effect on survival. Ann Emerg Med 1995; 26:635.
  32. Auble TE, Menegazzi JJ, Paris PM. Effect of out-of-hospital defibrillation by basic life support providers on cardiac arrest mortality: a metaanalysis. Ann Emerg Med 1995; 25:642.
  33. Cobb LA, Fahrenbruch CE, Walsh TR, et al. Influence of cardiopulmonary resuscitation prior to defibrillation in patients with out-of-hospital ventricular fibrillation. JAMA 1999; 281:1182.
  34. Rea TD, Helbock M, Perry S, et al. Increasing use of cardiopulmonary resuscitation during out-of-hospital ventricular fibrillation arrest: survival implications of guideline changes. Circulation 2006; 114:2760.
  35. Tang W, Snyder D, Wang J, et al. One-shock versus three-shock defibrillation protocol significantly improves outcome in a porcine model of prolonged ventricular fibrillation cardiac arrest. Circulation 2006; 113:2683.
  36. Berg MD, Clark LL, Valenzuela TD, et al. Post-shock chest compression delays with automated external defibrillator use. Resuscitation 2005; 64:287.
  37. Berg RA, Hilwig RW, Kern KB, et al. Automated external defibrillation versus manual defibrillation for prolonged ventricular fibrillation: lethal delays of chest compressions before and after countershocks. Ann Emerg Med 2003; 42:458.
  38. Berg RA, Hilwig RW, Berg MD, et al. Immediate post-shock chest compressions improve outcome from prolonged ventricular fibrillation. Resuscitation 2008; 78:71.
  39. Bobrow BJ, Clark LL, Ewy GA, et al. Minimally interrupted cardiac resuscitation by emergency medical services for out-of-hospital cardiac arrest. JAMA 2008; 299:1158.
  40. Waalewijn RA, de Vos R, Koster RW. Out-of-hospital cardiac arrests in Amsterdam and its surrounding areas: results from the Amsterdam resuscitation study (ARREST) in 'Utstein' style. Resuscitation 1998; 38:157.
  41. 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; 23:1009.
  42. White RD, Bunch TJ, Hankins DG. Evolution of a community-wide early defibrillation programme experience over 13 years using police/fire personnel and paramedics as responders. Resuscitation 2005; 65:279.
  43. Mosesso VN Jr, Davis EA, Auble TE, et al. Use of automated external defibrillators by police officers for treatment of out-of-hospital cardiac arrest. Ann Emerg Med 1998; 32:200.
  44. Myerburg RJ, Fenster J, Velez M, et al. Impact of community-wide police car deployment of automated external defibrillators on survival from out-of-hospital cardiac arrest. Circulation 2002; 106:1058.
  45. Becker L, Husain S, Kudenchuk P, et al. Treatment of cardiac arrest with rapid defibrillation by police in King County, Washington. Prehosp Emerg Care 2014; 18:22.
  46. Groh WJ, Newman MM, Beal PE, et al. Limited response to cardiac arrest by police equipped with automated external defibrillators: lack of survival benefit in suburban and rural Indiana--the police as responder automated defibrillation evaluation (PARADE). Acad Emerg Med 2001; 8:324.
  47. Husain S, Eisenberg M. Police AED programs: a systematic review and meta-analysis. Resuscitation 2013; 84:1184.
  48. Becker L, Eisenberg M, Fahrenbruch C, Cobb L. Public locations of cardiac arrest. Implications for public access defibrillation. Circulation 1998; 97:2106.
  49. Frank RL, Rausch MA, Menegazzi JJ, Rickens M. The locations of nonresidential out-of-hospital cardiac arrests in the City of Pittsburgh over a three-year period: implications for automated external defibrillator placement. Prehosp Emerg Care 2001; 5:247.
  50. Reed DB, Birnbaum A, Brown LH, et al. Location of cardiac arrests in the public access defibrillation trial. Prehosp Emerg Care 2006; 10:61.
  51. Davies CS, Colquhoun M, Graham S, et al. Defibrillators in public places: the introduction of a national scheme for public access defibrillation in England. Resuscitation 2002; 52:13.
  52. Davis TR, Young BA, Eisenberg MS, et al. Outcome of cardiac arrests attended by emergency medical services staff at community outpatient dialysis centers. Kidney Int 2008; 73:933.
  53. Hansen CM, Lippert FK, Wissenberg M, et al. Temporal trends in coverage of historical cardiac arrests using a volunteer-based network of automated external defibrillators accessible to laypersons and emergency dispatch centers. Circulation 2014; 130:1859.
  54. Caffrey SL, Willoughby PJ, Pepe PE, Becker LB. Public use of automated external defibrillators. N Engl J Med 2002; 347:1242.
  55. Page RL, Joglar JA, Kowal RC, et al. Use of automated external defibrillators by a U.S. airline. N Engl J Med 2000; 343:1210.
  56. Culley LL, Rea TD, Murray JA, et al. Public access defibrillation in out-of-hospital cardiac arrest: a community-based study. Circulation 2004; 109:1859.
  57. Weisfeldt ML, Sitlani CM, Ornato JP, et al. Survival after application of automatic external defibrillators before arrival of the emergency medical system: evaluation in the resuscitation outcomes consortium population of 21 million. J Am Coll Cardiol 2010; 55:1713.
  58. Hallstrom AP, Ornato JP, Weisfeldt M, et al. Public-access defibrillation and survival after out-of-hospital cardiac arrest. N Engl J Med 2004; 351:637.
  59. Nichol G, Huszti E, Birnbaum A, et al. Cost-effectiveness of lay responder defibrillation for out-of-hospital cardiac arrest. Ann Emerg Med 2009; 54:226.
  60. Nichol G, Valenzuela T, Roe D, et al. Cost effectiveness of defibrillation by targeted responders in public settings. Circulation 2003; 108:697.
  61. Groeneveld PW, Kwong JL, Liu Y, et al. Cost-effectiveness of automated external defibrillators on airlines. JAMA 2001; 286:1482.
  62. Lee SJ, Anasetti C, Kuntz KM, et al. The costs and cost-effectiveness of unrelated donor bone marrow transplantation for chronic phase chronic myelogenous leukemia. Blood 1998; 92:4047.
  63. Hornberger J, Best J, Geppert J, McClellan M. Risks and costs of end-stage renal disease after heart transplantation. Transplantation 1998; 66:1763.
  64. Berdowski J, Blom MT, Bardai A, et al. Impact of onsite or dispatched automated external defibrillator use on survival after out-of-hospital cardiac arrest. Circulation 2011; 124:2225.
  65. Kitamura T, Iwami T, Kawamura T, et al. Nationwide public-access defibrillation in Japan. N Engl J Med 2010; 362:994.
  66. Blom MT, Beesems SG, Homma PC, et al. Improved survival after out-of-hospital cardiac arrest and use of automated external defibrillators. Circulation 2014; 130:1868.
  67. Hazinski MF, Markenson D, Neish S, et al. Response to cardiac arrest and selected life-threatening medical emergencies: the medical emergency response plan for schools: A statement for healthcare providers, policymakers, school administrators, and community leaders. Circulation 2004; 109:278.
  68. Lotfi K, White L, Rea T, et al. Cardiac arrest in schools. Circulation 2007; 116:1374.
  69. Kovach J, Berger S. Automated external defibrillators and secondary prevention of sudden cardiac death among children and adolescents. Pediatr Cardiol 2012; 33:402.
  70. Becker L, Gold LS, Eisenberg M, et al. Ventricular fibrillation in King County, Washington: a 30-year perspective. Resuscitation 2008; 79:22.
  71. Bardy GH, Lee KL, Mark DB, et al. Home use of automated external defibrillators for sudden cardiac arrest. N Engl J Med 2008; 358:1793.
  72. Chan PS, Krumholz HM, Nichol G, et al. Delayed time to defibrillation after in-hospital cardiac arrest. N Engl J Med 2008; 358:9.
  73. Friedman FD, Dowler K, Link MS. A public access defibrillation programme in non-inpatient hospital areas. Resuscitation 2006; 69:407.
  74. Gombotz H, Weh B, Mitterndorfer W, Rehak P. In-hospital cardiac resuscitation outside the ICU by nursing staff equipped with automated external defibrillators--the first 500 cases. Resuscitation 2006; 70:416.
  75. Chan PS, Krumholz HM, Spertus JA, et al. Automated external defibrillators and survival after in-hospital cardiac arrest. JAMA 2010; 304:2129.
  76. Weil MH, Fries M. In-hospital cardiac arrest. Crit Care Med 2005; 33:2825.
  77. Li Y, Bisera J, Tang W, Weil MH. Automated detection of ventricular fibrillation to guide cardiopulmonary resuscitation. Crit Pathw Cardiol 2007; 6:131.
  78. Berger RD, Palazzolo J, Halperin H. Rhythm discrimination during uninterrupted CPR using motion artifact reduction system. Resuscitation 2007; 75:145.
  79. Becker L, Eisenberg M, Fahrenbruch C, Cobb L. Cardiac arrest in medical and dental practices: implications for automated external defibrillators. Arch Intern Med 2001; 161:1509.
  80. Callaway CW, Menegazzi JJ. Waveform analysis of ventricular fibrillation to predict defibrillation. Curr Opin Crit Care 2005; 11:192.
  81. Eftestøl T, Wik L, Sunde K, Steen PA. Effects of cardiopulmonary resuscitation on predictors of ventricular fibrillation defibrillation success during out-of-hospital cardiac arrest. Circulation 2004; 110:10.
  82. Eisenberg MS. Is it time for over-the-counter defibrillators? JAMA 2000; 284:1435.
  83. Chang AM, Leung AC, Saynisch O, et al. Using a mobile app and mobile workforce to validate data about emergency public health resources. Emerg Med J 2013.