Automated external defibrillators: Do you need an AED?

An AED may save your life during cardiac arrest. Weigh the pros and cons to see if you should get one.

By Mayo Clinic Staff

If you've watched a TV medical drama, you've probably seen someone whose heart stops beating and then is suddenly shocked back to life by a doctor who yells "clear" before delivering a jolt of electricity to the person's chest.

This type of procedure isn't limited to the hospital. It can be done at home if you have an automated external defibrillator (AED), a lightweight, portable device available without a prescription. If you have severe heart disease, you're at risk of sudden cardiac arrest.

AEDs can resuscitate you only if you have a specific type of heart rhythm problem. Talk to your doctor about whether owning an AED could help save your life.

When is an AED needed?

AEDs are used to revive someone from sudden cardiac arrest, which usually occurs with a disruption in the heart's electrical activity that causes the heart to beat dangerously fast (ventricular tachycardia) or irregularly (ventricular fibrillation). Because of this altered heart rhythm (arrhythmia), your heart can't pump effectively.

The arrhythmia stops blood flow to your brain and other vital organs, usually resulting in death if not treated within minutes. If you survive, you can have permanent damage to your brain and other organs, so the sooner your heart's rhythm is restored the better.

If you're having ventricular fibrillation or ventricular tachycardia and an AED is nearby, a bystander in a public place or a family member at home can attach the self-sticking pads to your chest. The AED then reads your heart rhythm and sends an electrical current to your heart if an electric shock can correct the rhythm. If used within minutes, the jolt can restore your heart to a normal rhythm and possibly save your life.

Cardiopulmonary resuscitation (CPR) after cardiac arrest can keep blood flowing to your heart and brain for a time. But often only defibrillation can restore the heart's normal rhythm. Together they can improve your chances of survival.

How to use an AED

If you need to use an AED on someone, first call 911 or your local emergency services to get help on the way. Then begin CPR before you turn on the AED, and start CPR again after the shock is delivered if CPR is still needed.

The home AED comes with an instructional training video that shows how to use and maintain the device. If you buy an AED, everyone in your home should watch the video and review it periodically.

In an emergency, the automated external defibrillator will give you step-by-step voice instructions. It explains how to check for breathing and a pulse and how to position electrode pads on the person's chest.

Once the pads are in place, the AED automatically measures the person's heart rhythm and determines if a shock is needed. If it is, the machine tells the user to stand back and to push a button to deliver the shock. The AED is programmed not to deliver a shock if a shock isn't needed.

The AED will also guide users through CPR. The process can be repeated as needed until emergency crews take over.

Having an AED nearby when you need it

Police and ambulance crews carry AEDs, and they're commonly available in many public places, including malls, office buildings, sports arenas and airplanes. However, many cardiac arrests occur at home, so having a home AED can save precious minutes in reviving a person with ventricular fibrillation.

Proponents of home AEDs say putting them where they're needed most will save thousands of lives each year. But critics argue there's no reliable evidence that home defibrillators save more lives. Critics also fear that people won't call for emergency medical services at all or quickly enough, that they won't maintain their AED properly, or that they'll forget where it is.

Deciding if an AED is right for your home

For some people who have a high risk of cardiac arrest, having an AED can provide peace of mind and might help save their lives. Here are some things to keep in mind as you consider whether to buy an automated external defibrillator:

  • Your risk of sudden cardiac death. If you're at high risk of sudden cardiac death due to a specific heart rhythm problem, your doctor will likely recommend an implantable cardioverter-defibrillator (ICD) rather than an AED.
  • Your living arrangements. You need someone with you to use the AED if you have cardiac arrest. And the person needs to be agile enough to get on the floor to use the device and get back up. If you live alone or if the person you live with can't get up and down, a home AED might not make sense.
  • Your costs. Home AEDs can be expensive and aren't usually covered by insurance.
  • Your overall health and philosophy. If you have numerous medical problems, a terminal illness or a very weak heart that hasn't responded to treatment, you might choose not to be resuscitated from sudden cardiac death.

Tips for proper use and maintenance of AEDs

If you get an AED for your home, make sure that family, friends and visitors know where it is and how to use it. And you need to maintain it properly. Here are some tips for maintaining your home AED:

  • Register your AED with the manufacturer. That way you'll receive safety alerts and recall notices. Also, check the manufacturer's website periodically to keep current on information about your device.
  • Learn what you need to know. Consider enrolling yourself and whoever might need to use your home AED in a community education class, such as classes offered by the American Red Cross, to learn how to use your automated external defibrillator properly and to perform CPR.

    This will also enable you to come to the rescue if someone has cardiac arrest in a public place and there's an AED nearby.

  • Have a practice run using the AED as you would in an actual emergency. Because the AED works only on certain types of cardiac arrest, the people who might need to use the device should know what steps to take if the AED indicates a shock isn't needed, but the person remains unresponsive.
  • Store your AED in an easily accessible place. Make sure family, friends and visitors know where it is.
  • Keep the AED maintained properly, including installation of new batteries as needed, typically every four years, and replacement of electrode pads as needed.
  • Heed alarms. Home AEDs are designed to test themselves to make sure they're working properly. Be sure you can hear the alarm. If your machine starts beeping or you see a light flashing, call the device manufacturer. Have the number handy.
  • Buy the right AED for you. Some AEDs aren't intended for home use, but rather for emergency crews or for installation in public places. Don't be lured by websites or other sellers offering AEDs not intended for home use.

AEDs offer a way to save a life. Before buying one, talk to your doctor and do research. And don't forget to learn the basics, such as CPR.

April 19, 2017 See more In-depth

See also

  1. Infographic: Ablation for Cancer Treatment
  2. Ablation therapy
  3. Amniotic fluid embolism
  4. Amyloidosis
  5. Anemia
  6. Anorexia nervosa
  7. Aortic valve regurgitation
  8. Aplastic anemia
  9. Atrioventricular canal defect
  10. Blood tests for heart disease
  11. Bradycardia
  12. Adult congenital heart disease: What patients and families should know
  13. Adult defects
  14. Ebstein Anomaly
  15. Ebstein Anomaly Part Two: Patient Frequently Asked Questions
  16. Fact or Fiction? Debunking Exercise & Nutrition Myths for Preventing Heart Disease and Risk Factors
  17. Freezing Heart Muscle
  18. Giant Cell Myocarditis
  19. Healthy Heart Numbers
  20. Heart disease in women
  21. Heart Failure
  22. Is swimming a trigger for a Long QT Syndrome episode?
  23. Jack Long — Live Long, Beat Strong to Find a Cure
  24. Video: Leaky Valve Animation
  25. Leaky Valve Cone Procedure
  26. Relationship between Long QT Syndrome and SIDS
  27. Saved from Transplant
  28. Screenings of newborns and athletes for genetic heart disease
  29. Sports Cardiology Program
  30. Supraventricular Tachycardia
  31. Treating Long QT Patients Who Have Asthma
  32. When a fainting episode might suggest a LQTS diagnosis
  33. Broken heart: Can grief damage your heart?
  34. Broken heart syndrome
  35. Brugada syndrome
  36. Can arthritis pain medications be harmful?
  37. Can vitamins help prevent a heart attack?
  38. Cardiac ablation
  39. Infographic: Cardiac Ablation
  40. Cardiac asthma: What causes it?
  41. Cardiomyopathy
  42. Kinser's story
  43. Cardioversion
  44. Chagas disease
  45. Chelation therapy for heart disease: Does it work?
  46. Cholera
  47. Churg-Strauss syndrome
  48. Infographic: Congenital Heart Disease and Lifelong Care
  49. Congenital heart disease in adults
  50. Control your portions, control your weight
  51. Coronary bypass surgery
  52. Daily aspirin therapy
  53. Diabetic coma
  54. Dizziness
  55. Dyspnea
  56. Ebstein anomaly
  57. ECG at Mayo Clinic
  58. Echocardiogram
  59. Electrocardiogram (ECG or EKG)
  60. Enlarged heart
  61. EP study
  62. External Drive: Charles' Artificial Heart
  63. Fasting diet: Can it improve my heart health?
  64. Fatigue
  65. Flu shots and heart disease
  66. Gangrene
  67. Grass-fed beef
  68. Graves' dermopathy: How is it treated?
  69. Graves' disease
  70. Healthy eating: One step at a time
  71. Healthy Heart for Life!
  72. Healthy heart for life: Avoiding heart disease
  73. Heart arrhythmias
  74. Heart disease
  75. Heart disease in women: Understand symptoms and risk factors
  76. Heart failure
  77. Heart failure and sex: Is it safe?
  78. Heart-healthy diet: 8 steps to prevent heart disease
  79. Heart rate
  80. Heat exhaustion
  81. Holiday Heart
  82. Holter monitor
  83. How opioid addiction occurs
  84. How to tell if a loved one is abusing opioids
  85. How to use opioids safely
  86. Hyperthyroidism
  87. Implantable cardioverter-defibrillators (ICDs)
  88. Implantable loop recorder
  89. Jellyfish stings
  90. Kratom for opioid withdrawal
  91. Long QT syndrome
  92. Lyme disease
  93. Mayo Clinic Minute: Will there be a Lyme disease vaccine for humans?
  94. Menus for heart-healthy eating
  95. Mitral valve prolapse
  96. Mitral valve stenosis
  97. Multiple system atrophy (MSA)
  98. Myocarditis
  99. Nonpharmacological arrhythmia therapy
  100. Nuts and your heart: Eating nuts for heart health
  101. Omega-3 in fish
  102. Omega-6 fatty acids
  103. Opioids and other drugs: What to watch for
  104. Pacemaker
  105. Pituitary tumors
  106. Polypill: Does it treat heart disease?
  107. Premature ventricular contractions (PVCs)
  108. Prescription drug abuse
  109. Progeria
  110. Protein: Heart-healthy sources
  111. Put fish on the menu
  112. Red wine, antioxidants and resveratrol
  113. Rett syndrome
  114. Rhabdomyolysis
  115. Robotic or minimally invasive cardiac surgery for adult-adolescent congenital heart disease
  116. Infographic: Shedding light on dangerous faints
  117. Shortness of breath
  118. Snoring
  119. Snoring solution: Sleep on your side
  120. Sodium: Smarten up
  121. Heart disease prevention
  122. Stress test
  123. Symptom Checker
  124. Tachycardia
  125. Tapering off opioids: When and how
  126. Infographic: The blueprints to your heart
  127. Thyroid nodules
  128. Tilt table test
  129. Treating pain: When is an opioid the right choice?
  130. Tricuspid atresia
  131. Tricuspid valve regurgitation
  132. Video: Heart and circulatory system
  133. What are opioids and why are they dangerous?
  134. Heart failure action plan
  135. Infographic: Women and Heart Disease
  136. Yellow fever