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