Frequently Asked Questions

Answer: When a heart attack becomes a full cardiac arrest, the heart most often goes into uncoordinated electric activity called fibrillation. The heart twitches ineffectively and cannot pump blood. The AED delivers electric current to the heart muscle, momentarily stunning the heart, stopping all activity. This gives the heart an opportunity to resume beating effectively.

Question: Will an AED always resuscitate someone in cardiac arrest?

Answer:The AED treats only a heart that is fibrillating. In non-VF cardiac arrests the heart does not respond to electric current but needs medications and breathing support instead. Also, AEDs are less successful when the victim has been in cardiac arrest for longer than a few minutes, especially if no CPR was provided.

Question: Will I get zapped if I shock a victim in the rain or near water?

Answer: It is remotely possible to get shocked or to shock bystanders if there is standing water around and under the victim. Try to move the victim to a dry area and cut off wet clothing. Also be sure that the skin has been toweled off so that the electrode pads will stick to the skin. At the moment of pressing the SHOCK button you must make sure that no one, including the AED operator. Touches any part of the victim.

Question: Can an AED make mistakes?

Answer: An AED will almost never decide to shock an adult victim when the rhythm is non-VF. AEDs "miss" fine VF about 5% of the time. The internal computer uses complex analysis algorithms to determine whether to shock. If the operator has attached the AED to an adult victim who is not breathing and pulseless (in cardiac arrest), the AED will make the correct "shock" decision more than 95 times out of 100 and a correct "no shock indicated" decision more than 98 times out of 100. This level of accuracy is greater than the accuracy of emergency professionals.

Question: In addition to using the AED, how else might a layperson help at the scene of a sudden cardiac arrest?

Answer: Lay rescuers are most often going to be asked to call 911 and get the AED. The lay rescuer could assemble the pocket face mask and begin providing mouth-to mask ventilations. Responders might provide CPR or continue defibrillation if a workplace defibrillator is being used. Support and direction to the bystanders, friends, and family are appropriate. When EMS personnel arrive, the lay rescuer can provide directions and help obtain information about the victim.

Question: What actions should a CPR responder take after he or she has used an AED on a person in cardiac arrest?

Answer: There should be some type of debriefing for the employees or lay rescuers involved. Also, Collect the voice-rhythm-shock record from the AED's event documentation system. The AHA recommends strongly that AED's used in a public access or home responder setting have both rhythm and voice event documentation. AED's can record and store (at a minimum) the following information:
•  Victim rhythm throughout the resuscitation
•  Response of the AED (shock versus no shock; shockable rhythm
versus nonshockable rhythm)
•  Event and interval timing
•  Audio recording of the voices and actions recorded at the scene of a cardiac arrest.