Automated External Defibrillators (AEDs)...

Music At Madison Helps Local Police Departments Fight Sudden Cardiac Arrest
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It happens quickly. Without warning. It can affect anyone - healthy adults, even teenagers. It cannot be prevented. There is no vaccine. Most do not survive.

It's called Sudden Cardiac Arrest (SCA) and there's only one way to treat it. Defibrillation.

Unfortunately, 90 - 95 percent of SCA victims die because they didn't have quick access to this easy-to-administer lifesaving treatment. By making more people aware of sudden cardiac arrest and by improving access to Automated External Defibrillators (AEDs), we can increase the survival rate for these people.

Survival rates of over 50% have been achieved where easily organized AED programs have been established. These rates are twice those reported for the most effective EMS systems, and ten times better than the national EMS system average of 5%!

Every responsible household has an easily accessible fire extinguisher. In many ways, it is appropriate to think of an AED as a medical fire extinguisher!


Sudden cardiac arrest, or SCA, is a frequently misunderstood worldwide killer. It can affect anyone, anywhere, anytime. SCA occurs more than 600 times every day in the U.S. alone, killing at least 250,000 people each year. That's more people than the entire population of cities like Derby, England or Raleigh, North Carolina. SCA kills more people than house fires, AIDS, firearms, prostate and breast cancer, and automobile accidents, combined. It is one of the leading causes of death among American adults.

Yet few people are familiar with sudden cardiac arrest.

* How many times have you seen or heard about Emergency Medical Technicians flying across the lobby of your building into a waiting elevator. Our Fort Lauderdale Fire-Rescue E.M.T.s tell us that a substantial number of calls that they respond to on the Barrier Island are for Sudden Cardiac Arrest. Unfortunately, they often arrive too late! Fire-Rescue Techs have been visiting Condos to alert our residents about the lifesaving benefits of on-site Automatic External Defibrillators. Some of us are starting to listen!


  • What is sudden cardiac arrest?

    Sudden cardiac arrest (SCA) is a condition in which the heart stops beating suddenly and unexpectedly due to a malfunction in the heart's electrical system. When this happens, the heart's lower (pumping) chambers contract in a rapid, unsynchronized way. The malfunction that causes SCA is a life-threatening abnormal rhythm, or arrhythmia. The most common arrhythmia is ventricular fibrillation (VF).

    When in VF, the heart's rhythm is so chaotic (called "fibrillating") that the heart merely quivers, and is unable to pump blood to the body and brain. Once a heart has entered VF, sudden cardiac arrest occurs.

    A victim in SCA first loses his or her pulse, then consciousness, and finally the ability to breathe. But all of this happens quickly - in a matter of seconds. Without immediate treatment from a defibrillator, 90-95 percent of SCA victims will die.

    The only effective treatment for SCA is to deliver an electrical shock using a device called a defibrillator (to de-fibrillate the heart), which stops the chaotic rhythm of a heart in VF or in ventricular tachycardia (extremely rapid heartbeat), giving it the chance to restart beating with a normal rhythm.

     Cardiopulmonary resuscitation (CPR) will not restart a heart in sudden cardiac arrest. CPR is just a temporary measure used to continue a minimal supply of oxygen to the brain and other organs. When someone is in sudden cardiac arrest, defibrillation is the only way to re-establish a regular heartbeat.


  • Who can be affected by SCA?

    Unfortunately, anyone can suffer sudden cardiac arrest. SCA is unpredictable and can happen, without warning or symptoms, to anyone, anytime, anywhere...even teenagers. Although pre-existing heart disease is a common cause of cardiac arrest, many victims have never had a heart problem. Risk does increase with age.

    Without immediate treatment, only 5-10 percent of people survive SCA. But survival rates above 50 percent have been achieved in places that have successfully implemented AED programs. Survival rates can climb even higher when the person is treated within three minutes of cardiac arrest.

    These statistics are impressive, but they're still just numbers. It's not until you save a life, or meet someone whose life has been saved by an AED, that the awesome power of an AED program becomes evident.





  • Is sudden cardiac arrest the same as a heart attack?

    Sudden cardiac arrest (SCA) is not the same thing as a heart attack (myocardial infarction), although a person suffering a heart attack has an increased risk of SCA.

    Here's how they differ:

      Heart Attack Sudden Cardiac Arrest
    Cause Caused by an occlusion (blockage) in an artery that supplies blood to the heart (coronary artery). The affected heart muscle then begins to die due to lack of oxygen. Caused by an abnormal heart rhythm, usually ventricular fibrillation.
    Warning Signs Often preceded by chest, arm, upper abdomen, or jaw pain; weakness, dizziness, nausea, vomiting and sweating are common. Rarely a warning; victim collapses suddenly and has no detectable pulse
    Victim's Response Usually remains conscious and alert Always loses consciousness; unresponsive
    Risk of Death With proper treatment, many people survive. 90 - 95% will die, unless a defibrillation shock is delivered within 10 minutes of collapse.

It's not always easy to tell if someone is suffering from SCA, but the victim will typically:


  • Be unconscious
  • Have no signs of circulation (e.g. no pulse)
  • Not be breathing

Why is it important to know the difference between SCA and a heart attack? Because the treatment for each is very different:

  • For a heart attack, medical professionals must administer medications, other life-saving procedures, and sometimes surgery, to unblock blood flow to the heart muscle. Time is important, with the best results occurring if treatment is received in the first hour of symptoms.
  • For SCA, an electrical shock from a defibrillator must be delivered, the sooner the better, otherwise the victim will likely die. Laypersons can be easily trained to use an AED, thus dramatically increasing the odds of saving someone's life.
Waiting for emergency professionals (e.g. EMS) when someone is in SCA could delay treatment and could cost the person his or her life.


How is sudden cardiac arrest treated?

The only way to effectively treat sudden cardiac arrest (SCA) is with an electrical shock delivered by a defibrillator. Voltage stored by the defibrillator pushes electrical current through the heart by means of the electrodes or paddles placed on the chest. This brief pulse of current halts the chaotic activity of the heart, giving it a chance to start beating again with a normal rhythm. Delivering a shock that returns the heart to a normal rhythm is called defibrillation.

Early defibrillation is the key to surviving SCA.

Survival rates for SCA are highest when defibrillation occurs within the first few minutes. The person has the best chance of survival if the defibrillation shock is given within the first three minutes of collapsing.

But if a defibrillator is not immediately available, the outlook is grim. For each minute defibrillation is delayed, survival rates drop by about 7-10 percent-even if CPR is started immediately.

  • The rate of survival for SCA victims averages less than two percent when defibrillation is delayed ten minutes or more.
  • The average time it takes emergency crews to arrive is between 6-12 minutes.
  • If the heart isn't restarted within the first four to six minutes after the arrest, the victim may sustain irreversible brain damage.

     For Your Information!

  • The International Guidelines 2000 from the American Heart Association reports that "extraordinary survival rates-as high as 49%-have been reported in PAD (Public Access Defibrillation) programs. These rates are twice those previously reported for the most effective EMS systems.
  • In one study, when a Las Vegas casino implemented an AED program, survival rates for VF-related SCA reached 70 percent when the SCA was witnessed and the AED was used within three minutes.

Automated External Defibrillators (AEDs)

An Overview


An AED is a small, portable device that analyzes the heart's rhythm and prompts the user to deliver a defibrillation shock if it determines one is needed. Once turned on, the AED guides the user through each step of the defibrillation process by providing voice and/or visual prompts.

AEDs are specially designed for easy use by a “first responder”, who would be the first person to typically arrive on the scene of a medical emergency. A first responder can be an emergency medical services worker, a firefighter or police officer, or it can be a layperson with minimal AED training.

Time to defibrillation, the most critical factor in sudden cardiac arrest (SCA) survival, can be reduced if an AED is “on-site” and can be brought to the victim quickly. This is one of the reasons that survival rates improve in communities with active AED programs. Remember, every minute that passes before defibrillation reduces survival rates by 7-10 percent.

The goal is to improve SCA survival rates…..on-site AEDs can make the difference.


  • How does an AED work?

    Once an AED is turned on, it provides prompts to guide the user through the process. One of the first prompts instructs the user to connect the AED to the victim via the adhesive electrodes (pads) placed on the chest.

    The AED's microprocessor then analyzes the victim's heart rhythm through the electrodes using a built-in computer program. It then determines if a shock is "needed" or "necessary." More specifically:

    • The electrodes placed on the victim's body send the heart rhythm information (ECGs) to the AED.
    • The AED "reads" short segments of the heart's rhythm. It checks characteristics such as frequency, shape, slope, amplitude and heart rate.
    • Based on these characteristics, the AED determines whether or not a shock is needed and activates the appropriate user prompts or (in fully automatic versions) administers the shock.

In the above graphic series, the particular AED requires either 2 or 3 steps to save a life. Three steps if it is the semi-automatic unit and only the first two steps if it is the fully automatic version. Once you determine the person isn't breathing or conscious, you just:


  1. Push the button to release the lid and turn on the defibrillator.
  2. Pull the handle to get the electrode pads and adhere them to the person's chest as shown.
  3. Press the flashing button if told to do so. (Not necessary in fully automatic versions!)

If a shock is needed, the AED will prompt the user to press the button that delivers the shock. It will then re-analyze the heart rhythm to determine if more shocks are needed. If the unit is fully automatic, it will automatically administer shocks as needed. If a shockable rhythm is not detected, the AED will prompt the user to check the victim for a pulse, and to perform CPR if needed.


  • How does the shock “fix” SCA?

    The delivery of an electrical shock to a heart experiencing SCA briefly stops all electrical activity in the heart. This brief "break" from the previous electrical chaos can be enough for the heart to restart beating with a normal rhythm.

    Not everyone can be saved from SCA, even with defibrillation. But early defibrillation, especially when delivered within three minutes of a person's collapse from SCA, does provide the best chance.


  • Is an AED safe to use?

    An AED is safe to use by anyone who's been trained to operate it. Studies have shown the devices to be 90% sensitive (able 90% of the time to detect a rhythm that should be defibrillated) and 99% specific (able 99% of the time to recommend not shocking when defibrillation is not indicated). This level of accuracy is greater than the accuracy of emergency professionals. Because of the wide variety of situations in which it will typically be used, the AED is designed with multiple safeguards and warnings before any energy is released. The AED is programmed to deliver a shock only when it has detected VF. However, because recognizing the signs of sudden cardiac arrest should trigger an AED intervention, the AED should always be functional and available. That's why training including safety and maintenance is important.

    The AHA (American Heart Association) recommends that persons who live or work where an AED is available for use by lay rescuers participate in an AED Course. AEDs are so user-friendly that untrained rescuers can generally succeed in attaching the pads, pressing ANALYZE (if required), and delivering shocks. However, untrained rescuers probably would not know how to respond to the victim if the AED prompts “no shock indicated.” An operator needs only to follow the illustrations on the electrode pads and the control panel and listen and follow the voice prompts (for example, “Do not touch the patient”). While the fully automated version delivers shocks as needed, the partially automated AED will deliver a shock only when a shock is advised and the operator pushes the SHOCK button. This prevents a shock from being delivered accidentally.

    An AED should not be used on a child younger than 8 years old or weighing less than about 55 pounds.