What Does An AED Do To The Heart?: Know The Lifesaving Process

Paramedics provide treatment for sudden cardiac arrest via an AED

Does An AED Stop The Heart?

Automated external defibrillators (AEDs) are the next frontier in cardiac care. As more people become aware of AEDs, there has been an increase in their availability and usage. An AED is designed to monitor the heart rhythms of someone that is in cardiac arrest. It analyzes the rhythm and provides a shock to restore a normal heart rhythm if clinically appropriate. So, does an AED stop the heart with this electrical shock? 

It may sound strange, but the answer is yes and no. The electrical shock from an AED does temporarily stop the heart from beating but it only lasts a few brief moments. That's all that is needed to restore the heart to a normal rhythm, leaving more time for medical treatment to arrive, and increasing their chances of survival. 

While the AED is not intended to replace a professional medical response, it can help save lives. It's important that everyone knows cardiopulmonary resuscitation (CPR) and what to do when someone is experiencing cardiac arrest, so that we are ultimately prepared if this situation ever occurs.

Why Does An AED Stop The Heart?

An AED is a device that delivers a life-saving electric shock to the heart via the chest wall. The shock is given after an abnormal heart rhythm called ventricular fibrillation (VF), has been diagnosed. This is the most serious heart rhythm problem, which can be fatal unless treated very quickly. 

The reason an AED stops a heart involves some of the basic properties of electricity. During sudden cardiac arrest, the heart stops beating normally. At this point, the cells that make up the heart muscle have already depolarized and shut down electrical activity in their area. Without AED intervention, these cells will remain depolarized and the heart beat will not be established, which effectively halts blood flow to all organs. AEDs need to be able to depolarize the entire electrical system of the heart at once, or else an irregular rhythm may continue, depriving the victim of oxygen to the brain and causing death. 

Is An AED The Only Way To Restart The Heart?

Generally during a cardiac arrest, ventricular fibrillation is occurring in the left ventricle of the heart, although it can occur in all 4 chambers. VF produces no cardiac output and is a medical emergency. The heart must be restarted or irreversible damage to the brain will occur in a matter of minutes. The most common symptoms of cardiac arrest are as follows:

  1. Sudden collapse;

  2. Loss of consciousness;

  3. Abnormal or no breathing; and

  4. No pulse.

Cardiac function can be restored using electric shock (defibrillation). This non-invasive technique uses an electric pulse to depolarize and contract at a normal rhythm (ie: A fibrillation becomes a heartbeat). There is no known non-invasive way to restart the heart in VF. Defibrillation is the only effective treatment.

The Takeaway

So, although an AED may stop a person's heart, it is not the intention of the device. This can lead to confusion between people who haven't been trained in their use. When the question is asked, "Does an AED stop the heart?" The answer needs to be more specific: it stops a dangerously abnormal heart rhythm or arrhythmia, but does not typically run the risk of stopping a normal cardiac rhythm. This can help clear up some misconceptions about this device, and spread awareness of such medical advances. To learn more about why your home or business should have an AED device, contact AED Advantage!

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