In many cases, children who die of sudden cardiac arrest have a heart arrhythmia, which are conditions that can disrupt the normal electrical function of the heart. To help prevent these deaths, it’s important to understand the use and function of automated external defibrillators (AEDs).
What Is an AED?
AEDs are portable devices that can check a person's heart rhythm and deliver electric shock to restore a normal heartbeat. AEDs can be used in emergency situations when a person has gone into sudden cardiac arrest. These defibrillators are often available in public places, and they can be used on both children and adults.
How an AED Works with the Heart’s Electrical System
To understand how an AED works, it’s helpful to understand the heart’s electrical system. The heart has an internal electrical system that controls the rate and pace of each heartbeat.
To make a heartbeat, an electrical signal is generated by the heart's sinus node, which is a small mass of specialized tissue located in the right upper chamber of the heart. This electrical signal travels to the heart similar to the way electricity flows through power lines, from the power plant to your house. The electricity moves from the upper chamber to the lower chamber, causing the heart's chambers to contract and pump out blood. Each contraction represents one heartbeat. The closure of the heart valves after contraction produces the heart's thumping sound.
Abnormalities in the heart’s electrical system can cause a heart to beat too quickly, too slowly or irregularly. These variations in heart rhythm are called arrhythmia. People with arrhythmia can have the normal pace of their heartbeat restored through electric shock from an AED.
Steps for Using an AED
It's important to be comfortable with operating an AED because quick action is needed in emergency situations. It can take EMTs about 8-12 minutes to arrive after 911 is called, and each passing minute without defibrillation decreases a person's survival chances by about 10%. An AED is most effective if it’s used within five minutes of the person collapsing.
AEDs are usually located in places with many people, like malls, airports and schools. While there are sometimes medical personnel available to operate the AED, these defibrillators are built to be used by untrained people.
The machines are equipped with audio guides that will tell you exactly what to do and when. The AED will check the heart rate of the person it’s attached to, and it will not advise you to deliver a shock unless it’s needed.