How to Use an AED: Step-by-Step Guide for Cardiac Emergencies

13 April 2026

Knowing how to use an Automated External Defibrillator (AED) can make the difference between life and death for someone experiencing cardiac arrest. The likelihood of this happening in a public setting is high. That’s why we’ve created this practical guide, with clear instructions and visual references, to help you understand what to do if you ever witness such an emergency.

This guide does not replace formal training, which we strongly recommend taking with certified professionals. Hands-on training allows you to practice in simulated scenarios, ask questions, and build real-life skills. However, if you are in the process of creating a heart-safe environment, this article will give you a clear and confident starting point. Are you ready to learn how to save a life?

Understanding Cardiac Emergencies Before Using an AED

Before learning how to use an AED, it’s important to understand the type of emergency you may be facing and how to respond effectively. Recognizing the difference between cardiac arrest and a heart attack—and knowing the critical steps that improve survival—will help you act quickly and with confidence in a real-life situation.

Cardiac Arrest vs Heart Attack: Key Differences You Need to Know

Many people assume these terms mean the same thing. While both are life-threatening, they are fundamentally different conditions. Recognizing the symptoms of each is essential to respond effectively and potentially save a life.

A cardiac arrest occurs when the heart suddenly stops pumping blood. The person may collapse, lose consciousness, stop breathing (or gasp), and have no pulse. Without blood circulation, vital organs quickly fail due to lack of oxygen. Without immediate intervention, death can occur within minutes.

A heart attack (myocardial infarction), on the other hand, occurs when a blood clot blocks blood flow in a coronary artery. This lack of oxygen damages the heart muscle. Symptoms may include chest pain, shortness of breath, nausea, and sweating. Unlike cardiac arrest, the person may remain conscious initially, although their condition can worsen over time without proper medical care.

Another important difference is how bystanders can respond. In cases of cardiac arrest, anyone—even without formal training—can take action immediately while waiting for emergency services. In contrast, a heart attack requires prompt medical treatment in a hospital.

Understanding these differences is essential—but knowing what to do in the moment is what truly saves lives.

Out-of-Hospital Cardiac Arrest Survival Chain

In real-life situations, most cardiac arrests happen outside of a medical setting, which makes an immediate and structured response even more critical. Experiencing cardiac arrest in a hospital—surrounded by healthcare professionals—is very different from experiencing it in a home, workplace, or public space.

The sequence of actions used to save a life in these situations is known as the Out-of-Hospital Chain of Survival. These steps have been scientifically validated by organizations such as the American Heart Association and are most effective when performed in the correct order.

Before explaining how to use an AED, it’s helpful to briefly review these steps.

Recognition and Emergency Services Activation

As soon as cardiac arrest is suspected, call 911 or your local emergency number immediately.

High-Quality CPR (Cardiopulmonary Resuscitation)

Begin chest compressions as soon as possible to maintain blood flow to vital organs while the AED is being retrieved.

Ideally:

One person calls emergency services
Another performs chest compressions
A third retrieves the AED and applies the pads

All actions should happen simultaneously. Asking for help early is critical.

Early Defibrillation with an AED

Use the AED as soon as it becomes available to deliver a shock if needed and restore a normal heart rhythm.

Advanced Resuscitation

Healthcare professionals take over once they arrive. It is crucial not to wait for the ambulance before assisting the victim. Immediate action significantly increases survival chances.

Among these steps, early defibrillation plays a decisive role in increasing survival rates—this is where knowing how to use an AED becomes essential.

How to Use an AED: Step-by-Step Instructions

The first step is to ensure that emergency services have been contacted. Once the AED is available, follow these steps:

Turn On and Open the AED

Open the AED device. At the same time, another person should begin uninterrupted chest compressions, ideally at the rhythm of the song “Stayin’ Alive” by the Bee Gees. Compressions should reach a depth of at least 5 cm (2 inches) for adults.

Follow the AED’s Voice and Visual Instructions

Devices such as the FRED PA-1 will automatically provide step-by-step guidance through voice prompts and visual indicators. Follow these instructions carefully.

Place the electrode pads on the victim’s bare chest as shown in the diagrams included with the pads. If there is excessive chest hair, quickly shave the areas where the pads will be placed to ensure proper contact.

Allow the AED to Analyze the Heart Rhythm

The AED will assess whether the cardiac arrest is shockable. This process takes only a few seconds.

Continue performing high-quality chest compressions unless the device instructs you not to touch the patient. The built-in metronome will help guide the correct compression rhythm.

Deliver the Shock (If Advised)

When the AED indicates that a shock is required, ensure no one is touching the patient. The device will then deliver the shock.

Resume CPR Immediately

After the shock, resume chest compressions immediately and continue without interruption until emergency responders arrive. Once on site, they will take over and continue advanced care.

Be Ready to Act: Every Second Counts in a Cardiac Emergency

Assisting someone experiencing cardiac arrest can feel overwhelming, especially without medical training. However, AEDs such as the FRED PA-1, FRED PA-1 Online and FRED easyport plus by SCHILLER are designed to guide you step by step. These devices are safe, intuitive, and reliable to use in critical moments.

Having an AED readily available in schools, workplaces, and public spaces—along with proper training—is essential to improving survival outcomes.

When cardiac arrest happens, every second counts. Don’t wait for someone else to act. Step in, use the AED, and take action immediately.

Request More Information About AED Solutions in Canada

Make your workplace or public space safer with the right AED solution. Whether you’re planning a cardioprotection program or need guidance on choosing the right device, our team is here to help.