Cardiac arrest can strike without warning, stopping the heart and cutting off blood flow to the brain and other vital organs. Every second counts. Without immediate action, brain damage can begin within minutes, and death can follow quickly. The good news is that anyone—even those without medical training—can save a life with the right knowledge. This step-by-step guide will walk you through exactly what to do during a cardiac arrest emergency. Whether you're at home, in the workplace, or out in public, knowing how to respond can make all the difference. When you act fast and follow these steps, you become the most important link in the chain of survival.

1. Recognize the Signs of Cardiac Arrest

The first and most critical step is recognizing that cardiac arrest is happening. Cardiac arrest is different from a heart attack. It involves a sudden loss of heart function, which means the person will collapse without warning, become unresponsive, and stop breathing normally. They will have no pulse and show no signs of life.

Acting fast requires confidence in recognizing these signs. Waiting too long to assess the situation can waste valuable minutes. Cardiac arrest may begin with faint gasping or gurgling, which some people mistake for breathing. Don’t be fooled—if someone is unresponsive and not breathing normally, treat it as cardiac arrest.

Key signs of cardiac arrest:

• Sudden collapse without cause
• No response to touch or sound
• Irregular or absent breathing (gasping)
• No detectable pulse

2. Call Emergency Services Immediately

Once you suspect cardiac arrest, the next step is to call emergency medical services (EMS) right away. In many places, this means dialing 911 or the local emergency number. Do not assume someone else has called—make sure it happens or delegate the task clearly.

Time is critical. Every minute without defibrillation or CPR reduces survival chances by about 10%. Clearly communicate to the dispatcher that the person is unresponsive, not breathing normally, and possibly in cardiac arrest. They may guide you through the next steps until help arrives.

What to do when calling EMS:

• Call 911 or your local emergency number
• State clearly: “The person is unresponsive and not breathing normally.”
• Give the location with specific details
• Follow any instructions given by the dispatcher
• Do not hang up until told to do so

3. Start Chest Compressions Immediately

If the person is unresponsive and not breathing normally, start cardiopulmonary resuscitation (CPR) immediately. The most crucial component is chest compressions. These keep blood flowing to the brain and organs until the heart can be restarted. You do not need to be medically trained—just doing high-quality chest compressions can double or even triple the person’s chance of survival.

Push hard and fast in the center of the chest. Aim for a rate of 100 to 120 compressions per minute, and a depth of at least 2 inches. Allow the chest to fully recoil between compressions. Don’t stop until trained help arrives, the person starts breathing, or an AED becomes available.

Steps to perform chest compressions:

• Kneel beside the person
• Place the heel of one hand on the center of the chest, and the other hand on top
• Lock your elbows and use your upper body to push down hard and fast
• Keep a steady rhythm (sing “Stayin’ Alive” by the Bee Gees as a pace guide)
• Do not pause compressions unless absolutely necessary

4. Use an Automated External Defibrillator (AED) If Available

An automated external defibrillator (AED) is a life-saving device designed to deliver an electric shock to restart the heart. These devices are commonly found in airports, malls, gyms, schools, and offices. They are simple to use and come with voice prompts to guide you through the process.

If an AED is nearby, ask someone to get it while you continue CPR. Once it arrives, turn it on immediately and follow the prompts. The AED will assess the heart rhythm and advise whether a shock is needed. If so, make sure no one is touching the person before pressing the shock button.

Steps for using an AED:

• Turn on the AED and follow voice instructions
• Expose the chest and attach electrode pads as shown on the device
• Let the AED analyze the heart rhythm
• If shock is advised, ensure no one is touching the person and press the button
• Resume CPR immediately after the shock, or if no shock is advised

5. Continue CPR Until Help Arrives or the Person Recovers

If an AED is not available or no shock is advised, continue chest compressions without delay. Keep the rhythm steady and strong. If another trained person is present, take turns to avoid fatigue—switch every two minutes if possible.

Even if you’re unsure of your technique, doing something is always better than doing nothing. Stopping compressions, even briefly, decreases the chances of survival. Keep compressing the chest until:

• Emergency responders take over
• An AED becomes available
• The person begins to move, breathe, or regain consciousness

During continued CPR, remember:

• Don’t stop unless absolutely necessary
• Stay focused and consistent
• Avoid checking for signs of life too frequently—just keep going
• Encourage others nearby to help or guide you

6. Give Rescue Breaths (If Trained)

While chest compressions are the priority, trained individuals can also give rescue breaths as part of full CPR. The current guideline for trained rescuers is 30 compressions followed by 2 breaths. If you are not trained or uncomfortable giving breaths, it is perfectly acceptable to do hands-only CPR.

Rescue breaths provide oxygen to the lungs, while compressions circulate it. When done correctly, this combination increases the chances of survival, especially during longer response times.

Steps for giving rescue breaths:

• After 30 compressions, open the airway by tilting the head and lifting the chin
• Pinch the nose shut
• Take a normal breath and give a rescue breath lasting 1 second
• Watch for the chest to rise
• Repeat for a second breath, then resume compressions

7. Place the Person in Recovery Position (If They Start Breathing)

If the person begins breathing normally and regains consciousness, stop CPR and place them in the recovery position. This keeps their airway open and helps prevent choking, especially if they vomit. Monitor their breathing closely and wait for emergency responders to arrive.

Do not leave them alone. Even if they seem fine, cardiac arrest can recur. Continue talking to them and reassure them. Stay calm and explain what happened, if they’re conscious and alert.

Steps for recovery position:

• Roll the person onto their side gently
• Keep the head tilted slightly back to maintain an open airway
• Bend the top leg and arm to stabilize the position
• Monitor breathing and stay with them until help arrives

8. Assist Emergency Responders

When emergency personnel arrive, step aside but be ready to relay vital information. Let them know what happened, how long the person was unresponsive, when you started CPR, and if an AED was used. This information is crucial for effective treatment and continuity of care.

If you're in a public place, help direct the responders to the scene. Clear a path, manage the crowd if needed, and ensure a safe environment for the paramedics to work.

Key information to share with responders:

• The person’s symptoms and how they were discovered
• Time of collapse
• Time CPR was initiated
• Number of shocks delivered (if AED used)
• Any known medical history, if available

9. Support the Person’s Recovery

If the person survives, your job is not yet over. They may experience confusion, fatigue, or distress following cardiac arrest. Stay calm and supportive. Comfort them until they are in the care of professionals. If they’re transported to the hospital, you can help by gathering their personal items or contacting loved ones.

In some cases, bystanders who provide life-saving aid may be invited to debrief with EMS or receive follow-up information about the patient’s condition. It’s a powerful reminder of the impact you made.

Post-cardiac arrest support may include:

• Offering reassurance and calm conversation
• Helping gather belongings or identification
• Providing details to medical staff or family
• Looking after your own emotional well-being

10. Get Trained and Spread Awareness

The best way to prepare for a cardiac emergency is to get trained in CPR and AED use. Many local health organizations and community centers offer certified courses. Even a few hours of training can equip you with the skills needed to save a life.

Beyond personal training, encourage others to learn as well. Make sure your workplace, school, or organization has access to an AED and an emergency plan. Raise awareness about the importance of rapid action during cardiac arrest—it can make all the difference.

Ways to get prepared:

• Take a CPR/AED certification course from the Red Cross or AHA
• Download apps that guide you through emergency CPR steps
• Ensure your workplace has accessible AEDs
• Encourage friends and family to get trained
• Practice CPR techniques regularly to stay confident

Conclusion

Cardiac arrest is one of the most urgent medical emergencies, but with fast action and the right knowledge, you can help save a life. From recognizing the signs to performing CPR and using an AED, every step you take matters. Calling emergency services, delivering chest compressions, and staying calm until help arrives are powerful tools that don’t require a medical degree—just courage, confidence, and care. Knowing what to do in those first critical minutes can be the deciding factor between life and death. Equip yourself with these life-saving skills and be ready to act when it matters most