What Happens During Cardiac Arrest? Understanding Cardiac Arrest Symptoms and What To Do Next
Have you ever wondered what actually happens in the body during cardiac arrest?
It’s one of those emergencies that people hear about often, yet few truly understand until they are faced with it. And when it happens, every second matters.
If you know what to look for, and more importantly, what to do, you can make the difference between life and death.
Let’s walk through what cardiac arrest is, the key cardiac arrest symptoms, and the exact steps you should take if it happens in front of you.
What Is Cardiac Arrest?
Cardiac arrest occurs when the heart suddenly stops beating effectively.
This isn’t the same as a heart attack.
A heart attack is a circulation problem caused by a blockage.
Cardiac arrest is an electrical problem. The heart’s rhythm becomes chaotic or stops altogether, which means it can no longer pump blood to the brain and vital organs.
Without immediate intervention, unconsciousness happens within seconds. Brain damage can begin in as little as four to six minutes.
That’s why understanding cardiac arrest symptoms is so important.
What Happens in the Body During Cardiac Arrest?
When cardiac arrest occurs, the heart’s electrical system malfunctions. Instead of beating in a steady, coordinated rhythm, the heart may:
- Quiver (ventricular fibrillation)
- Beat too fast (ventricular tachycardia)
- Stop completely (asystole)
Because the heart is no longer pumping blood, oxygen delivery to the brain stops, organs begin to shut down, and the person loses consciousness almost immediately.
This is why cardiac arrest is often sudden and unexpected, even in people who appeared healthy moments before.
Cardiac Arrest Symptoms: What to Watch For
Let’s be honest for a moment.
If you felt exhausted, slightly nauseous, and uncomfortable in your back… would your first thought be “heart attack”?
Probably not.
That’s exactly why signs of a heart attack in women are often overlooked.
There are three key reasons this happens:
- Symptoms overlap with everyday life. Fatigue, nausea, and discomfort are common. They don’t feel urgent.
- Lower perceived risk. Many women still underestimate their risk of heart disease.
- Internal hesitation. There’s a tendency to “wait it out” or not want to overreact.
Now flip that into a real scenario, where someone delays calling for help by 30 minutes, or an hour, or longer. It’s a missed window that really ends up mattering.
The Symptoms You Should Be Watching For
If someone suddenly collapses and isn’t breathing normally, would you recognize it as cardiac arrest?
Many people don’t because they’re often panicked or don’t understand what it is that they’re seeing.
Recognizing cardiac arrest symptoms quickly is the first and most important step.
Warning Signs That May Occur Before
In some cases, there are early warning signs minutes or even hours before:
- Chest pain or discomfort
- Shortness of breath
- Weakness or fatigue
- Dizziness or light-headedness
- Heart palpitations
These symptoms can be subtle, which is why they are often missed.
Immediate Symptoms
These happen right when cardiac arrest occurs:
- Sudden collapse
- No pulse
- No breathing or only gasping
- Loss of consciousness
If you see these signs, you are dealing with a cardiac arrest emergency.
What To Do If Someone Goes into Cardiac Arrest
If you witness cardiac arrest, follow these steps immediately.
- Call for Help
Dial emergency services right away.
If others are nearby, assign someone to call while you begin care.
- Start CPR
Begin chest compressions immediately:
- Push hard and fast in the centre of the chest
- Aim for 100 to 120 compressions per minute
- Allow full chest recoil between compressions
If you are trained, include rescue breaths. If not, hands-only CPR is still highly effective.
- Use an AED as Soon as Possible
An Automated External Defibrillator, or AED, is designed specifically for this moment.
It can:
- Analyze the heart rhythm
- Deliver a shock if needed
- Guide you with clear voice instructions
Modern AEDs are built for everyday people, not just medical professionals. They walk you through each step, removing the guesswork.
As highlighted in real emergency scenarios, AEDs are designed to restore a heart that has stopped due to an electrical issue, making them an important part of cardiac arrest response.
- Continue Until Help Arrives
Keep performing CPR and following AED prompts until emergency responders take over.
According to the Heart and Stroke Foundation, doing CPR and using a defibrillator can double a person’s chance of survival, so keep at it!
The Role of AEDs in Cardiac Arrest Survival
CPR keeps blood flowing. An AED can restart the heart.
Both are vital, but the AED is often the deciding factor in survival when the heart is in a shockable rhythm.
Automated External Defibrillators are designed for accessibility:
- Simple pad placement
- Clear, step-by-step voice coaching
- Automatic rhythm analysis
- Safe shock delivery
Some models even adjust for children or challenging environments.
If you’ve ever thought, “I wouldn’t know how to use one,” you’re not alone. But the reality is that AEDs are built to guide you in real time.
Why Training Changes Everything
Cardiac arrest survival depends almost entirely on how quickly help is provided.
According to the Red Cross, without intervention, survival decreases by about 7-10% every minute.
With fast action, survival rates can increase significantly, and brain damage can be prevented.
First aid and CPR training helps remove hesitation, and teaches you:
- How to recognize cardiac arrest symptoms quickly
- How to perform effective CPR
- How to use an AED with confidence
Most importantly, it gives you the ability to step in when it matters most.
This is exactly why ongoing education and preparation are so important in building safer workplaces and communities.
Prevention and Preparedness Go Hand in Hand
You can’t predict cardiac arrest, but you can absolutely prepare for it.
Here’s what preparedness looks like:
- Having an AED accessible
- Ensuring staff or family members are trained
- Creating an emergency response plan
- Practicing drills so the response becomes automatic
Organizations across Canada are taking a more proactive approach to cardiac emergencies, focusing on readiness rather than reaction.
Be Ready When It Matters Most
At First Edition, the goal is simple. Make sure you’re never caught unprepared.
With over 20 years of experience in first aid training and AED distribution across Canada, we help individuals, families, and workplaces build confidence in emergency situations.
Whether you are looking to get certified in CPR and first aid or equip your workplace with an AED, taking action today means being ready tomorrow.
Explore our products or training services today!
