Every year in Canada, an estimated 60,000 people experience a cardiac arrest, most of them outside a hospital, and survival is low. The single biggest factor a bystander controls is whether CPR is started before paramedics arrive — yet fear, confusion, and misinformation stop many bystanders from acting.

Many of these hesitations come from myths — ideas picked up from movies, social media, or well-meaning but outdated advice. This article addresses the ten most common CPR myths head-on, with facts checked against current Canadian Red Cross and Heart & Stroke Foundation guidance.

Source: Heart & Stroke Foundation of Canada; Canadian Red Cross (2025).

Myth 1: CPR Restarts the Heart

The truth: CPR does not restart the heart. Its purpose is to manually pump oxygenated blood to the brain and vital organs, buying time until a defibrillator (AED) can deliver an electrical shock to restore a normal heart rhythm, or until paramedics arrive with advanced care. Without CPR, the brain begins to suffer damage within roughly four to six minutes of arrest. CPR keeps oxygenated blood moving and extends that window until definitive treatment is available.

Source: Canadian Red Cross (2025); Heart & Stroke Foundation (ILCOR 2025).

Myth 2: You Must Give Mouth-to-Mouth for CPR to Work

The truth: Hands-only CPR (continuous chest compressions without rescue breaths) is effective for adults who collapse suddenly in cardiac arrest, and it is what the Heart and Stroke Foundation of Canada recommends for untrained bystanders. When someone collapses from cardiac arrest, their blood still contains enough oxygen for several minutes — what they need most urgently is chest compressions to keep that oxygenated blood circulating. If you are trained and comfortable giving rescue breaths, the standard ratio is 30 compressions to 2 breaths. But if the choice is between hands-only CPR and doing nothing, hands-only CPR saves lives.

Source: Heart & Stroke Foundation of Canada (hands-only CPR for untrained adult bystanders); Canadian Red Cross (2025).

Source: Canadian Red Cross (2025); St. John Ambulance (two-rescuer paediatric 15:2, CSA Z1210).

Myth 3: You Will Break Ribs and Get Sued

The truth: Rib fractures can occur during CPR, especially in older adults — and that is an accepted trade-off. A cracked rib heals; a person whose heart has stopped will not survive without circulation. Effective chest compressions require pushing hard, and that force sometimes causes rib fractures. This is a known and accepted consequence of effective CPR, not a sign that you are doing it wrong.

How hard is “hard enough”? For an adult, compress the lower half of the breastbone at least 5 cm (2 inches) and no more than about 6 cm deep, at 100–120 compressions per minute, letting the chest fully recoil each time. For children and infants, depth is judged as a fraction — at least one-third of the chest’s depth — rather than a fixed number, because children range from newborn to nearly adult-sized.

Source: Canadian Red Cross (2025) and ERC/ILCOR 2025 — adult depth ≥5 cm and ≤6 cm; paediatric depth ≥⅓ of chest depth.

As for lawsuits: every Canadian province and territory has Good Samaritan legislation that protects people who provide emergency assistance in good faith. In Ontario, the Good Samaritan Act specifically states that a person who voluntarily provides emergency first aid is not liable for damages resulting from that assistance, as long as they were not grossly negligent.

Source: Good Samaritan Act, 2001 (Ontario); comparable Good Samaritan provisions exist in every province and territory.

Myth 4: You Need to Be Certified to Perform CPR

The truth: Anyone can perform CPR in an emergency — training or no training. A 911 dispatcher will talk you through the steps in real time. Certification teaches you the correct technique and builds confidence, which makes you more likely to act and more effective when you do. But a lack of certification should never stop you from trying. Doing something is almost always better than doing nothing when a person’s heart has stopped.

Myth 5: If Someone Is Unconscious, They Might Just Be Sleeping or Fainted — Wait and See

The truth: Waiting is the single most dangerous thing you can do. If a person is unresponsive and not breathing normally, assume cardiac arrest and begin CPR immediately. Every minute without CPR and defibrillation reduces the chance of survival by roughly 7–10%. If the person is merely unconscious and you start CPR, you have not harmed them — but if they are in cardiac arrest and you wait, the delay can be fatal.

Source: Canadian Red Cross (2025) — survival falls ~10% for each minute without CPR and defibrillation.

Myth 6: CPR Always Works Like It Does on TV

The truth: Television dramas depict CPR as successful most of the time. In reality, overall survival from out-of-hospital cardiac arrest is only in the range of about 10% in Canada. This is not a reason to avoid CPR — it is a reason to start it immediately, because every minute of delay makes survival less likely. When bystanders perform CPR before paramedics arrive, survival rates rise substantially. CPR does not guarantee survival, but it gives the person the best possible chance.

Source: Heart & Stroke Foundation of Canada; Canadian Red Cross (2025).

Myth 7: You Can Hurt Someone by Performing CPR Incorrectly

The truth: A person in cardiac arrest is clinically dead — their heart has stopped and they are not breathing normally. You cannot make their situation worse by attempting CPR, even if your technique is imperfect. Imperfect CPR is vastly better than no CPR. Push hard, push fast (100–120 compressions per minute), and let the chest fully recoil between compressions. That is the core of effective CPR, and it does not require perfect form.

Source: Canadian Red Cross (2025); Heart & Stroke Foundation (ILCOR 2025).

Myth 8: An AED Can Shock a Person Back to Life From Any Heart Rhythm

The truth: An AED analyses the heart rhythm and only delivers a shock if it detects a “shockable” rhythm — ventricular fibrillation or pulseless ventricular tachycardia. These are the rhythms most likely to respond to defibrillation. If the heart has no electrical activity at all (asystole — the “flatline” of television), an AED will not deliver a shock because it would not help. In these cases, CPR is the bridge until paramedics can administer drugs and advanced interventions. The AED is designed to be safe — it will not allow you to shock a person who does not need it, so apply it to any unresponsive person who is not breathing normally and follow its voice prompts.

Source: Heart & Stroke Foundation of Canada; Canadian Red Cross (2025). See our step-by-step AED guide.

Myth 9: CPR Is Only for Heart Attacks

The truth: CPR is for cardiac arrest — when the heart stops pumping effectively. A heart attack is a circulation problem (a blocked artery), while cardiac arrest is an electrical problem (the heart’s rhythm becomes chaotic or stops). A heart attack can lead to cardiac arrest, but they are different conditions. CPR is also critical in drowning, choking, drug overdose, severe allergic reactions, electrocution, and any situation where a person becomes unresponsive and stops breathing normally. Remember that in oxygen-driven emergencies like drowning and choking, rescue breaths are an essential part of CPR — hands-only compressions are not enough.

Source: Canadian Red Cross (2025); Heart & Stroke Foundation.

Myth 10: Once You Start CPR, You Cannot Stop Until Paramedics Arrive

The truth: You can stop CPR if you become too exhausted to continue effectively, if the scene becomes unsafe, if another trained person takes over, if paramedics arrive and take over care, or if the person starts breathing normally and responding. Ideally, have someone take over roughly every two minutes so compressions remain effective — fatigue sets in faster than most people expect. If you are alone and physically cannot continue, that is understandable. You did your best, and any CPR is better than none.

Source: Canadian Red Cross (2025); ILCOR 2025 — switch compressors about every 2 minutes to limit fatigue.

The core steps: hands-only CPR for an adult

If you strip away the myths, adult bystander CPR comes down to a handful of steps you can remember under pressure:

1. Check responsiveness and breathing. Tap the shoulders and shout. Look for normal breathing for no more than 10 seconds. Gasping is not normal breathing.
2. Call 911 and get an AED. Put 911 on speakerphone and send someone for the nearest AED.
3. Start chest compressions. Heel of one hand on the lower half of the breastbone, other hand on top, fingers interlocked. Push at least 5 cm and no more than 6 cm deep, at 100–120 per minute, with full recoil.
4. Add breaths only if trained and willing. After every 30 compressions, give 2 breaths. If untrained, keep doing continuous compressions.
5. Continue until help arrives. Stop only when the person breathes normally, an AED is ready, EMS takes over, or you are too exhausted — swapping rescuers about every 2 minutes.

Source: Canadian Red Cross (2025); Heart & Stroke Foundation (ILCOR 2025 BLS).