Every year in Canada, over 45,000 people experience a sudden cardiac arrest outside of a hospital. Fewer than 12% survive. The single biggest factor in survival is whether a bystander starts CPR before paramedics arrive — yet studies consistently show that fear, confusion, and misinformation stop more than half of 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Many of these hesitations come from myths — ideas picked up from movies, social media, or well-meaning but outdated advice.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 the facts you need to act with confidence.

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 irreversible damage within four to six minutes. CPR extends that window dramatically — it keeps the patient alive until definitive treatment is available.

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.

Myth 3: You Will Break Ribs and Get Sued

The truth: Rib fractures can occur during CPR, especially in older adults — and that is okay. A cracked rib heals; a dead person does not. Effective chest compressions require pushing hard (at least 5 cm / 2 inches deep for adults, one-third of the chest depth for children), and this force sometimes causes rib fractures. This is a known and accepted consequence of effective CPR, not a sign that you are doing it wrong.

As for lawsuits: every Canadian province 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 provides emergency first aid is not liable for damages resulting from that assistance, as long as they were not grossly negligent. No one in Canada has ever been successfully sued for performing CPR in good faith.

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 reduces the chance of survival by 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.

Myth 6: CPR Always Works Like It Does on TV

The truth: Television shows depict CPR as successful roughly 70% of the time. In reality, the overall survival rate for out-of-hospital cardiac arrest is around 10-12% 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 double or triple. CPR does not guarantee survival, but it gives the person the best possible chance.

Myth 7: You Can Hurt Someone by Performing CPR Incorrectly

The truth: A person in cardiac arrest is clinically dead. Their heart has stopped. They are not breathing. 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.

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 alone is the bridge until paramedics can administer drugs and advanced interventions. The AED is smart — it will not allow you to shock a person who does not need it.

Myth 9: CPR Is Only for Heart Attacks

The truth: CPR is for cardiac arrest — when the heart stops beating entirely. 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.

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 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.