How to Perform CPR

CPR — cardiopulmonary resuscitation — is an emergency procedure that manually maintains blood circulation and oxygenation when the heart has stopped beating. It is the single most important bystander skill in cardiac arrest: survival rates for out-of-hospital cardiac arrest are dramatically higher when CPR is started immediately by bystanders before EMS arrival. Every minute without CPR after cardiac arrest reduces survival by approximately 10%; immediate high-quality CPR can more than double survival rates.

Understanding Cardiac Arrest

Cardiac arrest is the sudden, unexpected loss of heart function — the heart stops pumping blood. It is not the same as a heart attack (in which blood flow to heart muscle is blocked but the heart continues beating). Cardiac arrest renders the patient unresponsive and not breathing. Without immediate CPR and defibrillation, death occurs within minutes from lack of oxygen to the brain.

The most common cause of sudden cardiac arrest in adults is ventricular fibrillation (VF) — chaotic, uncoordinated electrical activity in the heart. VF is a "shockable" rhythm — a defibrillator (AED) can convert it back to normal rhythm. But every minute without defibrillation decreases the chance of success; CPR maintains minimal blood flow to buy time until defibrillation.