What is SCA?

Sudden cardiac arrest occurs when the heart stops beating, leading to loss of circulation and loss of consciousness, with no blood flow to the brain and other vital organs.  Without immediate life support measures, SCA results in rapid death (Sudden Cardiac Death, or SCD). 

There are multiple causes of SCA.  The result is a terminal heart rhythm called ventricular fibrillation, which is when the heart cannot pump efficiently due to chaotic electrical activity.  However, when treated rapidly with CPR and defibrillation with an automated external defibrillator (AED), normal heart rhythm can often be restored.  Cardiac arrest preparedness can save the life of someone suffering a SCA during those critical first few minutes.  Every minute counts! 

Study after study has demonstrated that the best chance of saving a life is within the first 4 minutes of a SCA.  Survival to hospital discharge for SCA in children ages 1 to 12 is 14.4%, and in children ages 13 to 18 it is 19.9%.1   Every passing minute reduces the chance of survival by 7-10%.2  Therefore, reducing time to defibrillation will improve survival by 7-10% per minute.  Early and effective CPR has been demonstrated to double or triple the chance of SCA survival.3


1 CARES 2016 data.

2 Larsen, M., Eisenberg, M., Cummins, R., & Hallstrom, A. (1993). Predicting survival from out-of-hospital cardiac arrest: A graphic model. Annals of Emergency Medicine., 22(11), 1652-1658.

3  American Heart Association (https://cpr.heart.org/AHAECC/CPRAndECC/AboutCPRFirstAid/CPRFactsAndStats/UCM_475748_CPR-Facts-and-Stats.jsp).