An AED will not save everyone who is experiencing sudden cardiac arrest.
Unfortunately, sometimes the damage to a patient’s heart, which caused the sudden cardiac arrest, is too extensive, and therefore, the heart cannot recover. Sometimes a patient is found too late in the cardiac arrest process to be brought back.
The longer the delay before CPR and defibrillation (shock) are administered, the less likely are their chances of survival. Ideally, CPR should begin immediately upon collapse and defibrillation should occur no more than 3-5 minutes after collapse. For every minute, which passes from patient collapse to shock, the likelihood of recovery diminishes by 10%. CPR is critical to keep blood flowing to the brain during cardiac arrest because, without it, the brain begins to die within 4-6 minutes of collapse.