Is it possible to survive a sudden cardiac arrest?

Yes: Sudden cardiac arrest is often related to an arrhythmia and can spontaneously resolve in some cases. E.G. A person passess out and regains consciousness. However, often the events is a consequence of some more serious issues (e.G heart attack, etc) and requires immediate resuscitation efforts. Immediate CPR and cardioversion is essential. When a defibrillator is not present a precordial thump.

Bystander: CPR is your best chance for survival. It raises your chances 3 fold. Learn cpr. That way when the paramedics arrive you have a chance.