Sudden cardiac arrest is the abrupt loss of heart function, breathing, and consciousness. It usually results in a problem with the heart's electrical system.

No but a heart attack can lead to a sudden cardiac arrest.

Yes if it treated immediately by CPR and a defibrillator.

An AED is a computerized defibrillator that will automatically analyze the heart rhythm in people who are experiencing a sudden cardiac arrest, and when appropriate it will deliver a shock to try and restore the heart to a normal rhythm