This is different from a heart attack, in which an obstructed artery blocks blood flow to the heart. CPR will help circulate blood and oxygen to the vital organs, but it's only a stopgap. The heart's rhythm must be restored to normal using a defibrillator. The DGS AED program is an excellent example of timely delivery of a critical intervention. The portable defibrillators have simple instructions and announce directions in a mechanical voice.
Training takes about four hours.