CPR (cardiopulmonary resuscitation) is a first aid procedure performed on cardiac arrest victims to restore their normal heartbeat. Cardiac arrest occurs when the heart electrical functions are interrupted. It could result in abnormal heart rhythms such as ventricular fibrillation or ventricular tachycardia. Cardiac arrest could also result from slow heart rhythms also bradycardia. Ventricular fibrillation- is the most severe of all, instead of contracting to pump blood, the ventricles quiver or fibrillate. This condition is critical and requires emergency attention(CPR and AED). Ventricular tachycardia- is a condition whereby the heartbeat is too fast with over 100 beats per minute, and this condition starts with the lower heart chambers.Bradycardia- happens when the heart’s rhythm is extremely slow.