Cardiac arrest is a sudden loss of blood flow throughout the body resulting from the failure of the heart. It is a rapidly fatal medical emergency requiring immediate intervention with cardiopulmonary resuscitation (CPR) until further treatment can be provided. Cardiac arrest results in rapid loss of consciousness and breathing may be abnormal or absent. While cardiac arrest may be caused by heart attack or heart failure, these are not the same, and in 15 to 25% of cases there is a non-cardiac cause. Some individuals may experience chest pain, shortness of breath or nausea immediately before entering cardiac arrest. Additionally, an elevated heart rate and feelings of light-headedness may occur before the episode. If not intervened by CPR and defibrillation, cardiac arrest typically leads to death within minutes.