Cardiac arrest means that the heart suddenly stops beating. This is due to a problem with the heart's electrical system. When cardiac arrest occurs emergency medical care needs to be provided immediately. If it is not, the person can quickly die since blood is not being pumped throughout the body.

Cardiac arrest is not the same as a heart attack. When a person has a heart attack, the blood flow to the heart is interrupted. This may be due to problems with the coronary arteries, such as a build-up of plaque, a blood clot, or a thickening of the artery walls.

Electrical System of the Heart
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Cardiac arrest may be caused by:

  • Ventricular fibrillation —a rapid, irregular heart rhythm preventing any circulation of blood (most common cause of sudden cardiac arrest)
  • Ventricular tachycardia —a rapid but regular heart rhythm that, if sustained, may turn into ventricular fibrillation
  • Dramatic slowing of heart rate due to failure of its pacemaker or severe heart block (interference with electrical conduction)
  • Respiratory arrest
  • Choking or drowning
  • Electrocution
  • Hypothermia
  • Sudden loss of blood pressure
  • Unknown causes