Cardiac Arrest is the sudden, abrupt loss of heart function. It’s also called sudden cardiac arrest or unexpected cardiac arrest. Most cardiac arrests occur when the electrical impulses in the diseased heart become rapid (ventricular tachycardia) or chaotic (ventricular fibrillation) or both. This irregular heart rhythm (arrhythmia) causes the heart to suddenly stop beating in any coordinated manner. Cardiac arrest can be reversed if it’s treated within a few minutes with cardiopulmonary resuscitation (CPR) and an electric shock (defibrillation) to the heart to restore a normal heartbeat. Sudden cardiac death (SCD) occurs within minutes after symptoms appear unless cardiac arrest is reversed. The term “massive heart attack” is often wrongly used in the media to describe sudden death from cardiac arrest. The term “heart attack” refers to death of heart muscle tissue due to the loss of blood supply, not necessarily resulting in a cardiac arrest or the death of the heart attack victim. A heart attack may cause cardiac arrest and sudden cardiac death, but the terms aren’t synonymous.