The heart of an individual that experiences sudden cardiac death is often in what is termed ventricular fibrillation. This simply means that the heart is not beating normally, it is just quivering in the chest. Since it is quivering, no blood is being pumped and the person does not have a heart beat, ie they are dead.

There are multiple causes, including heart attack, drug overdose, or stroke. The cause is irrelevant, the patient is dead.

The treatment of this condition is defibrillation. An electrical current is passed through the chest that stops the quivering ( fibrillation ) and starts the heart beating again.

Paramedics can apply an electrical current that is designed to start the heart beating normally. However, it can take 5 to 10 minutes for medical assistance to arrive.