Sudden cardiac death (SCD) is an unexpected death due to heart problems, which occurs within one hour from the start of any cardiac-related symptoms. SCD is sometimes called cardiac arrest.
When the heart suddenly stops beating effectively and breathing ceases, a person is said to have experienced sudden cardiac death.
SCD is not the same as actual death. In actual death, the brain also dies. The important difference is that sudden cardiac death is potentially reversible. If it is reversed quickly enough, the brain will not die.
Sudden cardiac death is also not the same as a heart attack. A heart attack (myocardial infarction) is the result of a blockage in an artery which feeds the heart, so the heart becomes starved for oxygen. The part that has been starved is damaged beyond repair, but the heart can still beat effectively.
Causes and symptoms
Sudden cardiac death is usually caused by ventricular fibrillation (the lower chamber of the heart quivers instead of pumping in an organized rhythm). Ventricular fibrillation almost never returns to normal by itself, so the condition requires immediate intervention. Ventricular tachycardia can also lead to sudden cardiac death. The risk for SCD is higher for anyone with heart disease.
When the heart stops beating effectively and the brain is being deprived of oxygenated blood, a medical emergency exists.
Diagnosis of sudden cardiac death is made when there is a sudden loss of consciousness, breathing stops, and there is no effective heart beat.
Dorothy Elinor Stonely, The Gale Group Inc., Gale, Detroit,