Sudden Cardiac Death

Sudden cardiac death is a sudden, unexpected death caused by loss of heart function. It is the largest cause of natural death in the U.S., causing about 250,000 adult deaths each year. Sudden Cardiac Death (SCD) occurs most frequently in adults in their mid-30s to mid-40s, and affects men twice as often as it does women. SCD is rare in children, affecting only 1 or 2 for every 100,000 children each year. Is Sudden Cardiac Death a Heart Attack?

No. Sudden cardiac death is not a heart attack. Heart attacks occur when there is a problem with the "plumbing" of the heart; for example, a blockage in one or more of the arteries to the heart, preventing the heart from receiving enough blood. If the oxygen in the blood cannot reach the heart muscle, the heart becomes damaged.

In contrast, during sudden cardiac death, the electrical system to the heart suddenly becomes irregular. The ventricles may flutter or quiver (ventricular fibrillation), and blood is not delivered to the body. Of greatest concern in the first few minutes after an episode ensues is that blood flow to the brain will be reduced so drastically, a person will lose consciousness. Death follows unless emergency treatment is begun immediately. Emergency treatment includes cardiopulmonary resuscitation (CPR) and, if possible, defibrillation. CPR is a manual technique using repetitive pressing to the chest and breathing into the person's airways that keeps enough oxygen and blood flowing to the brain until the normal heart rhythm is restored with an electric shock to the chest, a procedure called defibrillation. Emergency squads use portable defibrillators and frequently there are public access defibrillators (AEDs, ambulatory external defibrillators) in public locations that are intended to be available for use by citizens who observe cardiac arrest.