Sudden Cardiac Death (SCD), or Cardiac Arrest, kills half of all people who die of heart disease, the Number One cause of death in the United States, accounting for more than 400,000 deaths each year. SCD is a catastrophe in which the heart abruptly and without warning ceases to function. It is particularly terrifying because it kills its victims within minutes and often occurs in outwardly healthy people who have no known heart disease.
SCD is NOT A HEART ATTACK
No statistics are available for the exact number of cardiac arrests that occur each year. It's estimated, however, that more than 95 percent of victims die before reaching the hospital.
Heart Attack, or myocardial infarction (MI), is a "plumbing problem" caused by clogged or blocked blood vessels that cut off the supply of blood to the heart.
The most common cause of SCD is a heart rhythm disorder (arrhythmia) called ventricular fibrillation (VF). VF is an "electrical problem" in the heart. Suddenly, the electrical signals that regulate the pumping action of the lower chambers of the heart (ventricles) become rapid and chaotic. The normal rhythmic contractions of the ventricles stop, and the heart can't pump blood to the rest of the body. The brain is starved of oxygen, and the individual loses consciousness in seconds.
In VF, muscle contractions in the lower chambers of the heart become chaotic, and can no longer pump blood to the body.
Without immediate emergency help, death follows within minutes of an episode of ventricular fibrillation.
How Can More Lives be Saved?
The best hope for saving the lives of people who experience sudden cardiac arrest is delivery within minutes of an electric shock to restore the heart's normal rhythm. The treatment is called defibrillation or cardioversion, and may be administered with an emergency device called an external defibrillator, which delivers a brief, high-energy shock through paddles or electrode patches applied to the patient's chest.
Portable, automatic external defibrillators (AEDs) are now available that are relatively inexpensive and easy to use. Many cities now equip their police forces with these devices, and they are increasingly available on airplanes and in public buildings.
The display on an AED gives simple instructions to rescuers - and has a built-in safeguard. The defibrillator will override attempts to deliver a shock until sensors in the machine confirm the victim is in cardiac arrest.
For certain patients who are at particularly high risk, implantable cardioverter-defibrillators (ICDs) are the most successful therapy to prevent sudden cardiac death. ICDs are pacemaker-like devices that are implanted under the skin.
An ICD is a pacemaker-like device that acts as a built-in defibrillator for people who are at very high risk of cardiac arrest.
The ICD continually monitors the heart, and automatically delivers an electric shock if it detects ventricular tachycardia (VT), a rapid heart beat in the ventricles that often leads to ventricular fibrillation and near-certain death.
Identifying Risk Factors & Predicting Who is At Risk
Even with more widespread availability of defibrillators in public places, hundreds of thousands of people will continue to die of cardiac arrest. The best way to significantly reduce deaths is to identify people who are at highest risk for cardiac arrest and take steps to prevent it.
