General Sudden Cardiac Facts

• Sudden Cardiac Arrest (SCA) is a leading cause of death in the United States, claiming more than 250,000 lives each year. ¹
• SCA kills more than 650 people a day, or one person every two minutes — a numbr great than the number of deaths each year from brast cancer, lung cander, stroke or AIDS. Cardiovascular disease is the leading cause of death in the U.S. and most deaths from it are attributable to SCA, where the heart abruptly and unexpectedly ceases to beat so that no blood can be pumped to the rest of the body.
• The most common cause of SCA is a heart rhythm disorder (arrhythmia) called ventricular fibrillation (VF). VF is an "electrical problem" in the heart. Without immediate emergency help, death follows within minutes of an episode of ventricular fibrillation.
• SCA most often occurs in patients with heart disease, especially those who have congestive heart failure and have had a heart attack. ²
• It is estimated that 95 percent of victims who experience SCA die before they reach a hospital or some other source of emergency help.
• As many as 75 percent of people who die of SCA show signs of a previous heart attack. Eighty percent have signs of coronary artery disease.
• SCA is not a random event. Although it may occur in outwardly healthy people, most victims do have heart disease or other health problems, often without being aware of it.
• SCA is not a heart attack, or myocardial infarction (MI), which is when a blockage in a blood vessal interrupts the flow of oxygen-rich blood to the hear, causing the heart muscle to die. If you think of your heart as a house, SCA would be a problem with the electricity; a heart attack would be a problem with the plumbing.
• SCA accounted for 10,460 (75.4 percent) of all 13,873 cardiac disease deaths in persons aged 35 to 44 years, and the proportion of cardiac deaths that occurred out-of-hospital increased with age, from 5.8 percent in persons aged 0 to4 years to 61 percent in persons aged >85 years. ³
• SCA accounted for 63.7 percent of all cardiac deaths among Caucasians, 62.3 percent among African Americans, 59.8 percent among Native Americans/Alaskan Natives, 55.8 percent among Asians/Pacific Islanders, and 54.2 percent among Hispanics. Caucasians had the highest proportion of cardiac deaths out-of-hospital, and African Americans had the highest proportion of cardiac deaths in an emergency department or dead on arrival. ⁴
• According to the Centers for Disease Control and Prevention (CDC), deaths from SCA increased 10 percent (from 2,719 in 1989 to 3,000 in 1996) in people between the ages of 15 and 34. In young women, the death rate from SCA increased 30 percent.
• African Americans are more likely to die from SCA than Caucasians.
• Wisconsin, Idaho, and Utah have the highest percentage of cardiac deaths. ⁵

Common Risk Factors

Some common risk factors include:

• High blood pressure, diabetes, high cholesterol, being overweight, smoking, poor diet (same as heart disease factors)
• Clogged arteries (coronary artery disease) or previous heart attack An abnormal heart rate or rhythm of unknown cause
• An unusually rapid heart rate that comes and goes, even when the person is at rest
• Fainting for no known reason
• A low ejection fraction (a measure of how much blood pumps with each heartbeat)

SCA often occurs in people who appear healthy, which can make it difficult to know who is at risk. Learning the risk factors is important. Preventing the causes of SCA is the best way of preventing deaths from SCA.

If any of these symptoms occur, see your doctor to have your heart tested to find out if these symptoms mean you are at increased risk for SCA.

Those at highest risk for SCA have an ejection fraction of less than 40 percent combined with ventricular tachycardia — an abnormally fast heart rhythm in the lower chambers of the heart — or an ejection fraction of less than 30 percent, even if they have not been identified as having nonsustained ventricular tachycardia.

Treatments

People who experience SCA need treatment called defibrillation or cardioversion within minutes of an electric shock to restore the heart's normal rhythm.

The defibrillation 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, automated external defibrillators (AEDs) are now available and 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.

For certain patients who are at particularly high risk, implantable cardioverter defibrillators (ICDs) are the most successful therapy to prevent sudden cardiac arrest. ICDs are pacemaker-like devices that are implanted under the skin. ICDs continually monitor the heart, and automatically deliver an electric shock if it detects ventricular fibrillation (VF) or ventricular tachycardia (VT), a rapid heart beat in the ventricles that often leads to VF and near-certain death.

Medications called "anti-arrhythmics" can also be used to treat heart rhythm disorders in addition to catheter ablation, a technique in which radiofrequency energy is used to destroy small areas in the heart that give rise to abnormal electrical signals that may contribute to rhythm disorders.

For more information on SCA visit www.stopcardiacarrest.org, a website created by theSudden Cardiac Arrest Coalition. The Coalition is comprised of 30 organizations passionate about preventing Sudden Cardiac Arrest (SCA) deaths through legislative initiatives that lead to greater public awareness, research, and access to life-saving therapies. HRS is a founding member and co-chair, along with the Sudden Cardiac Arrest Association.

¹ MMWR Weekly February 15, 2002/51(06); 123-6: State-Specific Mortality from Sudden Cardiac Death — United States, 1999.
² AHRQ Research Activities, December 2002: Researchers examine the risk factors for sudden cardiac death and management of at-risk patients.
³ MMWR Weekly February 15, 2002/51(06); 123-6: State-Specific Mortality from Sudden Cardiac Death — United States, 1999.
⁴ Same as above.
⁵ MMWR Weekly February 15, 2002/51(06); 123-6: State-Specific Mortality from Sudden Cardiac Death — United States, 1999.