Did you know that sudden cardiac death is the most common cause of natural death in the United States today? One person dies every minute in the U.S. of sudden cardiac death. It usually strikes without warning, resulting in loss of consciousness and cardiac arrest. Without immediate treatment, death occurs within minutes. That is why it is important to diagnose and treat individuals at risk.

Dr. Igor Singer, Executive Medical Director for Methodist Cardiovascular Services, says the good news is that effective screening can identify people at risk. For those individuals who are at risk, effective treatments are available to prevent sudden cardiac death.

Dr. Singer is a leading international figure in clinical cardiac electrophysiology (the study and treatment of electrical abnormalities in the heart.) He's also the author of five widely read textbooks on the subject. Since coming to Peoria in June 2003, Dr. Singer has launched a public awareness campaign to draw attention to the problem of sudden cardiac death, as well as the treatments available.

Isn't sudden cardiac death the same as a heart attack?
No. A heart attack is a mechanical problem with the "plumbing" of your heart. One or more of the arteries that feed the heart get blocked, cutting off blood flow to the heart muscle. Part of that muscle dies.

Sudden cardiac death is an electrical problem in the heart. An abnormal electrical signal tells the heart to beat too fast and the beat becomes irregular. Instead of pumping blood and oxygen to the brain and body, the ventricles (the lower chambers of the heart) begin to quiver like jelly. This is known as ventricular fibrillation. Ventricular fibrillation almost never returns to normal by itself, so the condition requires immediate attention.

When sudden cardiac death occurs, the first priority is restore normal cardiac rhythm by defibrillation. That must occur within 15-30 seconds, or at least less than a minute. If this is not done, then the brain circulation cannot be restored.

When the heart suddenly stops beating effectively and breathing stops, a person is said to have experienced sudden cardiac death, or SCD. 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.

Who is at risk?
You may be at increased risk if you have already had a heart attack. A heart attack damages the heart muscle, leaving it scarred and weak. The scar can affect the heart's electrical system and cause it to send the abnormal electrical signal that results in ventricular fibrillation.

Recent clinical studies have identified survivors of heart attack who are at an especially high risk - those patients with impaired pumping action of the heart, known as low ejection fraction. These individuals can easily be identified by specialized heart tests.

There are other factors that can put you at risk. If you have any of the risk factors, it's important that you talk to your doctor about sudden cardiac death. Known risk factors for sudden cardiac death are:

· Previous heart attack
· Coronary artery blockages
· Heart failure
· Family history of sudden, unexpected death at middle age or younger
· Low ejection fraction (a measure of the heart's pumping ability)
· Inherited electrical abnormalities of the heart
· Other structural abnormalities of the heart

Are there any warning signs?
Often, sudden cardiac death strikes without any warning. In other cases, there may be some warning symptoms. These symptoms can also indicate other conditions and may not necessarily be an indicator of sudden cardiac death. Only a qualified cardiologist can effectively screen and diagnose dangerous conditions and separate them from the less threatening symptoms and signs.

Possible warning symptoms include, but are not necessarily confined to, one of the following:

• Rapid heartbeat, which results in lightheadedness or loss of consciousness


• Chest pressure or pain in the arms, shoulders, neck and jaw (angina)


• Shortness of breathe with ordinary tasks or with minimal exertion


• Frequent irregular heartbeats


• Sudden, unexpected loss of consciousness or fainting spells

What can you do?
If a cardiac arrest was due to ventricular tachycardia or ventricular fibrillation, survivors are at risk for another arrest, especially if they have underlying heart disease. Sudden cardiac death is reversible in most people if treatment is begun quickly. However, of the people who are resuscitated, 40% will have another SCD within two years if they do not receive appropriate treatment for the underlying cause of the episode.

You can help prevent sudden cardiac death by seeing an electrophysiologist - a heart specialist who specializes in rhythm disturbances of the heart. An electrophysiologist is specially trained to treat rhythm abnormalities that may lead to ventricular fibrillation.

An electro physiologist can use a variety of simple, non-invasive screening tests to help determine your risk of sudden cardiac death, and diagnose the cause of cardiac abnormalities. These may include one or more of the following:

• Electrocardiogram (ECG)


• ECHO cardiography


• Holter or event monitoring


• Stress testing


• Signal-averaged ECG


• T-wave alternans


• Heart rate variability

Methodist Medical Center is the only facility in central Illinois offering the T-wave alternans diagnostic screening test for sudden cardiac death. This non-invasive test has been cleared by the Food and Drug Administration (FDA) to identify patients at risk for electrical malfunctions of the heart that lead to SCD. According to Dr. Singer, "Appropriate candidates for this test are most likely patients with certain documented heart conditions including patients who have suffered heart attacks and have impaired pumping action of the heart (low ejection fraction) and those who exhibit symptoms associated with ventricular arrhythmia such as fainting, lightheadedness or palpitations."

If the screening tests suggest you may be at risk, other, more invasive, testing may be necessary, such as cardiac catheterization and electro physiologic study. The good news is that if you are found to be at risk for sudden cardiac death, effective treatment is available. Implantable cardioverter defibrillators (ICDs) save lives and are effective in preventing sudden cardiac death. Other treatments may also be necessary, including medicines, specialized catheter ablation procedures, new pacing techniques for heart failure, and occasionally, open heart surgery.

If you have had a recent heart attack or have been diagnosed with a heart condition or medical problem that may put you at increased risk for cardiac arrest and sudden cardiac death, here are some questions that you may want to ask your doctor:

• What is the risk that I will suffer cardiac arrest?


• What tests can be performed to determine if I am at high risk?


• What can I do to reduce my risk of sudden cardiac death?


• What treatments are available to reduce my risk?


• Am I a candidate for an implantable cardioverter defibrillator (ICD)?


• Should I be evaluated by an electro physiologist (a specialist in heart rhythms)?


• What is my ejection fraction? The ejection fraction of the heart is the fraction or proportion of blood that the heart pumps (or ejects) out of the left ventricular chamber with each heartbeat. People with a normal, healthy heart typically have an ejection fraction of 55 percent or greater. A low ejection fraction is one of the key indicators used to identify people are at risk of sudden cardiac death.

Remember, knowing your risk can help prevent sudden cardiac death. If you have any of the risk factors or have warning symptoms, you can call the Methodist Arrhythmia Center at 1-800-R-U-AT-RISK (1-800-782-7475) for an appointment to find out if you are at risk.

Dr. Singer is Executive Medical Director of Cardiovascular Services at Methodist. He is also a board-certified cardiologist with Methodist Medical Group Cardiology.