A recent study found even light to moderate smoking (one to 12 cigarettes a day) can increase the risk in women of sudden cardiac death. SCD causes about 325,000 adult deaths in the U.S., and is responsible for half of all heart disease deaths. In this segment of Vital Signs, Dr. Amir Choudhry, a cardiologist with Texas Health Presbyterian Hospital Plano, explains sudden cardiac death.
How Is Sudden Cardiac Arrest Different from a Heart Attack?
Sudden cardiac arrest is not a heart attack (myocardial infarction) but can occur during a heart attack. Heart attacks occur when there is a blockage in one or more of the arteries to the heart, preventing the heart from receiving enough oxygen-rich blood. In contrast, sudden cardiac arrest occurs when the electrical system to the heart malfunctions and suddenly becomes very irregular. The heart beats dangerously fast. The ventricles may flutter or quiver (ventricular fibrillation), and blood is not delivered to the body. In the first few minutes, the greatest concern is that blood flow to the brain will be reduced so drastically that a person will lose consciousness. Death follows unless emergency treatment is begun immediately.
What Are the Symptoms of Sudden Cardiac Arrest?
Some people may experience symptoms of sudden cardiac arrest, such as a racing heartbeat or they may feel dizzy, alerting them that a potentially dangerous heart rhythm problem has started. In over half of the cases, however, sudden cardiac arrest occurs without prior symptoms.
What Causes Sudden Cardiac Death?
Most sudden cardiac deaths are caused by abnormal heart rhythms called arrhythmias. The most common life-threatening arrhythmia is ventricular fibrillation, which is an erratic, disorganized firing of impulses from the ventricles (the heart's lower chambers). When this occurs, the heart is unable to pump blood and death will occur within minutes, if left untreated.
What Are the Risk Factors of Sudden Cardiac Arrest?
* Previous heart attack with a large area of the heart damaged.
* Coronary artery disease (Risk factors for coronary artery disease include smoking, family history of heart disease, and high cholesterol).
* Prior episode or family history of sudden cardiac arrest.
* Recreational drug abuse
* Taking drugs that are "pro-arrhythmic" may increase the risk for life-threatening arrhythmias
Can Sudden Cardiac Death Be Prevented?
If you have any of the risk factors for sudden cardiac death, it is important that you speak with your doctor about possible steps to reduce your risk.