Sudden Cardiac Arrest

What is Sudden Cardiac Arrest?

Cardiac arrest is the abrupt loss of heart function in a person who may or may not have diagnosed heart disease. The time and mode of death are unexpected. It occurs instantly or shortly after symptoms appear.

Each year, more than 420,000 emergency medical services-assessed out-of-hospital cardiac arrests occur in the United States.

Is a heart attack the same as cardiac arrest?

No. The term "heart attack" is often mistakenly used to describe cardiac arrest. While a heart attack may cause cardiac arrest and sudden death, the terms don't mean the same thing. Heart attacks are caused by a blockage that stops blood flow to the heart. A heart attack (or myocardial infarction) refers to death of heart muscle tissue due to the loss of blood supply, not necessarily resulting in the death of the heart attack victim.

Cardiac arrest is caused when the heart's electrical system malfunctions. In cardiac arrest death results when the heart suddenly stops working properly. This may be caused by abnormal, or irregular, heart rhythms (called arrhythmias).

A common arrhythmia in cardiac arrest is ventricular fibrillation. This is when the heart's lower chambers suddenly start beating chaotically and don't pump blood. Death occurs within minutes after the heart stops. Cardiac arrest may be reversed if CPR (cardiopulmonary resuscitation) is performed and a defibrillator is used to shock the heart and restore a normal heart rhythm within a few minutes.

Some factors contributing to SCA include, but are not limited to:

• Inactive lifestyle
• High blood pressure
• High cholesterol
• Diabetes
• History of heart disease
• Electrocution
• Drowning
• Choking
• Illegal drug use

The reality is that sudden cardiac arrest can strike anyone, anywhere at any time. Death from SCA is sudden and unexpected, occurring instantly or shortly after the onset of symptoms. Even a seemingly healthy person can suffer cardiac arrest without warning. According to the American Heart Association, as many as 50% of SCA victims have no prior indication of heart disease - their first symptom is cardiac arrest. For those with a known history of heart attacks, the chance of sudden cardiac death is 4-6 times greater than that of the general population. Published studies have proven that early defibrillation, within the first few minutes of SCA, can save up to 60% of victims.

Source: American Heart Association