What is Sudden Cardiac Arrest

Sudden Cardiac Arrest is the sudden unexpected loss of heart function, breathing and consciousness. Sudden Cardiac Arrest usually results from an abnormal heart rhythm, often as a result of underlying heart conditions. Unfortunately, many people do not realize they have underlying heart conditions — until Sudden Cardiac Arrest occurs. In fact, about two-thirds of unexpected cardiac deaths occur without prior indication of heart disease.

During a sudden cardiac arrest, heart function ceases — abruptly and without warning. When this occurs, the heart is no longer able to pump blood to the rest of the body, and in some 95% of victims, death occurs.

Sudden Cardiac Arrest is not the same as a heart attack, which occurs when blood vessels in the heart get clogged, preventing blood flow to sections of heart muscle. A heart attack, however, can lead to Sudden Cardiac Arrest by triggering an abnormal heart rhythm. Sudden Cardiac Arrest may be compared to an electrical problem in the heart, in contrast to a heart attack, which is more of a plumbing problem.

One of the common types of potentially fatal abnormal heart rhythms is ventricular fibrillation, or VF.

Without immediate treatment, Sudden Cardiac Arrest is fatal. Effective treatment generally involves Cardiopulmonary Resuscitation (CPR), use of a defibrillator to shock the heart back to a normal rhythm, and advanced life support including drug therapy and, increasingly, therapeutic hypothermia. The quicker treatment is delivered and circulation is restored, the greater the chances for survival.


Sudden Cardiac Arrest Facts

  • Sudden Cardiac Arrest (SCA) is a leading cause of death in the United States.  More people die each year from Sudden Cardiac Arrest than the number who die from colorectal cancer, breast cancer, prostate cancer, auto accidents, AIDS, firearms, and house fires combined.
  • More than 325,000 people die each year as a result of SCA.  About 3,000 people die each year from fire-related deaths.  That means you are 100 times more likely to need an AED before you will ever need a fire extinguisher.
  • SCA kills almost 1,000 people per day or approximately one person every two minutes.
  • SCA kills more Americans each year than AIDS, Breast Cancer, Colon Cancer, Prostate Cancer and Motor Vehicle Accidents combined.
  • SCA occurs in the general population at a rate of at least 1 in 500.
  • SCA is a time-critical medical emergency.  Brain death begins in 4 – 6 minutes after circulation stops.
  • The survival rate from SCA declines by 7 – 10% for each minute without circulation.
  • Only an electrical impulse from an Automated External Defibrillator (AED) can restart the heart into a normal rhythm.
  • Approximately 95% of SCA victims die before they reach a hospital.
  • The timely application of an AED could save over 100,000 lives a year in this country alone.
  • The overall SCA survival rate without an AED is 5% to 7%.
  • The SCA survival rate when CPR and an an AED are used within the first 3-5 minutes is almost 75%*.
  • SCA in children most often occurs between the ages of 10 and 19. It strikes boys four times more often than girls and occurs during exercise 60% of the time.
  • AED’s are affordable, easy to use and maintain and are in many public locations.
  • Federal Law mandates AED’s in every airport and on every commercial airliner.
  • California law requires AED’s in every health club.
  • The “Good Samaritan” law in California protects AED users from liability

* San Diego Project Heartbeat—San Diego, CA.

Three Common Causes of SCA


Commotio cordis

Is an electrical disturbance cases by a blow to the chest. It occurs most often in baseball, but has been reported in other sports and situations in which there is a blow to the chest. Researchers at the U.S. Commotio Cordis Registry studied 124 cases and found the average age is 14. Only 18 victims (14%) survived; most who survived received prompt CPR and defibrillation.

Hypertrophic Cardiomyopathy (HCM)

Is a congenital heart muscle disease. The walls of the heart’s left ventrical become abnormally thickened (hypertrophy). The structural abnormality can lead to obstruction of blood flow from the heart, causing loss of consciousness and irregular heartbeat, leading to SCA. Approximately 1 in 500 young people have this condition.

Long QT Syndrome

Is an often unrecognized congenital condition that predisposes the child to an abnormality in the heart’s electrical system, which can lead to SCA. This is a genetic disease that affects 1 in 7,000 young people. Episodes are most commonly triggered by physical exertion or emotional stress.

Signs and Symptoms of SCA


Typically, Sudden Cardiac Arrest occurs without warning. Signs of Sudden Cardiac Arrest include:
  • Sudden collapse
  • Loss of consciousness
  • Cessation of normal breathing
  • Loss of pulse and blood pressure.
Symptoms of a heart attack, in contrast, include:
  • Uncomfortable pressure, fullness, squeezing, or pain in the center of the chest, lasting more than a few minutes
  • Pain spreading to the shoulders, neck, or arms
  • Chest discomfort with lightheadedness, fainting, sweating, nausea, or shortness of breath
  • Atypical chest pain, stomach, or abdominal pain
  • Nausea or dizziness
  • Shortness of breath and difficulty breathing
  • Unexplained anxiety, weakness, or fatigue
  • Palpitations, cold sweat, or paleness.
Research about Sudden Cardiac Arrest
  • Each year in the U.S., over 325,000 people die of unexpected sudden cardiac death in an emergency department or before reaching a hospital. (Circulation 2001;104:2158-63)
  • The age-adjusted sudden cardiac death rate is higher among men than women. (MMWR Feb 15, 2002 51(06):123-6).
  • Blacks have the highest age-adjusted rate of sudden cardiac death, followed by whites. (MMWR Feb 15, 2002 51(06):123-6).
  • States with a high proportion of sudden cardiac deaths, in descending order, include: Wisconsin, Idaho, Utah, Colorado, Oregon, Connecticut, Rhode Island, South Dakota, Montana and Vermont. Hawaii has the lowest age-adjusted sudden cardiac death rate; Mississippi has the highest. (MMWR Feb 15, 2002 51(06):123-6).
  • About two-thirds of unexpected cardiac deaths occur without prior indication of heart disease. (J Am Coll Cardiol 2004;44:1268-3008-13)
  • About 60 percent of unexpected cardiac deaths are treated by emergency medical services (EMS). (JAMA 2002;288:3008-13)
  • EMS treats about 100,000 to 250,000 cardiac arrests in the U.S. annually. (JAMA 2002;288:3008-13; Ann Emerg Med 1999;34:517-25)
  • Of the cardiac arrests treated by EMS, 20 to 38 percent are found in ventricular fibrillation (VF) or ventricular tachycardia (VT) (21,000 to 91,000 cases), rhythms that can be treated with defibrillators. (Ann Emerg Med 1999;34:517-25)
  • Fifty-seven percent of adults in the U.S. say they have undergone training in cardiopulmonary resuscitation (CPR), most often due to work or school requirements. Most say they would be willing to use CPR to help a stranger. Most say they would be willing to use an automated external defibrillator (AED). Eleven percent say they have used CPR in an actual emergency. (Resuscitation 2000)
  • The incidence of lay responder defibrillation was 2.05 percent in 2002. (American Heart Association)
  • The average Sudden Cardiac Arrest survival rate is 6-7%. (Prehosp Emerg Care 1997; 1(1):45-57.)