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Are you at risk?

SCA is not a random event. Although it may occur in outwardly healthy people, most victims have heart disease or other health problems, often without being aware of it.

As many as 75 percent of people who die of SCA show signs of a previous heart attack, while eighty percent have signs of coronary artery disease.

  • Previous episode of SCA
  • Previous heart attack or heart failure (75 percent of the people who die of SCA show signs of a previous heart attack)
  • Ejection fraction (EF) or the the percentage of blood that is pumped out of a filled ventricle during each beat (ejection)
    • Typical EF ranges are:
      50-75 percent - heart’s pumping ability is NORMAL
      36-49 percent - heart’s pumping ability is BELOW NORMAL
      35 percent and below - heart’s pumping ability is LOW
  • Family history of SCA

Signs and symptoms:

A number of symptoms and signs may indicate that a person is at increased risk for SCA. These include:

  • An abnormal heart rate or rhythm (arrhythmia) of unknown cause
  • An unusually rapid heart rate (tachycardia) that comes and goes, even when the person is at rest
  • Episodes of fainting of unknown cause
  • A low ejection fraction (EF): The ejection fraction is a measurement of how much blood is pumped by the ventricles with each heart beat. A healthy heart pumps 55 percent or more of its blood with each beat. People at highest risk for SCA have ejection fractions of less than 40 percent, combined with ventricular tachycardia, an abnormally fast heart rate in the lower chambers of the heart.

SCA prevention:

Reduce the risk of a "power outage" in your heart; commit to a healthy lifestyle today.

  • If you smoke, quit
  • Eat a heart-healthy diet
  • Exercise regularly
  • Lose weight if you are overweight or obese
  • Take your medications as ordered by your doctor
  • Drink alcohol in moderation.


When someone collapses from SCA, immediate cardiopulmonary resuscitation (CPR) and use of an automated external
defibrillator (AED) are essential for any chance of recovery. The AED analyzes the heart rhythm of the victim, and if necessary, a
computerized command will instruct the user to press a button to deliver an appropriate shock to restore the normal operation of the heart. These devices are failsafe and will not cause injury to the user, nor will they deliver a shock if none is needed. Defibrillation is the only definitive treatment for SCA, and survival decreases 7-10 percent for every minute without it.


The underlying medical conditions that contribute to SCA can be controlled through medical therapy. The most common classes of these drugs include beta blockers, ACE inhibitors and statins.

PacemakerInterventional procedures – a backup system for your heart

If lifestyle changes and medical therapies do not significantly reduce your risk for SCA, interventional treatment options—including an implantable cardioverter defibrillator (ICD) or pacemakers—may be considered.

Catheter ablation

Using this technique, radiofrequency energy (heat), cryotherapy (freezing), or other energy forms are used to destroy small areas of heart muscle that give rise to the abnormal electrical signals that cause rapid or irregular heart rhythms. Catheter ablation is sometimes done in patients who have an ICD to decrease the frequency of abnormal heart rhythms, and again, to reduce how often the device fires.

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