The risk of sudden cardiac arrest (SCA) increases with age. The risk also is higher if you have underlying heart disease. Men are two to three times more likely to have SCA than women.
SCA rarely occurs in children unless they have inherited problems that make them likely to have SCA. Only a very small number of children have SCA each year.
The major risk factor for SCA is coronary heart disease (CHD). Most people who have SCA have some degree of CHD. However, these people may not know that they have CHD until SCA occurs.
Their CHD is "silent"—that is, it has no signs or symptoms. Because of this, doctors and nurses have not detected it. Many SCAs happen in people who have silent CHD and no known heart disease prior to SCA.
Many people who have SCA also have silent, or undiagnosed, heart attacks before SCA happens. These people have no clear signs of heart attack, and they don't even realize that they've had one. The chances of having SCA are higher during the first 6 months after a heart attack.
For more information about CHD risk factors, go to the Health Topics Coronary Heart Disease Risk Factors article.
Other risk factors for SCA include:
The NHLBI updates Health Topics articles on a biennial cycle based on a thorough review of research findings and new literature. The articles also are updated as needed if important new research is published. The date on each Health Topics article reflects when the content was originally posted or last revised.