Cardiac arrest refers to a sudden, profound disturbance in the heart’s rhythm that causes the heart to stop beating completely or slow to the point where the life is unsustainable. Cardiac arrest is not the same as a heart attack. A heart attack, while potentially life threatening, usually offers a short period of time in which treatment can save the person’s life.

Cardiac arrest must be treated immediately to avoid sudden cardiac death (death that results from cardiac arrest). Unfortunately, most people (85 percent) who experience cardiac arrest cannot get help fast enough. Those who survive the event are said to have lived through an “aborted” sudden cardiac death.

Cardiac arrest is most often caused by ventricular fibrillation, a condition in which the heart’s lower chambers quiver rather than pump blood. Ventricular fibrillation is usually accompanied by existing heart disease, especially coronary artery disease and previous heart attack. According to the American Heart Association, 90 percent of adults who succumb to cardiac arrest have two or more narrowed coronary arteries. Moreover, heart attack survivors have up to six times the rate of sudden cardiac death compared to the general population. In some rare cases, cardiac arrest can be provoked by recreational drug use or trauma.

Although there is some confusion in terms of recoding deaths due to cardiac arrest, it is estimated that about 330,000 Americans die every year due to cardiac arrest. The overwhelming majority of these are caused by ventricular fibrillation.

Prevention of cardiac arrest and sudden cardiac death is aimed at controlling underlying heart disease. Experts generally recommend that people make lifestyle changes to prevent the conditions that could trigger cardiac arrest, including atherosclerosis, which is the leading cause of coronary artery disease. Lifestyle changes may include losing weight, reducing LDL cholesterol levels, eating a heart-healthy diet and getting adequate exercise. When warranted, experts also recommend medical treatment of any underlying conditions, which may involve taking medications and/or having surgery (e.g., placing an implantable defibrillator into the patient’s chest).