Cardiac Arrest

More than 356,000 people have an out-of-hospital cardiac arrest in the United States every year,1 and about 60% to 80% of them die before reaching the hospital.2

Cardiac arrest occurs when the heart suddenly and unexpectedly stops beating. Blood stops flowing to the rest of the body. People who survive cardiac arrest can have:

  • Brain injury.
  • Injury to internal organs.
  • Psychological distress, like anxiety, post-traumatic stress disorder (PTSD), and depression.

Cardiac arrest is not the same as a heart attack (myocardial infarction), myocarditis (inflammation of the heart muscle), or pericarditis (inflammation of the outer lining of the heart).

Signs of Cardiac Arrest

A person may be in cardiac arrest if they:

  • Collapse suddenly and lose consciousness (pass out).
  • Are not breathing or are gasping for air.
  • Don’t respond to shouting or shaking.
  • Don’t have a pulse.
Construction worker performing CPR on a co-worker that had cardiac arrest.

If you believe someone is having a cardiac arrest, call 9-1-1 right away, look for an automated external defibrillator (AED), and give CPR until medical professionals arrive.

Learn more at

Causes of Cardiac Arrest

Cardiac arrest has several causes, including:

  • Cardiomyopathy, which happens when the heart muscle becomes enlarged or stiff, leading to abnormal contractions.
  • Coronary artery disease, which restricts the flow of blood to the heart.
  • Valvular heart disease.
  • An arrhythmia, which is when the heart beats too slowly, too fast, or in an irregular way.

Although rare (fewer than 30 reported cases annually), a forceful blow to the chest, as from a hard ball or steering wheel, can also cause cardiac arrest. This condition is called commotio cordis (agitation of the heart).3

Groups at Higher Risk of Cardiac Arrest

People at highest risk for cardiac arrest are older adults and men. Black or African American men and women are more likely to die from out-of-hospital cardiac arrest than White men and women.4


  1. Benjamin EJ, Virani SS, Callaway CW, Chamberlain AM, Chang AR, Cheng S, Chiuve SE, Cushman M, Delling FN, Deo R, de Ferranti SD. Heart disease and stroke statistics—2018 update: a report from the American Heart Association. Circulation. 2018 Mar 20;137(12):e67-492. Table 16-1.
  2. Tsao CW, Aday AW, Almarzooq ZI, Anderson CA, Arora P, Avery CL, Baker-Smith CM, Beaton AZ, Boehme AK, Buxton AE, Commodore-Mensah Y. Heart disease and stroke statistics—2023 update: a report from the American Heart Association. Circulation. 2023 Feb 21;147(8):e93-621. Table 19-5 and 19-6.
  3. Tainter CR, Hughes PG. Commotio Cordis. [Updated 2023 Feb 5]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from:
  4. Zhao DI, Post WS, Blasco-Colmenares E, Cheng A, Zhang Y, Deo R, Pastor-Barriuso R, Michos ED, Sotoodehnia N, Guallar E. Racial differences in sudden cardiac death: atherosclerosis risk in communities study (ARIC). Circulation. 2019 Apr 2;139(14):1688-97.