# Sudden cardiac arrest Condition · id `cardio:sudden-cardiac-arrest` · Cardiovascular Atlas · release `5dcd9b263fe17744` (public) > General information from published sources, not medical advice, and not reviewed by clinicians. Check the cited source before relying on anything here. The atlas's own text and curation may be reused under Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0, https://creativecommons.org/licenses/by-nc/4.0/): credit the atlas, and do not use it commercially. See the atlas About page. Text quoted from a source stays under that source's own terms, given as the source's reuse\_basis. The atlas's reuse terms do not cover it. The downloads list each quotation with its source in third\_party\_quotations. Also called: Cardiac arrest; SCA Browse, organ or system: Heart Browse, condition area: Acute care and long-term living ## In plain language Sudden cardiac arrest is when the heart abruptly stops pumping, so blood stops reaching the brain and other organs. It is an emergency. Without quick treatment it usually causes death within minutes. Anyone who sees a person collapse can help by calling 9-1-1, giving CPR and, if one is nearby, using an automated external defibrillator (AED). ## Technical summary NHLBI and MedlinePlus agree on the outline. Cardiac arrest is caused by a rhythm disturbance, with ventricular fibrillation named by MedlinePlus as the cause of most arrests and by NHLBI, with ventricular tachycardia, as the main cause. Coronary artery disease is a common condition underneath. MedlinePlus separates it from a heart attack, which is a blocked blood supply to the heart, and says an arrest can happen after or during recovery from a heart attack; NHLBI also says cardiac arrest accounts for about half of all deaths associated with heart attacks and strokes. NHLBI puts deaths from cardiac arrest in the United States between 300,000 and 450,000 a year and says nine in ten people who have an arrest outside hospital die, often within minutes. Neither page gives an age group. MeSH D006323 (Heart Arrest) is wider than this page and is stored as a broad match. ## Claims, with the population each applies to ## Context: People in cardiac arrest outside hospital, as described in NHLBI and MedlinePlus patient pages Recipient: Recipient not specified; Population: People who collapse and may be in cardiac arrest, and the bystanders around them. The pages are general patient information and do not give separate advice by age.; Care setting: Community and public places, then emergency services (the pages are written for bystanders).; Geography: United States (the NHLBI page cites US death figures and the 9-1-1 number).; Life stage: The pages do not state an age group.; Gestational age: Not reported; Postnatal age: Not reported; Follow-up: Not applicable (patient information pages). ### NHLBI lists the signs that a person may be in cardiac arrest: a sudden collapse with loss of consciousness, no breathing or only gasping, no response to shouting or shaking, and no pulse. MedlinePlus says the first sign is usually loss of consciousness. NHLBI says survival chances improve when first responders get there quickly, which is why it stresses phoning 9-1-1 before anything else. - Category: Description - Evidence stage: Evidence stage unknown - Certainty: Certainty not assessed - Applies to: Recipient: Recipient not specified; Population: People who collapse and may be in cardiac arrest, and the bystanders around them. The pages are general patient information and do not give separate advice by age.; Care setting: Community and public places, then emergency services (the pages are written for bystanders).; Geography: United States (the NHLBI page cites US death figures and the 9-1-1 number).; Life stage: The pages do not state an age group.; Gestational age: Not reported; Postnatal age: Not reported; Follow-up: Not applicable (patient information pages). - Limitations: General patient information from two government pages (NHLBI last updated 2022-05-19). NHLBI is a cite-only source, so its wording is restated and not quoted. The pages do not give an age group or a time limit for these steps. - Last checked: 2026-10-15 - Sources: 1. Supports: Cardiac Arrest: What Is Cardiac Arrest? (NHLBI) (Webpage, edition Page fetched 2026-10-15. The page says it was last updated on May 19, 2022.) Locator: Page body, list item 1. Retrieved 2026-10-15T13:53:21Z. Source state: Current. Snapshot hash: 983ed7b98dc8e782bb47746bd9a1e78f09f7a6d5be1f583b636d40b93e91748a. How it applies: Patient information page, restated in the claim. 2. Supports: Cardiac Arrest: What Is Cardiac Arrest? (NHLBI) (Webpage, edition Page fetched 2026-10-15. The page says it was last updated on May 19, 2022.) Locator: Page body, list item 2. Retrieved 2026-10-15T13:53:21Z. Source state: Current. Snapshot hash: 983ed7b98dc8e782bb47746bd9a1e78f09f7a6d5be1f583b636d40b93e91748a. How it applies: Patient information page, restated in the claim. 3. Supports: Cardiac Arrest: What Is Cardiac Arrest? (NHLBI) (Webpage, edition Page fetched 2026-10-15. The page says it was last updated on May 19, 2022.) Locator: Page body, list item 3. Retrieved 2026-10-15T13:53:21Z. Source state: Current. Snapshot hash: 983ed7b98dc8e782bb47746bd9a1e78f09f7a6d5be1f583b636d40b93e91748a. How it applies: Patient information page, restated in the claim. 4. Supports: Cardiac Arrest: What Is Cardiac Arrest? (NHLBI) (Webpage, edition Page fetched 2026-10-15. The page says it was last updated on May 19, 2022.) Locator: Page body, list item 4. Retrieved 2026-10-15T13:53:21Z. Source state: Current. Snapshot hash: 983ed7b98dc8e782bb47746bd9a1e78f09f7a6d5be1f583b636d40b93e91748a. How it applies: Patient information page, restated in the claim. 5. Supports: Cardiac Arrest: What Is Cardiac Arrest? (NHLBI) (Webpage, edition Page fetched 2026-10-15. The page says it was last updated on May 19, 2022.) Locator: Page body, AED section (quote 3). Retrieved 2026-10-15T13:53:21Z. Source state: Current. Snapshot hash: 983ed7b98dc8e782bb47746bd9a1e78f09f7a6d5be1f583b636d40b93e91748a. How it applies: Patient information page, restated in the claim. 6. Supports: Sudden Cardiac Arrest (MedlinePlus health topic) (Webpage, edition Page fetched 2026-10-15.) Locator: Summary, symptoms. Retrieved 2026-10-15T13:54:14Z. Source state: Current. Snapshot hash: 713e38eb67d03168df1bcf93f80abed751759ee7e044ac8697444ff28033a8d5. How it applies: Patient information page, restated in the claim. ## Connected pages - Rhythm conditions behind most arrests: Arrhythmia (heart rhythm problems) (`cardio:arrhythmia`) - Filed under this front: Emergency and acute care (`cardio:front-emergency-and-acute-care`) - Related to: MedlinePlus (`core:medlineplus`) - Related to: Steps after a cardiac arrest outside hospital (`cardio:pathway-out-of-hospital-cardiac-arrest`) - Related to: Cardiopulmonary resuscitation (CPR) (`cardio:cpr`) - Evaluated for this: Temperature control after cardiac arrest (`cardio:temperature-control-after-arrest`) [a claim, not a settled fact; see claim `cardio:claim-ttm2-hypothermia-vs-normothermia` and its context] - Related to: CARES cardiac arrest registry (`cardio:cares-registry`) - Investigated in: TTM2 (`cardio:ttm2`) - Evaluated for this: Automated external defibrillator (AED) (`cardio:automated-external-defibrillator`) [a claim, not a settled fact; see claim `cardio:claim-pad-lay-aed-survival` and its context] ## Provenance Content hash: 1500406c60f0b4b763777f9f9f9a47f8fb9784b160ba788f04d3e3f06c8e4d5e Last substantive edit: 2026-10-15 Evidence last checked: 2026-10-15