{
  "release_id": "73130c34862e2d06",
  "id": "cardio:guide-heart-attack-cardiac-arrest-now",
  "owner": "cardio",
  "kind": "patient_guide",
  "slug": "heart-attack-or-cardiac-arrest-what-to-do-now",
  "name": "Heart attack or cardiac arrest: what to do now",
  "aliases": [],
  "atlases": [
    "cardio"
  ],
  "summary_plain": "Heart attack signs and cardiac arrest signs, what the sources say to do, and what CPR and an AED are. It does not replace emergency care.",
  "summary_technical": "A static guide built from two MedlinePlus health topic pages and three NHLBI pages restated in the atlas’s own words. Every sentence cites a source, and the emergency wording is quoted from MedlinePlus only.",
  "editorial_state": "draft",
  "last_substantive_edit": "2026-10-15",
  "last_evidence_check": "2026-10-15",
  "next_review_due": "2027-04-15",
  "identifiers": [],
  "navigation": {
    "cardio": {
      "condition-area": [
        "acute-care-and-long-term-living"
      ]
    }
  },
  "payload": {
    "purpose": "urgent_signs",
    "audience": "Adults, and the people with them",
    "about": [
      "cardio:heart-attack-warning-signs",
      "cardio:myocardial-infarction",
      "cardio:sudden-cardiac-arrest",
      "cardio:cpr",
      "cardio:automated-external-defibrillator"
    ],
    "reading_grade_target": 7,
    "scope_note": "Written from two MedlinePlus health topic pages and three NHLBI pages that are restated in the atlas’s own words. The sources are US government pages, and their emergency wording is US wording.",
    "warning_blocks": [
      {
        "heading": "Signs of a heart attack",
        "signs": [
          {
            "id": "ha-chest",
            "text": "Chest discomfort, often in the center or on the left side of the chest, is among the most common signs.",
            "cites": [
              {
                "snapshot_id": "cardio:medlineplus-heartattack-2026-10-14",
                "locator": "Summary, heart attack symptoms"
              }
            ]
          },
          {
            "id": "ha-feel",
            "text": "Chest discomfort can feel like pressure, squeezing, fullness or pain, or it can feel like heartburn or indigestion.",
            "cites": [
              {
                "snapshot_id": "cardio:medlineplus-heartattack-2026-10-14",
                "locator": "Summary, heart attack symptoms"
              }
            ]
          },
          {
            "id": "ha-time",
            "text": "Chest discomfort usually lasts longer than a few minutes, and it may go away and come back.",
            "cites": [
              {
                "snapshot_id": "cardio:medlineplus-heartattack-2026-10-14",
                "locator": "Summary, heart attack symptoms"
              }
            ]
          },
          {
            "id": "ha-breath",
            "text": "Shortness of breath is also one of the most common signs, and sometimes it is the only symptom.",
            "cites": [
              {
                "snapshot_id": "cardio:medlineplus-heartattack-2026-10-14",
                "locator": "Summary, heart attack symptoms"
              }
            ]
          },
          {
            "id": "ha-breath-when",
            "text": "Shortness of breath can come before or during chest discomfort, and it can happen at rest or with a little physical activity.",
            "cites": [
              {
                "snapshot_id": "cardio:medlineplus-heartattack-2026-10-14",
                "locator": "Summary, heart attack symptoms"
              },
              {
                "snapshot_id": "cardio:medlineplus-heartattack-2026-10-14",
                "locator": "Summary, heart attack symptoms"
              }
            ]
          },
          {
            "id": "ha-upper",
            "text": "Pain or discomfort in the upper body is another of the most common signs, felt in one or both arms, the back, the shoulders, the neck, the jaw or the upper stomach.",
            "cites": [
              {
                "snapshot_id": "cardio:medlineplus-heartattack-2026-10-14",
                "locator": "Summary, heart attack symptoms"
              }
            ]
          },
          {
            "id": "ha-other",
            "text": "Other signs include nausea, vomiting, dizziness, lightheadedness, a racing or pounding heart and a cold sweat.",
            "cites": [
              {
                "snapshot_id": "cardio:medlineplus-heartattack-2026-10-14",
                "locator": "Summary, heart attack symptoms"
              },
              {
                "snapshot_id": "cardio:medlineplus-heartattack-2026-10-14",
                "locator": "Summary, heart attack symptoms"
              }
            ]
          },
          {
            "id": "ha-women",
            "text": "Women’s symptoms sometimes differ from men’s, and women are more likely to feel tired for no reason.",
            "cites": [
              {
                "snapshot_id": "cardio:medlineplus-heartattack-2026-10-14",
                "locator": "Summary, heart attack symptoms"
              }
            ]
          },
          {
            "id": "ha-vary",
            "text": "Symptoms range from mild to severe, and they can differ from one person to the next.",
            "cites": [
              {
                "snapshot_id": "cardio:medlineplus-heartattack-2026-10-14",
                "locator": "Summary, heart attack symptoms"
              }
            ]
          }
        ],
        "act_now": [
          {
            "snapshot_id": "cardio:medlineplus-heartattack-2026-10-14",
            "locator": "Summary, what is a heart attack",
            "words": "If you are having symptoms of a heart attack, you should call 911, even if you are not sure it is a heart attack."
          },
          {
            "snapshot_id": "cardio:medlineplus-heartattack-2026-10-14",
            "locator": "Summary, what is a heart attack",
            "words": "it's important to know the symptoms of a heart attack and call 911 if you or someone else is having them."
          }
        ]
      },
      {
        "heading": "Signs of sudden cardiac arrest (SCA)",
        "signs": [
          {
            "id": "sca-faint",
            "text": "Loss of consciousness, or fainting, is usually the first sign of cardiac arrest.",
            "cites": [
              {
                "snapshot_id": "cardio:medlineplus-suddencardiacarrest-2026-10-15",
                "locator": "Summary, what are the symptoms of sudden cardiac arrest (SCA)"
              }
            ]
          },
          {
            "id": "sca-before",
            "text": "Some people feel dizzy or light-headed, or notice a racing heartbeat, shortly before they faint.",
            "cites": [
              {
                "snapshot_id": "cardio:medlineplus-suddencardiacarrest-2026-10-15",
                "locator": "Summary, what are the symptoms of sudden cardiac arrest (SCA)"
              }
            ]
          },
          {
            "id": "sca-hour",
            "text": "In the hour before cardiac arrest, some people have chest pain, shortness of breath, nausea or vomiting.",
            "cites": [
              {
                "snapshot_id": "cardio:medlineplus-suddencardiacarrest-2026-10-15",
                "locator": "Summary, what are the symptoms of sudden cardiac arrest (SCA)"
              }
            ]
          }
        ],
        "act_now": [
          {
            "snapshot_id": "cardio:medlineplus-suddencardiacarrest-2026-10-15",
            "locator": "Summary, what are the treatments for sudden cardiac arrest (SCA)",
            "words": "Call 9-1-1 right away if someone has signs or symptoms of SCA."
          },
          {
            "snapshot_id": "cardio:medlineplus-suddencardiacarrest-2026-10-15",
            "locator": "Summary, what are the treatments for sudden cardiac arrest (SCA)",
            "words": "The sooner you call for help, the sooner lifesaving treatment can begin."
          }
        ]
      }
    ],
    "sections": [
      {
        "heading": "More about signs, from NHLBI",
        "statements": [
          {
            "id": "nhlbi-slow",
            "text": "NHLBI says heart attack symptoms can build slowly, can be mild or sudden, and can start and stop over a span of several hours.",
            "cites": [
              {
                "snapshot_id": "cardio:nhlbi-heart-attack-symptoms-2026-10-15",
                "locator": "Page body, introduction"
              }
            ]
          },
          {
            "id": "nhlbi-differ",
            "text": "NHLBI says symptoms differ from person to person and between men and women, and may differ in a second heart attack.",
            "cites": [
              {
                "snapshot_id": "cardio:nhlbi-heart-attack-symptoms-2026-10-15",
                "locator": "Page body, introduction"
              },
              {
                "snapshot_id": "cardio:nhlbi-heart-attack-symptoms-2026-10-15",
                "locator": "Page body, introduction"
              }
            ]
          },
          {
            "id": "nhlbi-silent",
            "text": "NHLBI says a heart attack can cause no symptoms, or only mild ones, which it names a silent heart attack.",
            "cites": [
              {
                "snapshot_id": "cardio:nhlbi-heart-attack-symptoms-2026-10-15",
                "locator": "Page body, silent heart attacks"
              }
            ]
          },
          {
            "id": "nhlbi-groups",
            "text": "NHLBI links shortness of breath at rest or with light activity more closely to older adults, and unusual tiredness that can last for days more closely to women.",
            "cites": [
              {
                "snapshot_id": "cardio:nhlbi-heart-attack-symptoms-2026-10-15",
                "locator": "Page body, symptom list"
              },
              {
                "snapshot_id": "cardio:nhlbi-heart-attack-symptoms-2026-10-15",
                "locator": "Page body, symptom list"
              }
            ]
          },
          {
            "id": "nhlbi-collapse",
            "text": "NHLBI lists a sudden collapse with loss of consciousness as a sign of cardiac arrest.",
            "cites": [
              {
                "snapshot_id": "cardio:nhlbi-cardiac-arrest-2026-10-15",
                "locator": "Page body, signs of cardiac arrest"
              }
            ]
          },
          {
            "id": "nhlbi-breathing",
            "text": "NHLBI also lists not breathing, ineffective breathing, and gasping for air.",
            "cites": [
              {
                "snapshot_id": "cardio:nhlbi-cardiac-arrest-2026-10-15",
                "locator": "Page body, signs of cardiac arrest"
              }
            ]
          },
          {
            "id": "nhlbi-response",
            "text": "NHLBI adds no response to shouting or shaking, and no pulse, to its list.",
            "cites": [
              {
                "snapshot_id": "cardio:nhlbi-cardiac-arrest-2026-10-15",
                "locator": "Page body, signs of cardiac arrest"
              },
              {
                "snapshot_id": "cardio:nhlbi-cardiac-arrest-2026-10-15",
                "locator": "Page body, signs of cardiac arrest"
              }
            ]
          },
          {
            "id": "nhlbi-few",
            "text": "NHLBI says that most people with a cardiac arrest are not treated in time to survive.",
            "cites": [
              {
                "snapshot_id": "cardio:nhlbi-cardiac-arrest-2026-10-15",
                "locator": "Page body, what is cardiac arrest"
              }
            ]
          }
        ]
      },
      {
        "heading": "How a heart attack and cardiac arrest differ",
        "statements": [
          {
            "id": "diff-ha",
            "text": "In a heart attack, blood flow to the heart suddenly becomes blocked.",
            "cites": [
              {
                "snapshot_id": "cardio:medlineplus-heartattack-2026-10-14",
                "locator": "Summary, what is a heart attack"
              }
            ]
          },
          {
            "id": "diff-die",
            "text": "If a heart attack is not treated quickly, heart muscle starts to die.",
            "cites": [
              {
                "snapshot_id": "cardio:medlineplus-heartattack-2026-10-14",
                "locator": "Summary, what is a heart attack"
              }
            ]
          },
          {
            "id": "diff-quick",
            "text": "Quick treatment may prevent or limit damage to the heart muscle.",
            "cites": [
              {
                "snapshot_id": "cardio:medlineplus-heartattack-2026-10-14",
                "locator": "Summary, what is a heart attack"
              }
            ]
          },
          {
            "id": "diff-nostop",
            "text": "During a heart attack, the heart usually does not suddenly stop beating.",
            "cites": [
              {
                "snapshot_id": "cardio:medlineplus-heartattack-2026-10-14",
                "locator": "Summary, what is a heart attack"
              }
            ]
          },
          {
            "id": "diff-ca",
            "text": "MedlinePlus says that in a sudden cardiac arrest \"the heart stops beating and the person passes out\".",
            "cites": [
              {
                "snapshot_id": "cardio:medlineplus-heartattack-2026-10-14",
                "locator": "Summary, what is a heart attack"
              }
            ]
          },
          {
            "id": "diff-sca-name",
            "text": "MedlinePlus uses the short form SCA for sudden cardiac arrest.",
            "cites": [
              {
                "snapshot_id": "cardio:medlineplus-suddencardiacarrest-2026-10-15",
                "locator": "Summary, what is sudden cardiac arrest (SCA)"
              }
            ]
          },
          {
            "id": "diff-flow",
            "text": "When the heart stops, vital organs, including the brain, no longer get blood.",
            "cites": [
              {
                "snapshot_id": "cardio:medlineplus-suddencardiacarrest-2026-10-15",
                "locator": "Summary, what is sudden cardiac arrest (SCA)"
              }
            ]
          },
          {
            "id": "diff-death",
            "text": "Without treatment, cardiac arrest usually causes death within minutes.",
            "cites": [
              {
                "snapshot_id": "cardio:medlineplus-suddencardiacarrest-2026-10-15",
                "locator": "Summary, what is sudden cardiac arrest (SCA)"
              }
            ]
          },
          {
            "id": "sca-nowarn",
            "text": "MedlinePlus also says cardiac arrest happens without warning and needs emergency treatment.",
            "cites": [
              {
                "snapshot_id": "cardio:medlineplus-suddencardiacarrest-2026-10-15",
                "locator": "Summary, how is sudden cardiac arrest (SCA) diagnosed"
              }
            ]
          },
          {
            "id": "diff-trigger",
            "text": "A heart attack can trigger a sudden cardiac arrest, and MedlinePlus describes both as medical emergencies.",
            "cites": [
              {
                "snapshot_id": "cardio:medlineplus-heartattack-2026-10-14",
                "locator": "Summary, what is a heart attack"
              }
            ]
          }
        ]
      },
      {
        "heading": "What CPR is",
        "statements": [
          {
            "id": "cpr-name",
            "text": "CPR stands for cardiopulmonary resuscitation.",
            "cites": [
              {
                "snapshot_id": "cardio:medlineplus-suddencardiacarrest-2026-10-15",
                "locator": "Summary, what is sudden cardiac arrest (SCA)"
              }
            ]
          },
          {
            "id": "cpr-flow",
            "text": "CPR helps blood keep moving to the brain and other organs until the heart’s rhythm is restored.",
            "cites": [
              {
                "snapshot_id": "cardio:medlineplus-suddencardiacarrest-2026-10-15",
                "locator": "Summary, what are the treatments for sudden cardiac arrest (SCA)"
              }
            ]
          },
          {
            "id": "cpr-start",
            "text": "MedlinePlus says \"CPR should be started right away and continued until a defibrillator is ready to use.\"",
            "cites": [
              {
                "snapshot_id": "cardio:medlineplus-suddencardiacarrest-2026-10-15",
                "locator": "Summary, what are the treatments for sudden cardiac arrest (SCA)"
              }
            ]
          },
          {
            "id": "cpr-hands",
            "text": "MedlinePlus says that a person who has not been trained in CPR \"can still help by giving hands-only CPR\".",
            "cites": [
              {
                "snapshot_id": "cardio:medlineplus-suddencardiacarrest-2026-10-15",
                "locator": "Summary, what should I do if I think that someone has had an SCA"
              }
            ]
          },
          {
            "id": "cpr-how",
            "text": "MedlinePlus says hands-only CPR is done by \"pushing hard and fast on the center of the chest\".",
            "cites": [
              {
                "snapshot_id": "cardio:medlineplus-suddencardiacarrest-2026-10-15",
                "locator": "Summary, what should I do if I think that someone has had an SCA"
              }
            ]
          }
        ]
      },
      {
        "heading": "What an AED is",
        "statements": [
          {
            "id": "aed-name",
            "text": "AED stands for automated external defibrillator.",
            "cites": [
              {
                "snapshot_id": "cardio:medlineplus-suddencardiacarrest-2026-10-15",
                "locator": "Summary, what should I do if I think that someone has had an SCA"
              }
            ]
          },
          {
            "id": "aed-def",
            "text": "A defibrillator gives the heart an electric shock.",
            "cites": [
              {
                "snapshot_id": "cardio:medlineplus-suddencardiacarrest-2026-10-15",
                "locator": "Summary, what are the treatments for sudden cardiac arrest (SCA)"
              }
            ]
          },
          {
            "id": "aed-rhythm",
            "text": "The shock can bring back a normal rhythm in a heart that has stopped beating.",
            "cites": [
              {
                "snapshot_id": "cardio:medlineplus-suddencardiacarrest-2026-10-15",
                "locator": "Summary, what are the treatments for sudden cardiac arrest (SCA)"
              }
            ]
          },
          {
            "id": "aed-time",
            "text": "According to MedlinePlus, the shock needs to come within minutes of the cardiac arrest to work well.",
            "cites": [
              {
                "snapshot_id": "cardio:medlineplus-suddencardiacarrest-2026-10-15",
                "locator": "Summary, what are the treatments for sudden cardiac arrest (SCA)"
              }
            ]
          },
          {
            "id": "aed-places",
            "text": "MedlinePlus says many public places, such as schools, businesses and airports, have AEDs.",
            "cites": [
              {
                "snapshot_id": "cardio:medlineplus-suddencardiacarrest-2026-10-15",
                "locator": "Summary, what should I do if I think that someone has had an SCA"
              }
            ]
          },
          {
            "id": "aed-untrained",
            "text": "MedlinePlus says people without training can use an AED, and that it gives step-by-step voice instructions.",
            "cites": [
              {
                "snapshot_id": "cardio:medlineplus-suddencardiacarrest-2026-10-15",
                "locator": "Summary, what should I do if I think that someone has had an SCA"
              }
            ]
          },
          {
            "id": "aed-shock",
            "text": "An AED gives a shock if it detects a dangerous irregular heartbeat, which prevents a shock to someone who may have only fainted.",
            "cites": [
              {
                "snapshot_id": "cardio:medlineplus-suddencardiacarrest-2026-10-15",
                "locator": "Summary, what should I do if I think that someone has had an SCA"
              },
              {
                "snapshot_id": "cardio:medlineplus-suddencardiacarrest-2026-10-15",
                "locator": "Summary, what should I do if I think that someone has had an SCA"
              }
            ]
          },
          {
            "id": "aed-responders",
            "text": "MedlinePlus says most police officers, emergency medical technicians and other first responders are \"trained and equipped to use a defibrillator\".",
            "cites": [
              {
                "snapshot_id": "cardio:medlineplus-suddencardiacarrest-2026-10-15",
                "locator": "Summary, what are the treatments for sudden cardiac arrest (SCA)"
              }
            ]
          },
          {
            "id": "aed-train",
            "text": "NHLBI says using an AED is not difficult, and that training helps a great deal.",
            "cites": [
              {
                "snapshot_id": "cardio:nhlbi-cardiac-arrest-2026-10-15",
                "locator": "Page body, AED section"
              }
            ]
          },
          {
            "id": "aed-classes",
            "text": "NHLBI also says AED training often comes with CPR training, and that classes are offered by many major health groups.",
            "cites": [
              {
                "snapshot_id": "cardio:nhlbi-cardiac-arrest-2026-10-15",
                "locator": "Page body, AED section"
              }
            ]
          },
          {
            "id": "aed-home-mlp",
            "text": "MedlinePlus says people at risk of cardiac arrest \"may want to consider having an AED at home\".",
            "cites": [
              {
                "snapshot_id": "cardio:medlineplus-suddencardiacarrest-2026-10-15",
                "locator": "Summary, what should I do if I think that someone has had an SCA"
              }
            ]
          },
          {
            "id": "aed-home-nhlbi",
            "text": "NHLBI says providers sometimes advise an AED at home when a person’s risk of cardiac arrest is high.",
            "cites": [
              {
                "snapshot_id": "cardio:nhlbi-defibrillators-2026-10-15",
                "locator": "Page body, types of defibrillators"
              }
            ]
          }
        ]
      },
      {
        "heading": "One cardiac arrest risk that MedlinePlus names",
        "statements": [
          {
            "id": "risk-cad",
            "text": "Most people with cardiac arrest have coronary artery disease, which usually causes no symptoms.",
            "cites": [
              {
                "snapshot_id": "cardio:medlineplus-suddencardiacarrest-2026-10-15",
                "locator": "Summary, who is at risk for sudden cardiac arrest (SCA)"
              },
              {
                "snapshot_id": "cardio:medlineplus-suddencardiacarrest-2026-10-15",
                "locator": "Summary, who is at risk for sudden cardiac arrest (SCA)"
              }
            ]
          }
        ]
      }
    ],
    "checklists": [
      {
        "heading": "Topics from the NHLBI cardiac arrest page",
        "items": [
          {
            "id": "chk-signs",
            "text": "The signs of cardiac arrest.",
            "cites": [
              {
                "snapshot_id": "cardio:nhlbi-cardiac-arrest-2026-10-15",
                "locator": "Page body, AED section"
              }
            ]
          },
          {
            "id": "chk-where",
            "text": "Where AEDs are kept in offices, schools and other public places.",
            "cites": [
              {
                "snapshot_id": "cardio:nhlbi-cardiac-arrest-2026-10-15",
                "locator": "Page body, AED section"
              }
            ]
          },
          {
            "id": "chk-learn",
            "text": "How to use an AED, including classes from major health organizations.",
            "cites": [
              {
                "snapshot_id": "cardio:nhlbi-cardiac-arrest-2026-10-15",
                "locator": "Page body, AED section"
              },
              {
                "snapshot_id": "cardio:nhlbi-cardiac-arrest-2026-10-15",
                "locator": "Page body, AED section"
              }
            ]
          }
        ]
      }
    ],
    "questions": [
      {
        "text": "Can a heart attack happen with no symptoms, or only very mild ones?",
        "grounded_in": [
          "nhlbi-silent"
        ]
      },
      {
        "text": "Which heart attack symptoms are more common in women, and which in older adults?",
        "grounded_in": [
          "ha-women",
          "nhlbi-groups"
        ]
      },
      {
        "text": "Does my heart health put me at a higher risk of cardiac arrest?",
        "grounded_in": [
          "risk-cad"
        ]
      },
      {
        "text": "Would an AED at home make sense for someone with my heart condition?",
        "grounded_in": [
          "aed-home-mlp",
          "aed-home-nhlbi"
        ]
      },
      {
        "text": "Where can I learn CPR and how to use an AED?",
        "grounded_in": [
          "aed-train",
          "aed-classes",
          "chk-learn"
        ]
      }
    ]
  },
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    "incoming": []
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  "page_path": "guides/heart-attack-or-cardiac-arrest-what-to-do-now/",
  "context_path": "api/v1/context/cardio--guide-heart-attack-cardiac-arrest-now.md"
}