cardiac arrest
Enable an AI agent to recognise suspected cardiac arrest, represent an episode and its uncertainty, and support timely escalation and authorised clinical decisions.
Research draft, second pass
A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.
recalled by Codex without web access - no source was read
Researched by: Codex
Purpose and description
Enable an AI agent to recognise suspected cardiac arrest, represent an episode and its uncertainty, and support timely escalation and authorised clinical decisions.
Cardiac arrest is the cessation of effective cardiac mechanical activity, resulting in loss of effective blood circulation and clinically recognised by unresponsiveness, absent normal breathing and absence of a definite pulse.
It can be Flag observations consistent with suspected arrest and support emergency-response activation through the applicable workflow.; Assemble a timestamped arrest record from witness reports, monitor data and clinical observations.; Expose missing or contradictory evidence without delaying the emergency response to complete documentation.; Surface the applicable resuscitation pathway using rhythm, patient group and special circumstances.; Track response to interventions and prepare a handover after return of circulation or transfer.; Identify decisions requiring accountable clinicians, including withholding or ending resuscitation..
Distinguishing features
Cardiac arrest concerns absent effective cardiac circulation; myocardial infarction concerns myocardial injury from ischaemia and may occur with circulation preserved.
An organised electrical rhythm does not establish effective circulation: pulseless electrical activity remains an arrest rhythm.
Unresponsiveness with absent or abnormal breathing, including gasping, supports emergency recognition; record whether this is a lay recognition or a professional assessment. [AHA adult basic life support](https://cpr.heart.org/en/resuscitation-science/cpr-and-ecc-guidelines/adult-basic-life-support)
Respiratory arrest alone retains circulation, whereas cardiac arrest requires assessment of circulatory failure.
Cardiac arrest is potentially reversible; neither its occurrence nor ongoing CPR alone establishes irreversible death.
Scope
+ Evidence supporting suspected or clinically established cardiac arrest
+ Arrest onset, recognition, circulation states and recurrent episodes
+ Arrest rhythms and changes relevant to response
+ Suspected causes, precipitating circumstances and supporting evidence
+ Resuscitation actions, applicable authority and immediate outcomes
- Myocardial infarction, heart failure and other underlying diseases as independently modelled conditions
- Respiratory arrest with effective circulation preserved
- Detailed CPR procedures, drug regimens and resuscitation-device specifications
- Longitudinal management of post-cardiac-arrest syndrome and rehabilitation
- Independent determination of death and organ-donation processes
Characteristics
- Recognition status
- suspected | clinically established | subsequently excluded | indeterminate Separates the threshold for emergency response from later diagnostic adjudication.
- Responsiveness and breathing
- Responsiveness: responsive | unresponsive | unknown; breathing: normal | absent | agonal or abnormal | assisted | unknown Preserves the observations used to recognise arrest without treating assisted ventilation as spontaneous breathing.
- Circulatory evidence
- Pulse, arterial waveform or other clinical evidence; present | absent | uncertain | not assessed, with assessor and time Documents the basis for judging effective circulation and its return.
- Arrest rhythm
- ventricular fibrillation | pulseless ventricular tachycardia | pulseless electrical activity | asystole | other | unknown Supports rhythm-specific response while distinguishing electrical activity from perfusion.
- Episode timing
- Timestamped events; elapsed seconds or minutes; observed, estimated or unknown Separates collapse, recognition, first CPR, first shock and return of circulation.
- Witness and setting
- Witnessed | unwitnessed | unknown; monitored status; out-of-hospital | in-hospital | other setting Explains the reliability of onset estimates and available response resources.
- Circulation phase
- arrest without support | CPR-supported circulation | extracorporeal support | spontaneous circulation restored | recurrent arrest | unknown Prevents mechanically supported flow from being recorded as spontaneous recovery.
- Suspected aetiology
- Links to candidate causes with evidence, confidence and assessment time Allows competing explanations and cause-directed evaluation.
- Applicable resuscitation pathway
- Protocol identifier and version, patient group, jurisdiction and responsible team Avoids applying one adult pathway to every age group or special circumstance.
- Immediate outcome
- ongoing resuscitation | transient return of spontaneous circulation | sustained return under a stated definition | supported circulation | resuscitation ended without return | unknown Keeps immediate episode outcomes distinct from survival and neurological recovery.
Also called
Where this came from
wikidata · CC0 1.0
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 6 bundles · 11 layers · 19 findings · 29 questions.
Recognition and boundaries Represent why an episode is considered cardiac arrest and distinguish it from neighbouring conditions.
Emergency recognition must support action despite incomplete evidence while preserving diagnostic uncertainty.
Observable arrest signs
Capture the initial observations and who made them.
Recognition evidence
Record responsiveness, breathing and circulatory assessment separately, including uncertainty and observer role; gasping can mislead recognition. [AHA adult basic life support](https://cpr.heart.org/en/resuscitation-science/cpr-and-ecc-guidelines/adult-basic-life-support)
- What responsiveness, breathing and circulatory observations supported suspected arrest, and when were they obtained? measurement
- Who made each observation, using which assessment method or device? provenance
Clinical state boundaries
Separate cardiac arrest from conditions with overlapping presentations.
Effective circulation boundary
Model the absence of effective cardiac circulation rather than unconsciousness, absent breathing or an ECG appearance alone.
- What evidence distinguishes this episode from syncope, seizure or respiratory arrest with circulation preserved? boundary
- Was the initial arrest classification retained, revised or left indeterminate after clinical assessment? definition
Episode time and circulation Represent the sequence from collapse through resuscitation and changes in circulation.
Arrest duration and state transitions cannot be inferred reliably from a single diagnosis timestamp.
Onset and response intervals
Separate observed events from reconstructed intervals.
Timing with uncertainty
Record collapse, recognition and intervention times with their sources; do not substitute discovery time for an unknown onset.
- Which times are observed, estimated or unknown, and do the recording clocks agree? provenance
- What intervals without CPR or with CPR can be supported, and what uncertainty or interruptions affect them? measurement
Circulation transitions
Track absent, supported and restored circulation across the episode.
Return and recurrence
Represent return of spontaneous circulation, extracorporeal support and recurrent arrest as distinct events, each supported by clinical evidence.
- What evidence and timestamp establish each return or subsequent loss of spontaneous circulation? measurement
- Under the selected episode definition, does a recurrence continue this episode or start a linked episode? boundary
Rhythm and cause Connect electrical findings and candidate causes to the evolving arrest state.
Rhythm guides immediate response but does not uniquely identify the cause.
Rhythm assessment
Preserve time-specific rhythm classifications and their evidential basis.
Shockability and perfusion
Ventricular fibrillation and pulseless ventricular tachycardia occupy the shockable branch; pulseless electrical activity and asystole occupy the nonshockable branch. [AHA adult advanced life support](https://cpr.heart.org/en/resuscitation-science/cpr-and-ecc-guidelines/adult-advanced-life-support)
- What was the first recorded rhythm, and how did later assessed rhythms differ? measurement
- Was classification based on a reviewed tracing, an AED analysis or another assessment, and was artefact considered? provenance
Aetiology and special circumstances
Maintain cause hypotheses and factors that change the applicable clinical pathway.
Cause evidence and modifiers
Represent suspected causes independently of rhythm and flag circumstances such as drowning, hypothermia, poisoning or pregnancy that may require tailored management. [AHA special circumstances](https://cpr.heart.org/en/resuscitation-science/cpr-and-ecc-guidelines/adult-and-pediatric-special-circumstances-of-resuscitation)
- Which candidate causes are supported or contradicted by the history, examination and investigations? provenance
- Which patient or environmental circumstances require a different resuscitation pathway? action
Resuscitation response and authority Record the response delivered and the authority governing major treatment decisions.
The model must distinguish observed care, recommended pathways and decisions entrusted to responsible clinicians.
Interventions and response
Link resuscitation interventions to timing and subsequent observations.
Resuscitation delivery
Capture CPR, rhythm analyses, shocks, ventilation and advanced interventions as time-linked events, including interruptions and measured response.
- Which interventions were delivered, by whom and when, and which significant interruptions occurred? provenance
- What changes in rhythm or circulation followed each intervention without assuming that temporal association proves causation? measurement
Treatment limits and accountability
Represent the applicable protocol and documented decisions to start, continue, withhold or end resuscitation.
Decision authority
Record clinician decisions, cited protocols and verified treatment-limitation documents separately from arrest physiology; the model does not infer permission to stop from duration alone.
- Which protocol and any verified treatment-limitation document apply to this patient and setting? provenance
- Who authorised withholding or ending resuscitation, and what documented assessment supported that decision? action
Outcomes and care transition Represent the episode outcome and transfer responsibility to subsequent care.
Return of circulation is an intermediate outcome and does not establish survival or neurological recovery.
Immediate outcome evidence
Separate circulation outcomes from later survival endpoints.
Endpoint-specific outcomes
Record return of circulation, status at transfer and later linked survival assessments with explicit times and definitions; retain unknown outcomes.
- What outcome was established at the end of observation, and at which time? measurement
- Which operational definition distinguishes transient from sustained return of spontaneous circulation? definition
Post-arrest handover
Transfer the information needed for evaluation and care after circulation returns.
Ongoing risk and handover
Link restored circulation to further assessment of underlying cause, physiological instability and complications; subsequent neurological assessment belongs to post-arrest care. [AHA post-cardiac-arrest care](https://cpr.heart.org/en/resuscitation-science/cpr-and-ecc-guidelines/post-cardiac-arrest-care)
- Which unresolved causes, recurrent-arrest risks and current support requirements must accompany the handover? action
- Which receiving team and linked care record assume responsibility after the arrest episode? provenance
Evidence and external alignment What the world already says about this thing, gathered so the model can be checked against it.
A model that cannot be lined up against existing standards, identifiers and practice cannot be adopted by anyone who already uses them.
Reported evidence
Findings from the breadth pass, kept separate from the structural claims.
Check these first
Recalled without web access and unsourced; every item is a lead to verify.
- This describes the clinical condition, despite its placement in an abstract-concept batch; all content is recalled rather than source-verified.
- Check current guideline editions and jurisdiction-specific coding instructions before operational use.
- Arrest rhythm can change during an episode; initial rhythm, location, witnessed status and cause are separate classification dimensions.
- Which of these check these first hold for the sense of cardiac arrest this model covers, and on what evidence? provenance
Kinds and varieties
Recalled without web access and unsourced; every item is a lead to verify.
- Ventricular fibrillation arrest
- Pulseless ventricular tachycardia arrest
- Pulseless electrical activity arrest
- Asystolic arrest
- Which of these kinds and varieties hold for the sense of cardiac arrest this model covers, and on what evidence? provenance
Identifiers and schemes
Recalled without web access and unsourced; every item is a lead to verify.
- ICD-10 - I46 - Cardiac arrest category; subcodes and coding instructions depend on the national modification and circumstances.
- Which of these identifiers and schemes hold for the sense of cardiac arrest this model covers, and on what evidence? provenance
Standards and regulation
Recalled without web access and unsourced; every item is a lead to verify.
- International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations, issued by the International Liaison Committee on Resuscitation.
- Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care, issued by the American Heart Association.
- Resuscitation Guidelines, issued by the European Resuscitation Council.
- Utstein-style reporting templates for cardiac arrest and resuscitation, developed through international resuscitation council collaboration.
- Which of these standards and regulation hold for the sense of cardiac arrest this model covers, and on what evidence? provenance
Real-world use
Recalled without web access and unsourced; every item is a lead to verify.
- Recognition and classification of a medical emergency requiring resuscitation.
- Organisation of emergency dispatch, bystander response and automated external defibrillator programmes.
- Hospital surveillance and improvement of resuscitation systems.
- Cardiac arrest registries and comparisons of outcomes across emergency care systems.
- Investigation of underlying cardiac and noncardiac causes.
- Which of these real-world use hold for the sense of cardiac arrest this model covers, and on what evidence? provenance
Typical measurements
Recalled without web access and unsourced; every item is a lead to verify.
- Time from collapse to initiation of cardiopulmonary resuscitation - Variable; collapse time may be unknown in unwitnessed arrests. - minutes
- Time from collapse to first defibrillation - Variable; applicable when a shockable rhythm is present. - minutes
- Survival to hospital discharge - Varies substantially with setting, cause, initial rhythm and case definition. - percent of a defined cardiac arrest cohort
- Which of these typical measurements hold for the sense of cardiac arrest this model covers, and on what evidence? provenance
Failure modes and hazards
Recalled without web access and unsourced; every item is a lead to verify.
- Rapid hypoxic-ischaemic brain injury and death if circulation is not restored.
- Delayed recognition because agonal gasps are mistaken for normal breathing.
- Confusion between electrical activity on a monitor and effective mechanical circulation.
- Recurrent arrest after return of spontaneous circulation.
- Post-cardiac arrest syndrome, including brain injury, myocardial dysfunction and systemic ischaemia-reperfusion injury.
- Which of these failure modes and hazards hold for the sense of cardiac arrest this model covers, and on what evidence? provenance
Regional variation
Recalled without web access and unsourced; every item is a lead to verify.
- Resuscitation guidance is adapted by regional and national bodies from international evidence reviews.
- Emergency response systems, public defibrillator access and registry coverage vary across jurisdictions.
- Rules governing resuscitation decisions and termination of resuscitation vary by jurisdiction.
- Which of these regional variation hold for the sense of cardiac arrest this model covers, and on what evidence? provenance
Neighbouring kinds and how to tell them apart
Recalled without web access and unsourced; every item is a lead to verify.
- Myocardial infarction - Myocardial infarction involves heart muscle injury from ischaemia; cardiac arrest involves loss of effective circulation. Either can occur without the other.
- Heart failure - Heart failure is a clinical syndrome caused by impaired cardiac filling or output; circulation usually persists.
- Respiratory arrest - Respiratory arrest is cessation of effective breathing; cardiac circulation may initially continue.
- Syncope - Syncope is transient loss of consciousness from cerebral hypoperfusion with spontaneous recovery; loss of consciousness alone does not establish cardiac arrest.
- Sudden cardiac death - Sudden cardiac death is a fatal outcome attributed to a cardiac cause; cardiac arrest can be survived and can have noncardiac causes.
- Which of these neighbouring kinds and how to tell them apart hold for the sense of cardiac arrest this model covers, and on what evidence? provenance
What the second pass must settle
- Which existing Vercy world model, if any, already owns cardiac arrest and should be linked rather than duplicated?
- Which operational standard should define episode boundaries, sustained return of spontaneous circulation and recurrent arrest?
- How should paediatric arrest and neonatal resuscitation relate to this entry, particularly interventions begun before complete circulatory arrest?
- How should effective circulation be operationalised when mechanical circulatory support makes pulse-based recognition unreliable?
- Which jurisdiction-specific protocols and verification requirements govern treatment limitations and termination decisions in the intended deployment?