Table 1.

Definitions for the etiology of cardiac arrest based on the Advanced Resuscitation Training (ART) Matrix.

A cardiac arrest is presumed to be of the following aetiology if deterioration can be primarily attributed to the following:
Ventilation		Intubated
Hypoxemia which may be due to known pulmonary disease (pneumonia, chronic obstructive pulmonary disease, asthma, etc.) or with airway obstruction that accompanies a decrease in mental status (due to analgesia/sedation, sleep apnea, hypoglycemia, etc.). Patients are further divided based on airway access prior to the arrest.		Non-intubated
		Tracheostomy
		Rapid sequence intubation
		Includes cardiac arrest as a complication following airway management initiation
Circulation		Sepsis
Hypoperfusion which may be due to loss of intravascular volume (including blood loss or fluid shift into the interstitial space), obstruction of forward flow, or secondary to impaired cardiac function.		Clinical syndrome that results from a dysregulated inflammatory response to infection
		Hemorrhage
		Includes gastrointestinal bleeding and postoperative blood loss
		Pulmonary embolus
		Cardiac dysfunction
		Includes congestive heart failure and constrictive disease (ie. pericardial effusion)
Dysrhythmia		Ventricular fibrillation/ventricular tachycardia
Abnormality in the rate, regularity, or rhythm of cardiac electrical activity as the primary cause of cardiac arrest.		Vagal
		Identified as cardiac arrests preceded by bradycardia in the setting of an identifiable vagal stimulus (i.e. micturation, defecation, deep oral suctioning, position change, etc.)
Neurological
Acute neurological deficits or alteration in mental status, not attributable to hypoperfusion, hypoxemia, or hypoglycemia, which may include cerebrovascular accident or intracranial hemorrhage.
Unknown
Cause of arrest is not know n or could not be classified as any of the options above.